text: from __future__ import unicode_literals
  
  import copy
  import itertools
  import ipaddress
  import json
  import os
  import re
  import six
  import warnings
  
  from boto3 import Session
  from pkg_resources import resource_filename
  
  from collections import defaultdict
  import weakref
  from datetime import datetime
  from boto.ec2.instance import Instance as BotoInstance, Reservation
  from boto.ec2.blockdevicemapping import BlockDeviceMapping, BlockDeviceType
  from boto.ec2.spotinstancerequest import SpotInstanceRequest as BotoSpotRequest
  from boto.ec2.launchspecification import LaunchSpecification
  
  from moto.compat import OrderedDict
  from moto.core import BaseBackend
  from moto.core.models import Model, BaseModel, CloudFormationModel
  from moto.core.utils import (
      iso_8601_datetime_with_milliseconds,
      camelcase_to_underscores,
  )
  from moto.core import ACCOUNT_ID
  from moto.kms import kms_backends
  
  from .exceptions import (
      CidrLimitExceeded,
      DependencyViolationError,
      EC2ClientError,
      FilterNotImplementedError,
      FlowLogAlreadyExists,
      GatewayNotAttachedError,
      InvalidAddressError,
      InvalidAllocationIdError,
      InvalidAMIIdError,
      InvalidAMIAttributeItemValueError,
      InvalidAssociationIdError,
      InvalidAvailabilityZoneError,
      InvalidCIDRBlockParameterError,
      InvalidCIDRSubnetError,
      InvalidCustomerGatewayIdError,
      InvalidDestinationCIDRBlockParameterError,
      InvalidDHCPOptionsIdError,
      InvalidDomainError,
      InvalidID,
      InvalidInstanceIdError,
      InvalidInternetGatewayIdError,
      InvalidKeyPairDuplicateError,
      InvalidKeyPairFormatError,
      InvalidKeyPairNameError,
      InvalidAggregationIntervalParameterError,
      InvalidDependantParameterError,
      InvalidDependantParameterTypeError,
      InvalidFlowLogIdError,
      InvalidLaunchTemplateNameError,
      InvalidNetworkAclIdError,
      InvalidNetworkAttachmentIdError,
      InvalidNetworkInterfaceIdError,
      InvalidParameterValueError,
      InvalidParameterValueErrorTagNull,
      InvalidParameterValueErrorUnknownAttribute,
      InvalidPermissionNotFoundError,
      InvalidPermissionDuplicateError,
      InvalidRouteTableIdError,
      InvalidRouteError,
      InvalidSecurityGroupDuplicateError,
      InvalidSecurityGroupNotFoundError,
      InvalidSnapshotIdError,
      InvalidSubnetConflictError,
      InvalidSubnetIdError,
      InvalidSubnetRangeError,
      InvalidVolumeIdError,
      VolumeInUseError,
      InvalidVolumeAttachmentError,
      InvalidVolumeDetachmentError,
      InvalidVpcCidrBlockAssociationIdError,
      InvalidVPCPeeringConnectionIdError,
      InvalidVPCPeeringConnectionStateTransitionError,
      InvalidVPCIdError,
      InvalidVPCRangeError,
      InvalidVpnGatewayIdError,
      InvalidVpnConnectionIdError,
      MalformedAMIIdError,
      MalformedDHCPOptionsIdError,
      MissingParameterError,
      MotoNotImplementedError,
      NetworkAclEntryAlreadyExistsError,
      OperationNotPermitted,
      OperationNotPermitted2,
      OperationNotPermitted3,
      ResourceAlreadyAssociatedError,
      RulesPerSecurityGroupLimitExceededError,
      TagLimitExceeded,
      InvalidParameterDependency,
  )
  from .utils import (
      EC2_RESOURCE_TO_PREFIX,
      EC2_PREFIX_TO_RESOURCE,
      random_ami_id,
      random_dhcp_option_id,
      random_eip_allocation_id,
      random_eip_association_id,
      random_eni_attach_id,
      random_eni_id,
      random_instance_id,
      random_internet_gateway_id,
      random_ip,
      random_ipv6_cidr,
      randor_ipv4_cidr,
      random_launch_template_id,
      random_nat_gateway_id,
      random_key_pair,
      random_private_ip,
      random_public_ip,
      random_reservation_id,
      random_route_table_id,
      generate_route_id,
      generate_vpc_end_point_id,
      create_dns_entries,
      split_route_id,
      random_security_group_id,
      random_snapshot_id,
      random_spot_fleet_request_id,
      random_spot_request_id,
      random_subnet_id,
      random_subnet_association_id,
      random_flow_log_id,
      random_volume_id,
      random_vpc_id,
      random_vpc_cidr_association_id,
      random_vpc_peering_connection_id,
      generic_filter,
      is_valid_resource_id,
      get_prefix,
      simple_aws_filter_to_re,
      is_valid_cidr,
      filter_internet_gateways,
      filter_reservations,
      random_network_acl_id,
      random_network_acl_subnet_association_id,
      random_vpn_gateway_id,
      random_vpn_connection_id,
      random_customer_gateway_id,
      is_tag_filter,
      tag_filter_matches,
      rsa_public_key_parse,
      rsa_public_key_fingerprint,
  )
  
  
  def _load_resource(filename):
      with open(filename, "r") as f:
          return json.load(f)
  
  
  INSTANCE_TYPES = _load_resource(
      resource_filename(__name__, "resources/instance_types.json")
  )
  
  AMIS = _load_resource(
      os.environ.get("MOTO_AMIS_PATH")
      or resource_filename(__name__, "resources/amis.json"),
  )
  
  OWNER_ID = ACCOUNT_ID
  
  
  def utc_date_and_time():
      return datetime.utcnow().strftime("%Y-%m-%dT%H:%M:%S.000Z")
  
  
  def validate_resource_ids(resource_ids):
      if not resource_ids:
          raise MissingParameterError(parameter="resourceIdSet")
      for resource_id in resource_ids:
          if not is_valid_resource_id(resource_id):
              raise InvalidID(resource_id=resource_id)
      return True
  
  
  class InstanceState(object):
      def __init__(self, name="pending", code=0):
          self.name = name
          self.code = code
  
  
  class StateReason(object):
      def __init__(self, message="", code=""):
          self.message = message
          self.code = code
  
  
  class TaggedEC2Resource(BaseModel):
      def get_tags(self, *args, **kwargs):
          tags = self.ec2_backend.describe_tags(filters={"resource-id": [self.id]})
          return tags
  
      def add_tag(self, key, value):
          self.ec2_backend.create_tags([self.id], {key: value})
  
      def add_tags(self, tag_map):
          for key, value in tag_map.items():
              self.ec2_backend.create_tags([self.id], {key: value})
  
      def get_filter_value(self, filter_name, method_name=None):
          tags = self.get_tags()
  
          if filter_name.startswith("tag:"):
              tagname = filter_name.replace("tag:", "", 1)
              for tag in tags:
                  if tag["key"] == tagname:
                      return tag["value"]
  
              return ""
          elif filter_name == "tag-key":
              return [tag["key"] for tag in tags]
          elif filter_name == "tag-value":
              return [tag["value"] for tag in tags]
          else:
              raise FilterNotImplementedError(filter_name, method_name)
  
  
  class NetworkInterface(TaggedEC2Resource, CloudFormationModel):
      def __init__(
          self,
          ec2_backend,
          subnet,
          private_ip_address,
          private_ip_addresses=None,
          device_index=0,
          public_ip_auto_assign=True,
          group_ids=None,
          description=None,
      ):
          self.ec2_backend = ec2_backend
          self.id = random_eni_id()
          self.device_index = device_index
          self.private_ip_address = private_ip_address or random_private_ip()
          self.private_ip_addresses = private_ip_addresses
          self.subnet = subnet
          self.instance = None
          self.attachment_id = None
          self.description = description
  
          self.public_ip = None
          self.public_ip_auto_assign = public_ip_auto_assign
          self.start()
  
          self.attachments = []
  
          # Local set to the ENI. When attached to an instance, @property group_set
          #   returns groups for both self and the attached instance.
          self._group_set = []
  
          group = None
          if group_ids:
              for group_id in group_ids:
                  group = self.ec2_backend.get_security_group_from_id(group_id)
                  if not group:
                      # Create with specific group ID.
                      group = SecurityGroup(
                          self.ec2_backend,
                          group_id,
                          group_id,
                          group_id,
                          vpc_id=subnet.vpc_id,
                      )
                      self.ec2_backend.groups[subnet.vpc_id][group_id] = group
                  if group:
                      self._group_set.append(group)
  
      @staticmethod
      def cloudformation_name_type():
          return None
  
      @staticmethod
      def cloudformation_type():
          # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-networkinterface.html
          return "AWS::EC2::NetworkInterface"
  
      @classmethod
      def create_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          properties = cloudformation_json["Properties"]
  
          security_group_ids = properties.get("SecurityGroups", [])
  
          ec2_backend = ec2_backends[region_name]
          subnet_id = properties.get("SubnetId")
          if subnet_id:
              subnet = ec2_backend.get_subnet(subnet_id)
          else:
              subnet = None
  
          private_ip_address = properties.get("PrivateIpAddress", None)
          description = properties.get("Description", None)
  
          network_interface = ec2_backend.create_network_interface(
              subnet,
              private_ip_address,
              group_ids=security_group_ids,
              description=description,
          )
          return network_interface
  
      def stop(self):
          if self.public_ip_auto_assign:
              self.public_ip = None
  
      def start(self):
          self.check_auto_public_ip()
  
      def check_auto_public_ip(self):
          if self.public_ip_auto_assign:
              self.public_ip = random_public_ip()
  
      @property
      def group_set(self):
          if self.instance and self.instance.security_groups:
              return set(self._group_set) | set(self.instance.security_groups)
          else:
              return self._group_set
  
      def get_cfn_attribute(self, attribute_name):
          from moto.cloudformation.exceptions import UnformattedGetAttTemplateException
  
          if attribute_name == "PrimaryPrivateIpAddress":
              return self.private_ip_address
          elif attribute_name == "SecondaryPrivateIpAddresses":
              raise NotImplementedError(
                  '"Fn::GetAtt" : [ "{0}" , "SecondaryPrivateIpAddresses" ]"'
              )
          raise UnformattedGetAttTemplateException()
  
      @property
      def physical_resource_id(self):
          return self.id
  
      def get_filter_value(self, filter_name):
          if filter_name == "network-interface-id":
              return self.id
          elif filter_name in ("addresses.private-ip-address", "private-ip-address"):
              return self.private_ip_address
          elif filter_name == "subnet-id":
              return self.subnet.id
          elif filter_name == "vpc-id":
              return self.subnet.vpc_id
          elif filter_name == "group-id":
              return [group.id for group in self._group_set]
          elif filter_name == "availability-zone":
              return self.subnet.availability_zone
          elif filter_name == "description":
              return self.description
          else:
              return super(NetworkInterface, self).get_filter_value(
                  filter_name, "DescribeNetworkInterfaces"
              )
  
  
  class NetworkInterfaceBackend(object):
      def __init__(self):
          self.enis = {}
          super(NetworkInterfaceBackend, self).__init__()
  
      def create_network_interface(
          self,
          subnet,
          private_ip_address,
          private_ip_addresses=None,
          group_ids=None,
          description=None,
          **kwargs
      ):
          eni = NetworkInterface(
              self,
              subnet,
              private_ip_address,
              private_ip_addresses,
              group_ids=group_ids,
              description=description,
              **kwargs
          )
          self.enis[eni.id] = eni
          return eni
  
      def get_network_interface(self, eni_id):
          for eni in self.enis.values():
              if eni_id == eni.id:
                  return eni
          raise InvalidNetworkInterfaceIdError(eni_id)
  
      def delete_network_interface(self, eni_id):
          deleted = self.enis.pop(eni_id, None)
          if not deleted:
              raise InvalidNetworkInterfaceIdError(eni_id)
          return deleted
  
      def describe_network_interfaces(self, filters=None):
          enis = self.enis.values()
  
          if filters:
              for (_filter, _filter_value) in filters.items():
                  if _filter == "network-interface-id":
                      _filter = "id"
                      enis = [
                          eni for eni in enis if getattr(eni, _filter) in _filter_value
                      ]
                  elif _filter == "group-id":
                      original_enis = enis
                      enis = []
                      for eni in original_enis:
                          for group in eni.group_set:
                              if group.id in _filter_value:
                                  enis.append(eni)
                                  break
                  elif _filter == "private-ip-address:":
                      enis = [
                          eni for eni in enis if eni.private_ip_address in _filter_value
                      ]
                  elif _filter == "subnet-id":
                      enis = [eni for eni in enis if eni.subnet.id in _filter_value]
                  elif _filter == "description":
                      enis = [eni for eni in enis if eni.description in _filter_value]
                  else:
                      self.raise_not_implemented_error(
                          "The filter '{0}' for DescribeNetworkInterfaces".format(_filter)
                      )
          return enis
  
      def attach_network_interface(self, eni_id, instance_id, device_index):
          eni = self.get_network_interface(eni_id)
          instance = self.get_instance(instance_id)
          return instance.attach_eni(eni, device_index)
  
      def detach_network_interface(self, attachment_id):
          found_eni = None
  
          for eni in self.enis.values():
              if eni.attachment_id == attachment_id:
                  found_eni = eni
                  break
          else:
              raise InvalidNetworkAttachmentIdError(attachment_id)
  
          found_eni.instance.detach_eni(found_eni)
  
      def modify_network_interface_attribute(self, eni_id, group_id):
          eni = self.get_network_interface(eni_id)
          group = self.get_security_group_from_id(group_id)
          eni._group_set = [group]
  
      def get_all_network_interfaces(self, eni_ids=None, filters=None):
          enis = self.enis.values()
  
          if eni_ids:
              enis = [eni for eni in enis if eni.id in eni_ids]
              if len(enis) != len(eni_ids):
                  invalid_id = list(
                      set(eni_ids).difference(set([eni.id for eni in enis]))
                  )[0]
                  raise InvalidNetworkInterfaceIdError(invalid_id)
  
          return generic_filter(filters, enis)
  
  
  class Instance(TaggedEC2Resource, BotoInstance, CloudFormationModel):
      VALID_ATTRIBUTES = {
          "instanceType",
          "kernel",
          "ramdisk",
          "userData",
          "disableApiTermination",
          "instanceInitiatedShutdownBehavior",
          "rootDeviceName",
          "blockDeviceMapping",
          "productCodes",
          "sourceDestCheck",
          "groupSet",
          "ebsOptimized",
          "sriovNetSupport",
      }
  
      def __init__(self, ec2_backend, image_id, user_data, security_groups, **kwargs):
          super(Instance, self).__init__()
          self.ec2_backend = ec2_backend
          self.id = random_instance_id()
          self.image_id = image_id
          self._state = InstanceState("running", 16)
          self._reason = ""
          self._state_reason = StateReason()
          self.user_data = user_data
          self.security_groups = security_groups
          self.instance_type = kwargs.get("instance_type", "m1.small")
          self.region_name = kwargs.get("region_name", "us-east-1")
          placement = kwargs.get("placement", None)
          self.vpc_id = None
          self.subnet_id = kwargs.get("subnet_id")
          in_ec2_classic = not bool(self.subnet_id)
          self.key_name = kwargs.get("key_name")
          self.ebs_optimized = kwargs.get("ebs_optimized", False)
          self.source_dest_check = "true"
          self.launch_time = utc_date_and_time()
          self.ami_launch_index = kwargs.get("ami_launch_index", 0)
          self.disable_api_termination = kwargs.get("disable_api_termination", False)
          self.instance_initiated_shutdown_behavior = kwargs.get(
              "instance_initiated_shutdown_behavior", "stop"
          )
          self.sriov_net_support = "simple"
          self._spot_fleet_id = kwargs.get("spot_fleet_id", None)
          self.associate_public_ip = kwargs.get("associate_public_ip", False)
          if in_ec2_classic:
              # If we are in EC2-Classic, autoassign a public IP
              self.associate_public_ip = True
  
          amis = self.ec2_backend.describe_images(filters={"image-id": image_id})
          ami = amis[0] if amis else None
          if ami is None:
              warnings.warn(
                  "Could not find AMI with image-id:{0}, "
                  "in the near future this will "
                  "cause an error.\n"
                  "Use ec2_backend.describe_images() to "
                  "find suitable image for your test".format(image_id),
                  PendingDeprecationWarning,
              )
  
          self.platform = ami.platform if ami else None
          self.virtualization_type = ami.virtualization_type if ami else "paravirtual"
          self.architecture = ami.architecture if ami else "x86_64"
  
          # handle weird bug around user_data -- something grabs the repr(), so
          # it must be clean
          if isinstance(self.user_data, list) and len(self.user_data) > 0:
              if six.PY3 and isinstance(self.user_data[0], six.binary_type):
                  # string will have a "b" prefix -- need to get rid of it
                  self.user_data[0] = self.user_data[0].decode("utf-8")
              elif six.PY2 and isinstance(self.user_data[0], six.text_type):
                  # string will have a "u" prefix -- need to get rid of it
                  self.user_data[0] = self.user_data[0].encode("utf-8")
  
          if self.subnet_id:
              subnet = ec2_backend.get_subnet(self.subnet_id)
              self.vpc_id = subnet.vpc_id
              self._placement.zone = subnet.availability_zone
  
              if self.associate_public_ip is None:
                  # Mapping public ip hasnt been explicitly enabled or disabled
                  self.associate_public_ip = subnet.map_public_ip_on_launch == "true"
          elif placement:
              self._placement.zone = placement
          else:
              self._placement.zone = ec2_backend.region_name + "a"
  
          self.block_device_mapping = BlockDeviceMapping()
  
          self._private_ips = set()
          self.prep_nics(
              kwargs.get("nics", {}),
              private_ip=kwargs.get("private_ip"),
              associate_public_ip=self.associate_public_ip,
          )
  
      def __del__(self):
          try:
              subnet = self.ec2_backend.get_subnet(self.subnet_id)
              for ip in self._private_ips:
                  subnet.del_subnet_ip(ip)
          except Exception:
              # Its not "super" critical we clean this up, as reset will do this
              # worst case we'll get IP address exaustion... rarely
              pass
  
      def add_block_device(
          self,
          size,
          device_path,
          snapshot_id=None,
          encrypted=False,
          delete_on_termination=False,
      ):
          volume = self.ec2_backend.create_volume(
              size, self.region_name, snapshot_id, encrypted
          )
          self.ec2_backend.attach_volume(
              volume.id, self.id, device_path, delete_on_termination
          )
  
      def setup_defaults(self):
          # Default have an instance with root volume should you not wish to
          # override with attach volume cmd.
          volume = self.ec2_backend.create_volume(8, "us-east-1a")
          self.ec2_backend.attach_volume(volume.id, self.id, "/dev/sda1", True)
  
      def teardown_defaults(self):
          for device_path in list(self.block_device_mapping.keys()):
              volume = self.block_device_mapping[device_path]
              volume_id = volume.volume_id
              self.ec2_backend.detach_volume(volume_id, self.id, device_path)
              if volume.delete_on_termination:
                  self.ec2_backend.delete_volume(volume_id)
  
      @property
      def get_block_device_mapping(self):
          return self.block_device_mapping.items()
  
      @property
      def private_ip(self):
          return self.nics[0].private_ip_address
  
      @property
      def private_dns(self):
          formatted_ip = self.private_ip.replace(".", "-")
          if self.region_name == "us-east-1":
              return "ip-{0}.ec2.internal".format(formatted_ip)
          else:
              return "ip-{0}.{1}.compute.internal".format(formatted_ip, self.region_name)
  
      @property
      def public_ip(self):
          return self.nics[0].public_ip
  
      @property
      def public_dns(self):
          if self.public_ip:
              formatted_ip = self.public_ip.replace(".", "-")
              if self.region_name == "us-east-1":
                  return "ec2-{0}.compute-1.amazonaws.com".format(formatted_ip)
              else:
                  return "ec2-{0}.{1}.compute.amazonaws.com".format(
                      formatted_ip, self.region_name
                  )
  
      @staticmethod
      def cloudformation_name_type():
          return None
  
      @staticmethod
      def cloudformation_type():
          # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-instance.html
          return "AWS::EC2::Instance"
  
      @classmethod
      def create_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          properties = cloudformation_json["Properties"]
  
          ec2_backend = ec2_backends[region_name]
          security_group_ids = properties.get("SecurityGroups", [])
          group_names = [
              ec2_backend.get_security_group_from_id(group_id).name
              for group_id in security_group_ids
          ]
  
          reservation = ec2_backend.add_instances(
              image_id=properties["ImageId"],
              user_data=properties.get("UserData"),
              count=1,
              security_group_names=group_names,
              instance_type=properties.get("InstanceType", "m1.small"),
              subnet_id=properties.get("SubnetId"),
              key_name=properties.get("KeyName"),
              private_ip=properties.get("PrivateIpAddress"),
              block_device_mappings=properties.get("BlockDeviceMappings", {}),
          )
          instance = reservation.instances[0]
          for tag in properties.get("Tags", []):
              instance.add_tag(tag["Key"], tag["Value"])
          return instance
  
      @classmethod
      def delete_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          ec2_backend = ec2_backends[region_name]
          all_instances = ec2_backend.all_instances()
  
          # the resource_name for instances is the stack name, logical id, and random suffix separated
          # by hyphens.  So to lookup the instances using the 'aws:cloudformation:logical-id' tag, we need to
          # extract the logical-id from the resource_name
          logical_id = resource_name.split("-")[1]
  
          for instance in all_instances:
              instance_tags = instance.get_tags()
              for tag in instance_tags:
                  if (
                      tag["key"] == "aws:cloudformation:logical-id"
                      and tag["value"] == logical_id
                  ):
                      instance.delete(region_name)
  
      @property
      def physical_resource_id(self):
          return self.id
  
      def start(self, *args, **kwargs):
          for nic in self.nics.values():
              nic.start()
  
          self._state.name = "running"
          self._state.code = 16
  
          self._reason = ""
          self._state_reason = StateReason()
  
      def stop(self, *args, **kwargs):
          for nic in self.nics.values():
              nic.stop()
  
          self._state.name = "stopped"
          self._state.code = 80
  
          self._reason = "User initiated ({0})".format(
              datetime.utcnow().strftime("%Y-%m-%d %H:%M:%S UTC")
          )
          self._state_reason = StateReason(
              "Client.UserInitiatedShutdown: User initiated shutdown",
              "Client.UserInitiatedShutdown",
          )
  
      def delete(self, region):
          self.terminate()
  
      def terminate(self, *args, **kwargs):
          for nic in self.nics.values():
              nic.stop()
  
          self.teardown_defaults()
  
          if self._spot_fleet_id:
              spot_fleet = self.ec2_backend.get_spot_fleet_request(self._spot_fleet_id)
              for spec in spot_fleet.launch_specs:
                  if (
                      spec.instance_type == self.instance_type
                      and spec.subnet_id == self.subnet_id
                  ):
                      break
              spot_fleet.fulfilled_capacity -= spec.weighted_capacity
              spot_fleet.spot_requests = [
                  req for req in spot_fleet.spot_requests if req.instance != self
              ]
  
          self._state.name = "terminated"
          self._state.code = 48
  
          self._reason = "User initiated ({0})".format(
              datetime.utcnow().strftime("%Y-%m-%d %H:%M:%S UTC")
          )
          self._state_reason = StateReason(
              "Client.UserInitiatedShutdown: User initiated shutdown",
              "Client.UserInitiatedShutdown",
          )
  
      def reboot(self, *args, **kwargs):
          self._state.name = "running"
          self._state.code = 16
  
          self._reason = ""
          self._state_reason = StateReason()
  
      @property
      def dynamic_group_list(self):
          if self.nics:
              groups = []
              for nic in self.nics.values():
                  for group in nic.group_set:
                      groups.append(group)
              return groups
          else:
              return self.security_groups
  
      def prep_nics(self, nic_spec, private_ip=None, associate_public_ip=None):
          self.nics = {}
  
          if self.subnet_id:
              subnet = self.ec2_backend.get_subnet(self.subnet_id)
              if not private_ip:
                  private_ip = subnet.get_available_subnet_ip(instance=self)
              else:
                  subnet.request_ip(private_ip, instance=self)
  
              self._private_ips.add(private_ip)
          elif private_ip is None:
              # Preserve old behaviour if in EC2-Classic mode
              private_ip = random_private_ip()
  
          # Primary NIC defaults
          primary_nic = {
              "SubnetId": self.subnet_id,
              "PrivateIpAddress": private_ip,
              "AssociatePublicIpAddress": associate_public_ip,
          }
          primary_nic = dict((k, v) for k, v in primary_nic.items() if v)
  
          # If empty NIC spec but primary NIC values provided, create NIC from
          # them.
          if primary_nic and not nic_spec:
              nic_spec[0] = primary_nic
              nic_spec[0]["DeviceIndex"] = 0
  
          # Flesh out data structures and associations
          for nic in nic_spec.values():
              device_index = int(nic.get("DeviceIndex"))
  
              nic_id = nic.get("NetworkInterfaceId")
              if nic_id:
                  # If existing NIC found, use it.
                  use_nic = self.ec2_backend.get_network_interface(nic_id)
                  use_nic.device_index = device_index
                  use_nic.public_ip_auto_assign = False
  
              else:
                  # If primary NIC values provided, use them for the primary NIC.
                  if device_index == 0 and primary_nic:
                      nic.update(primary_nic)
  
                  if "SubnetId" in nic:
                      subnet = self.ec2_backend.get_subnet(nic["SubnetId"])
                  else:
                      # Get default Subnet
                      subnet = [
                          subnet
                          for subnet in self.ec2_backend.get_all_subnets(
                              filters={"availabilityZone": self._placement.zone}
                          )
                          if subnet.default_for_az
                      ][0]
  
                  group_id = nic.get("SecurityGroupId")
                  group_ids = [group_id] if group_id else []
  
                  use_nic = self.ec2_backend.create_network_interface(
                      subnet,
                      nic.get("PrivateIpAddress"),
                      device_index=device_index,
                      public_ip_auto_assign=nic.get("AssociatePublicIpAddress", False),
                      group_ids=group_ids,
                  )
  
              self.attach_eni(use_nic, device_index)
  
      def attach_eni(self, eni, device_index):
          device_index = int(device_index)
          self.nics[device_index] = eni
  
          # This is used upon associate/disassociate public IP.
          eni.instance = self
          eni.attachment_id = random_eni_attach_id()
          eni.device_index = device_index
  
          return eni.attachment_id
  
      def detach_eni(self, eni):
          self.nics.pop(eni.device_index, None)
          eni.instance = None
          eni.attachment_id = None
          eni.device_index = None
  
      def get_cfn_attribute(self, attribute_name):
          from moto.cloudformation.exceptions import UnformattedGetAttTemplateException
  
          if attribute_name == "AvailabilityZone":
              return self.placement
          elif attribute_name == "PrivateDnsName":
              return self.private_dns
          elif attribute_name == "PublicDnsName":
              return self.public_dns
          elif attribute_name == "PrivateIp":
              return self.private_ip
          elif attribute_name == "PublicIp":
              return self.public_ip
          raise UnformattedGetAttTemplateException()
  
      def applies(self, filters):
          if filters:
              applicable = False
              for f in filters:
                  acceptable_values = f["values"]
                  if f["name"] == "instance-state-name":
                      if self._state.name in acceptable_values:
                          applicable = True
                  if f["name"] == "instance-state-code":
                      if str(self._state.code) in acceptable_values:
                          applicable = True
              return applicable
          # If there are no filters, all instances are valid
          return True
  
  
  class InstanceBackend(object):
      def __init__(self):
          self.reservations = OrderedDict()
          super(InstanceBackend, self).__init__()
  
      def get_instance(self, instance_id):
          for instance in self.all_instances():
              if instance.id == instance_id:
                  return instance
          raise InvalidInstanceIdError(instance_id)
  
      def add_instances(self, image_id, count, user_data, security_group_names, **kwargs):
          new_reservation = Reservation()
          new_reservation.id = random_reservation_id()
  
          security_groups = [
              self.get_security_group_from_name(name) for name in security_group_names
          ]
          security_groups.extend(
              self.get_security_group_from_id(sg_id)
              for sg_id in kwargs.pop("security_group_ids", [])
          )
          self.reservations[new_reservation.id] = new_reservation
  
          tags = kwargs.pop("tags", {})
          instance_tags = tags.get("instance", {})
  
          for index in range(count):
              kwargs["ami_launch_index"] = index
              new_instance = Instance(
                  self, image_id, user_data, security_groups, **kwargs
              )
              new_reservation.instances.append(new_instance)
              new_instance.add_tags(instance_tags)
              if "block_device_mappings" in kwargs:
                  for block_device in kwargs["block_device_mappings"]:
                      device_name = block_device["DeviceName"]
                      volume_size = block_device["Ebs"].get("VolumeSize")
                      snapshot_id = block_device["Ebs"].get("SnapshotId")
                      encrypted = block_device["Ebs"].get("Encrypted", False)
                      delete_on_termination = block_device["Ebs"].get(
                          "DeleteOnTermination", False
                      )
                      new_instance.add_block_device(
                          volume_size,
                          device_name,
                          snapshot_id,
                          encrypted,
                          delete_on_termination,
                      )
              else:
                  new_instance.setup_defaults()
  
          return new_reservation
  
      def start_instances(self, instance_ids):
          started_instances = []
          for instance in self.get_multi_instances_by_id(instance_ids):
              instance.start()
              started_instances.append(instance)
  
          return started_instances
  
      def stop_instances(self, instance_ids):
          stopped_instances = []
          for instance in self.get_multi_instances_by_id(instance_ids):
              instance.stop()
              stopped_instances.append(instance)
  
          return stopped_instances
  
      def terminate_instances(self, instance_ids):
          terminated_instances = []
          if not instance_ids:
              raise EC2ClientError(
                  "InvalidParameterCombination", "No instances specified"
              )
          for instance in self.get_multi_instances_by_id(instance_ids):
              instance.terminate()
              terminated_instances.append(instance)
  
          return terminated_instances
  
      def reboot_instances(self, instance_ids):
          rebooted_instances = []
          for instance in self.get_multi_instances_by_id(instance_ids):
              instance.reboot()
              rebooted_instances.append(instance)
  
          return rebooted_instances
  
      def modify_instance_attribute(self, instance_id, key, value):
          instance = self.get_instance(instance_id)
          setattr(instance, key, value)
          return instance
  
      def modify_instance_security_groups(self, instance_id, new_group_id_list):
          instance = self.get_instance(instance_id)
          new_group_list = []
          for new_group_id in new_group_id_list:
              new_group_list.append(self.get_security_group_from_id(new_group_id))
          setattr(instance, "security_groups", new_group_list)
          return instance
  
      def describe_instance_attribute(self, instance_id, attribute):
          if attribute not in Instance.VALID_ATTRIBUTES:
              raise InvalidParameterValueErrorUnknownAttribute(attribute)
  
          if attribute == "groupSet":
              key = "security_groups"
          else:
              key = camelcase_to_underscores(attribute)
          instance = self.get_instance(instance_id)
          value = getattr(instance, key)
          return instance, value
  
      def describe_instance_credit_specifications(self, instance_ids):
          queried_instances = []
          for instance in self.get_multi_instances_by_id(instance_ids):
              queried_instances.append(instance)
          return queried_instances
  
      def all_instances(self, filters=None):
          instances = []
          for reservation in self.all_reservations():
              for instance in reservation.instances:
                  if instance.applies(filters):
                      instances.append(instance)
          return instances
  
      def all_running_instances(self, filters=None):
          instances = []
          for reservation in self.all_reservations():
              for instance in reservation.instances:
                  if instance.state_code == 16 and instance.applies(filters):
                      instances.append(instance)
          return instances
  
      def get_multi_instances_by_id(self, instance_ids, filters=None):
          """
          :param instance_ids: A string list with instance ids
          :return: A list with instance objects
          """
          result = []
  
          for reservation in self.all_reservations():
              for instance in reservation.instances:
                  if instance.id in instance_ids:
                      if instance.applies(filters):
                          result.append(instance)
  
          # TODO: Trim error message down to specific invalid id.
          if instance_ids and len(instance_ids) > len(result):
              raise InvalidInstanceIdError(instance_ids)
  
          return result
  
      def get_instance_by_id(self, instance_id):
          for reservation in self.all_reservations():
              for instance in reservation.instances:
                  if instance.id == instance_id:
                      return instance
  
      def get_reservations_by_instance_ids(self, instance_ids, filters=None):
          """Go through all of the reservations and filter to only return those
          associated with the given instance_ids.
          """
          reservations = []
          for reservation in self.all_reservations():
              reservation_instance_ids = [
                  instance.id for instance in reservation.instances
              ]
              matching_reservation = any(
                  instance_id in reservation_instance_ids for instance_id in instance_ids
              )
              if matching_reservation:
                  reservation.instances = [
                      instance
                      for instance in reservation.instances
                      if instance.id in instance_ids
                  ]
                  reservations.append(reservation)
          found_instance_ids = [
              instance.id
              for reservation in reservations
              for instance in reservation.instances
          ]
          if len(found_instance_ids) != len(instance_ids):
              invalid_id = list(set(instance_ids).difference(set(found_instance_ids)))[0]
              raise InvalidInstanceIdError(invalid_id)
          if filters is not None:
              reservations = filter_reservations(reservations, filters)
          return reservations
  
      def all_reservations(self, filters=None):
          reservations = [
              copy.copy(reservation) for reservation in self.reservations.values()
          ]
          if filters is not None:
              reservations = filter_reservations(reservations, filters)
          return reservations
  
  
  class KeyPair(object):
      def __init__(self, name, fingerprint, material):
          self.name = name
          self.fingerprint = fingerprint
          self.material = material
  
      def get_filter_value(self, filter_name):
          if filter_name == "key-name":
              return self.name
          elif filter_name == "fingerprint":
              return self.fingerprint
          else:
              raise FilterNotImplementedError(filter_name, "DescribeKeyPairs")
  
  
  class KeyPairBackend(object):
      def __init__(self):
          self.keypairs = {}
          super(KeyPairBackend, self).__init__()
  
      def create_key_pair(self, name):
          if name in self.keypairs:
              raise InvalidKeyPairDuplicateError(name)
          keypair = KeyPair(name, **random_key_pair())
          self.keypairs[name] = keypair
          return keypair
  
      def delete_key_pair(self, name):
          if name in self.keypairs:
              self.keypairs.pop(name)
          return True
  
      def describe_key_pairs(self, key_names=None, filters=None):
          results = []
          if key_names:
              results = [
                  keypair
                  for keypair in self.keypairs.values()
                  if keypair.name in key_names
              ]
              if len(key_names) > len(results):
                  unknown_keys = set(key_names) - set(results)
                  raise InvalidKeyPairNameError(unknown_keys)
          else:
              results = self.keypairs.values()
  
          if filters:
              return generic_filter(filters, results)
          else:
              return results
  
      def import_key_pair(self, key_name, public_key_material):
          if key_name in self.keypairs:
              raise InvalidKeyPairDuplicateError(key_name)
  
          try:
              rsa_public_key = rsa_public_key_parse(public_key_material)
          except ValueError:
              raise InvalidKeyPairFormatError()
  
          fingerprint = rsa_public_key_fingerprint(rsa_public_key)
          keypair = KeyPair(
              key_name, material=public_key_material, fingerprint=fingerprint
          )
          self.keypairs[key_name] = keypair
          return keypair
  
  
  class TagBackend(object):
      VALID_TAG_FILTERS = ["key", "resource-id", "resource-type", "value"]
  
      VALID_TAG_RESOURCE_FILTER_TYPES = [
          "customer-gateway",
          "dhcp-options",
          "image",
          "instance",
          "internet-gateway",
          "network-acl",
          "network-interface",
          "reserved-instances",
          "route-table",
          "security-group",
          "snapshot",
          "spot-instances-request",
          "subnet",
          "volume",
          "vpc",
          "vpc-flow-log",
          "vpc-peering-connection" "vpn-connection",
          "vpn-gateway",
      ]
  
      def __init__(self):
          self.tags = defaultdict(dict)
          super(TagBackend, self).__init__()
  
      def create_tags(self, resource_ids, tags):
          if None in set([tags[tag] for tag in tags]):
              raise InvalidParameterValueErrorTagNull()
          for resource_id in resource_ids:
              if resource_id in self.tags:
                  if (
                      len(self.tags[resource_id])
                      + len([tag for tag in tags if not tag.startswith("aws:")])
                      > 50
                  ):
                      raise TagLimitExceeded()
              elif len([tag for tag in tags if not tag.startswith("aws:")]) > 50:
                  raise TagLimitExceeded()
          for resource_id in resource_ids:
              for tag in tags:
                  self.tags[resource_id][tag] = tags[tag]
          return True
  
      def delete_tags(self, resource_ids, tags):
          for resource_id in resource_ids:
              for tag in tags:
                  if tag in self.tags[resource_id]:
                      if tags[tag] is None:
                          self.tags[resource_id].pop(tag)
                      elif tags[tag] == self.tags[resource_id][tag]:
                          self.tags[resource_id].pop(tag)
          return True
  
      def describe_tags(self, filters=None):
          import re
  
          results = []
          key_filters = []
          resource_id_filters = []
          resource_type_filters = []
          value_filters = []
          if filters is not None:
              for tag_filter in filters:
                  if tag_filter in self.VALID_TAG_FILTERS:
                      if tag_filter == "key":
                          for value in filters[tag_filter]:
                              key_filters.append(
                                  re.compile(simple_aws_filter_to_re(value))
                              )
                      if tag_filter == "resource-id":
                          for value in filters[tag_filter]:
                              resource_id_filters.append(
                                  re.compile(simple_aws_filter_to_re(value))
                              )
                      if tag_filter == "resource-type":
                          for value in filters[tag_filter]:
                              resource_type_filters.append(value)
                      if tag_filter == "value":
                          for value in filters[tag_filter]:
                              value_filters.append(
                                  re.compile(simple_aws_filter_to_re(value))
                              )
          for resource_id, tags in self.tags.items():
              for key, value in tags.items():
                  add_result = False
                  if filters is None:
                      add_result = True
                  else:
                      key_pass = False
                      id_pass = False
                      type_pass = False
                      value_pass = False
                      if key_filters:
                          for pattern in key_filters:
                              if pattern.match(key) is not None:
                                  key_pass = True
                      else:
                          key_pass = True
                      if resource_id_filters:
                          for pattern in resource_id_filters:
                              if pattern.match(resource_id) is not None:
                                  id_pass = True
                      else:
                          id_pass = True
                      if resource_type_filters:
                          for resource_type in resource_type_filters:
                              if (
                                  EC2_PREFIX_TO_RESOURCE[get_prefix(resource_id)]
                                  == resource_type
                              ):
                                  type_pass = True
                      else:
                          type_pass = True
                      if value_filters:
                          for pattern in value_filters:
                              if pattern.match(value) is not None:
                                  value_pass = True
                      else:
                          value_pass = True
                      if key_pass and id_pass and type_pass and value_pass:
                          add_result = True
                          # If we're not filtering, or we are filtering and this
                  if add_result:
                      result = {
                          "resource_id": resource_id,
                          "key": key,
                          "value": value,
                          "resource_type": EC2_PREFIX_TO_RESOURCE[
                              get_prefix(resource_id)
                          ],
                      }
                      results.append(result)
          return results
  
  
  class Ami(TaggedEC2Resource):
      def __init__(
          self,
          ec2_backend,
          ami_id,
          instance=None,
          source_ami=None,
          name=None,
          description=None,
          owner_id=OWNER_ID,
          public=False,
          virtualization_type=None,
          architecture=None,
          state="available",
          creation_date=None,
          platform=None,
          image_type="machine",
          image_location=None,
          hypervisor=None,
          root_device_type="standard",
          root_device_name="/dev/sda1",
          sriov="simple",
          region_name="us-east-1a",
      ):
          self.ec2_backend = ec2_backend
          self.id = ami_id
          self.state = state
          self.name = name
          self.image_type = image_type
          self.image_location = image_location
          self.owner_id = owner_id
          self.description = description
          self.virtualization_type = virtualization_type
          self.architecture = architecture
          self.kernel_id = None
          self.platform = platform
          self.hypervisor = hypervisor
          self.root_device_name = root_device_name
          self.root_device_type = root_device_type
          self.sriov = sriov
          self.creation_date = (
              utc_date_and_time() if creation_date is None else creation_date
          )
  
          if instance:
              self.instance = instance
              self.instance_id = instance.id
              self.virtualization_type = instance.virtualization_type
              self.architecture = instance.architecture
              self.kernel_id = instance.kernel
              self.platform = instance.platform
  
          elif source_ami:
              """
              http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/CopyingAMIs.html
              "We don't copy launch permissions, user-defined tags, or Amazon S3 bucket permissions from the source AMI to the new AMI."
              ~ 2014.09.29
              """
              self.virtualization_type = source_ami.virtualization_type
              self.architecture = source_ami.architecture
              self.kernel_id = source_ami.kernel_id
              self.platform = source_ami.platform
              if not name:
                  self.name = source_ami.name
              if not description:
                  self.description = source_ami.description
  
          self.launch_permission_groups = set()
          self.launch_permission_users = set()
  
          if public:
              self.launch_permission_groups.add("all")
  
          # AWS auto-creates these, we should reflect the same.
          volume = self.ec2_backend.create_volume(15, region_name)
          self.ebs_snapshot = self.ec2_backend.create_snapshot(
              volume.id, "Auto-created snapshot for AMI %s" % self.id, owner_id
          )
          self.ec2_backend.delete_volume(volume.id)
  
      @property
      def is_public(self):
          return "all" in self.launch_permission_groups
  
      @property
      def is_public_string(self):
          return str(self.is_public).lower()
  
      def get_filter_value(self, filter_name):
          if filter_name == "virtualization-type":
              return self.virtualization_type
          elif filter_name == "kernel-id":
              return self.kernel_id
          elif filter_name in ["architecture", "platform"]:
              return getattr(self, filter_name)
          elif filter_name == "image-id":
              return self.id
          elif filter_name == "is-public":
              return self.is_public_string
          elif filter_name == "state":
              return self.state
          elif filter_name == "name":
              return self.name
          elif filter_name == "owner-id":
              return self.owner_id
          else:
              return super(Ami, self).get_filter_value(filter_name, "DescribeImages")
  
  
  class AmiBackend(object):
      AMI_REGEX = re.compile("ami-[a-z0-9]+")
  
      def __init__(self):
          self.amis = {}
  
          self._load_amis()
  
          super(AmiBackend, self).__init__()
  
      def _load_amis(self):
          for ami in AMIS:
              ami_id = ami["ami_id"]
              self.amis[ami_id] = Ami(self, **ami)
  
      def create_image(self, instance_id, name=None, description=None, context=None):
          # TODO: check that instance exists and pull info from it.
          ami_id = random_ami_id()
          instance = self.get_instance(instance_id)
  
          ami = Ami(
              self,
              ami_id,
              instance=instance,
              source_ami=None,
              name=name,
              description=description,
              owner_id=OWNER_ID,
          )
          self.amis[ami_id] = ami
          return ami
  
      def copy_image(self, source_image_id, source_region, name=None, description=None):
          source_ami = ec2_backends[source_region].describe_images(
              ami_ids=[source_image_id]
          )[0]
          ami_id = random_ami_id()
          ami = Ami(
              self,
              ami_id,
              instance=None,
              source_ami=source_ami,
              name=name,
              description=description,
          )
          self.amis[ami_id] = ami
          return ami
  
      def describe_images(
          self, ami_ids=(), filters=None, exec_users=None, owners=None, context=None
      ):
          images = self.amis.values()
  
          if len(ami_ids):
              # boto3 seems to default to just searching based on ami ids if that parameter is passed
              # and if no images are found, it raises an errors
              malformed_ami_ids = [
                  ami_id for ami_id in ami_ids if not ami_id.startswith("ami-")
              ]
              if malformed_ami_ids:
                  raise MalformedAMIIdError(malformed_ami_ids)
  
              images = [ami for ami in images if ami.id in ami_ids]
              if len(images) == 0:
                  raise InvalidAMIIdError(ami_ids)
          else:
              # Limit images by launch permissions
              if exec_users:
                  tmp_images = []
                  for ami in images:
                      for user_id in exec_users:
                          if user_id in ami.launch_permission_users:
                              tmp_images.append(ami)
                  images = tmp_images
  
              # Limit by owner ids
              if owners:
                  # support filtering by Owners=['self']
                  owners = list(map(lambda o: OWNER_ID if o == "self" else o, owners,))
                  images = [ami for ami in images if ami.owner_id in owners]
  
              # Generic filters
              if filters:
                  return generic_filter(filters, images)
  
          return images
  
      def deregister_image(self, ami_id):
          if ami_id in self.amis:
              self.amis.pop(ami_id)
              return True
          raise InvalidAMIIdError(ami_id)
  
      def get_launch_permission_groups(self, ami_id):
          ami = self.describe_images(ami_ids=[ami_id])[0]
          return ami.launch_permission_groups
  
      def get_launch_permission_users(self, ami_id):
          ami = self.describe_images(ami_ids=[ami_id])[0]
          return ami.launch_permission_users
  
      def validate_permission_targets(self, user_ids=None, group=None):
          # If anything is invalid, nothing is added. (No partial success.)
          if user_ids:
              """
              AWS docs:
                "The AWS account ID is a 12-digit number, such as 123456789012, that you use to construct Amazon Resource Names (ARNs)."
                http://docs.aws.amazon.com/general/latest/gr/acct-identifiers.html
              """
              for user_id in user_ids:
                  if len(user_id) != 12 or not user_id.isdigit():
                      raise InvalidAMIAttributeItemValueError("userId", user_id)
  
          if group and group != "all":
              raise InvalidAMIAttributeItemValueError("UserGroup", group)
  
      def add_launch_permission(self, ami_id, user_ids=None, group=None):
          ami = self.describe_images(ami_ids=[ami_id])[0]
          self.validate_permission_targets(user_ids=user_ids, group=group)
  
          if user_ids:
              for user_id in user_ids:
                  ami.launch_permission_users.add(user_id)
  
          if group:
              ami.launch_permission_groups.add(group)
  
          return True
  
      def register_image(self, name=None, description=None):
          ami_id = random_ami_id()
          ami = Ami(
              self,
              ami_id,
              instance=None,
              source_ami=None,
              name=name,
              description=description,
          )
          self.amis[ami_id] = ami
          return ami
  
      def remove_launch_permission(self, ami_id, user_ids=None, group=None):
          ami = self.describe_images(ami_ids=[ami_id])[0]
          self.validate_permission_targets(user_ids=user_ids, group=group)
  
          if user_ids:
              for user_id in user_ids:
                  ami.launch_permission_users.discard(user_id)
  
          if group:
              ami.launch_permission_groups.discard(group)
  
          return True
  
  
  class Region(object):
      def __init__(self, name, endpoint, opt_in_status):
          self.name = name
          self.endpoint = endpoint
          self.opt_in_status = opt_in_status
  
  
  class Zone(object):
      def __init__(self, name, region_name, zone_id):
          self.name = name
          self.region_name = region_name
          self.zone_id = zone_id
  
  
  class RegionsAndZonesBackend(object):
      regions_opt_in_not_required = [
          "af-south-1",
          "ap-northeast-1",
          "ap-northeast-2",
          "ap-northeast-3",
          "ap-south-1",
          "ap-southeast-1",
          "ap-southeast-2",
          "ca-central-1",
          "eu-central-1",
          "eu-north-1",
          "eu-south-1",
          "eu-west-1",
          "eu-west-2",
          "eu-west-3",
          "sa-east-1",
          "us-east-1",
          "us-east-2",
          "us-west-1",
          "us-west-2",
      ]
  
      regions = []
      for region in Session().get_available_regions("ec2"):
          if region in regions_opt_in_not_required:
              regions.append(
                  Region(
                      region, "ec2.{}.amazonaws.com".format(region), "opt-in-not-required"
                  )
              )
          else:
              regions.append(
                  Region(region, "ec2.{}.amazonaws.com".format(region), "not-opted-in")
              )
      for region in Session().get_available_regions("ec2", partition_name="aws-us-gov"):
          regions.append(
              Region(region, "ec2.{}.amazonaws.com".format(region), "opt-in-not-required")
          )
      for region in Session().get_available_regions("ec2", partition_name="aws-cn"):
          regions.append(
              Region(
                  region, "ec2.{}.amazonaws.com.cn".format(region), "opt-in-not-required"
              )
          )
  
      zones = {
          "af-south-1": [
              Zone(region_name="af-south-1", name="af-south-1a", zone_id="afs1-az1"),
              Zone(region_name="af-south-1", name="af-south-1b", zone_id="afs1-az2"),
              Zone(region_name="af-south-1", name="af-south-1c", zone_id="afs1-az3"),
          ],
          "ap-south-1": [
              Zone(region_name="ap-south-1", name="ap-south-1a", zone_id="aps1-az1"),
              Zone(region_name="ap-south-1", name="ap-south-1b", zone_id="aps1-az3"),
          ],
          "eu-west-3": [
              Zone(region_name="eu-west-3", name="eu-west-3a", zone_id="euw3-az1"),
              Zone(region_name="eu-west-3", name="eu-west-3b", zone_id="euw3-az2"),
              Zone(region_name="eu-west-3", name="eu-west-3c", zone_id="euw3-az3"),
          ],
          "eu-north-1": [
              Zone(region_name="eu-north-1", name="eu-north-1a", zone_id="eun1-az1"),
              Zone(region_name="eu-north-1", name="eu-north-1b", zone_id="eun1-az2"),
              Zone(region_name="eu-north-1", name="eu-north-1c", zone_id="eun1-az3"),
          ],
          "eu-west-2": [
              Zone(region_name="eu-west-2", name="eu-west-2a", zone_id="euw2-az2"),
              Zone(region_name="eu-west-2", name="eu-west-2b", zone_id="euw2-az3"),
              Zone(region_name="eu-west-2", name="eu-west-2c", zone_id="euw2-az1"),
          ],
          "eu-west-1": [
              Zone(region_name="eu-west-1", name="eu-west-1a", zone_id="euw1-az3"),
              Zone(region_name="eu-west-1", name="eu-west-1b", zone_id="euw1-az1"),
              Zone(region_name="eu-west-1", name="eu-west-1c", zone_id="euw1-az2"),
          ],
          "ap-northeast-3": [
              Zone(
                  region_name="ap-northeast-3",
                  name="ap-northeast-2a",
                  zone_id="apne3-az1",
              )
          ],
          "ap-northeast-2": [
              Zone(
                  region_name="ap-northeast-2",
                  name="ap-northeast-2a",
                  zone_id="apne2-az1",
              ),
              Zone(
                  region_name="ap-northeast-2",
                  name="ap-northeast-2c",
                  zone_id="apne2-az3",
              ),
          ],
          "ap-northeast-1": [
              Zone(
                  region_name="ap-northeast-1",
                  name="ap-northeast-1a",
                  zone_id="apne1-az4",
              ),
              Zone(
                  region_name="ap-northeast-1",
                  name="ap-northeast-1c",
                  zone_id="apne1-az1",
              ),
              Zone(
                  region_name="ap-northeast-1",
                  name="ap-northeast-1d",
                  zone_id="apne1-az2",
              ),
          ],
          "ap-east-1": [
              Zone(region_name="ap-east-1", name="ap-east-1a", zone_id="ape1-az1"),
              Zone(region_name="ap-east-1", name="ap-east-1b", zone_id="ape1-az2"),
              Zone(region_name="ap-east-1", name="ap-east-1c", zone_id="ape1-az3"),
          ],
          "sa-east-1": [
              Zone(region_name="sa-east-1", name="sa-east-1a", zone_id="sae1-az1"),
              Zone(region_name="sa-east-1", name="sa-east-1c", zone_id="sae1-az3"),
          ],
          "ca-central-1": [
              Zone(region_name="ca-central-1", name="ca-central-1a", zone_id="cac1-az1"),
              Zone(region_name="ca-central-1", name="ca-central-1b", zone_id="cac1-az2"),
          ],
          "ap-southeast-1": [
              Zone(
                  region_name="ap-southeast-1",
                  name="ap-southeast-1a",
                  zone_id="apse1-az1",
              ),
              Zone(
                  region_name="ap-southeast-1",
                  name="ap-southeast-1b",
                  zone_id="apse1-az2",
              ),
              Zone(
                  region_name="ap-southeast-1",
                  name="ap-southeast-1c",
                  zone_id="apse1-az3",
              ),
          ],
          "ap-southeast-2": [
              Zone(
                  region_name="ap-southeast-2",
                  name="ap-southeast-2a",
                  zone_id="apse2-az1",
              ),
              Zone(
                  region_name="ap-southeast-2",
                  name="ap-southeast-2b",
                  zone_id="apse2-az3",
              ),
              Zone(
                  region_name="ap-southeast-2",
                  name="ap-southeast-2c",
                  zone_id="apse2-az2",
              ),
          ],
          "eu-central-1": [
              Zone(region_name="eu-central-1", name="eu-central-1a", zone_id="euc1-az2"),
              Zone(region_name="eu-central-1", name="eu-central-1b", zone_id="euc1-az3"),
              Zone(region_name="eu-central-1", name="eu-central-1c", zone_id="euc1-az1"),
          ],
          "eu-south-1": [
              Zone(region_name="eu-south-1", name="eu-south-1a", zone_id="eus1-az1"),
              Zone(region_name="eu-south-1", name="eu-south-1b", zone_id="eus1-az2"),
              Zone(region_name="eu-south-1", name="eu-south-1c", zone_id="eus1-az3"),
          ],
          "us-east-1": [
              Zone(region_name="us-east-1", name="us-east-1a", zone_id="use1-az6"),
              Zone(region_name="us-east-1", name="us-east-1b", zone_id="use1-az1"),
              Zone(region_name="us-east-1", name="us-east-1c", zone_id="use1-az2"),
              Zone(region_name="us-east-1", name="us-east-1d", zone_id="use1-az4"),
              Zone(region_name="us-east-1", name="us-east-1e", zone_id="use1-az3"),
              Zone(region_name="us-east-1", name="us-east-1f", zone_id="use1-az5"),
          ],
          "us-east-2": [
              Zone(region_name="us-east-2", name="us-east-2a", zone_id="use2-az1"),
              Zone(region_name="us-east-2", name="us-east-2b", zone_id="use2-az2"),
              Zone(region_name="us-east-2", name="us-east-2c", zone_id="use2-az3"),
          ],
          "us-west-1": [
              Zone(region_name="us-west-1", name="us-west-1a", zone_id="usw1-az3"),
              Zone(region_name="us-west-1", name="us-west-1b", zone_id="usw1-az1"),
          ],
          "us-west-2": [
              Zone(region_name="us-west-2", name="us-west-2a", zone_id="usw2-az2"),
              Zone(region_name="us-west-2", name="us-west-2b", zone_id="usw2-az1"),
              Zone(region_name="us-west-2", name="us-west-2c", zone_id="usw2-az3"),
          ],
          "me-south-1": [
              Zone(region_name="me-south-1", name="me-south-1a", zone_id="mes1-az1"),
              Zone(region_name="me-south-1", name="me-south-1b", zone_id="mes1-az2"),
              Zone(region_name="me-south-1", name="me-south-1c", zone_id="mes1-az3"),
          ],
          "cn-north-1": [
              Zone(region_name="cn-north-1", name="cn-north-1a", zone_id="cnn1-az1"),
              Zone(region_name="cn-north-1", name="cn-north-1b", zone_id="cnn1-az2"),
          ],
          "cn-northwest-1": [
              Zone(
                  region_name="cn-northwest-1",
                  name="cn-northwest-1a",
                  zone_id="cnnw1-az1",
              ),
              Zone(
                  region_name="cn-northwest-1",
                  name="cn-northwest-1b",
                  zone_id="cnnw1-az2",
              ),
              Zone(
                  region_name="cn-northwest-1",
                  name="cn-northwest-1c",
                  zone_id="cnnw1-az3",
              ),
          ],
          "us-gov-west-1": [
              Zone(
                  region_name="us-gov-west-1", name="us-gov-west-1a", zone_id="usgw1-az1"
              ),
              Zone(
                  region_name="us-gov-west-1", name="us-gov-west-1b", zone_id="usgw1-az2"
              ),
              Zone(
                  region_name="us-gov-west-1", name="us-gov-west-1c", zone_id="usgw1-az3"
              ),
          ],
          "us-gov-east-1": [
              Zone(
                  region_name="us-gov-east-1", name="us-gov-east-1a", zone_id="usge1-az1"
              ),
              Zone(
                  region_name="us-gov-east-1", name="us-gov-east-1b", zone_id="usge1-az2"
              ),
              Zone(
                  region_name="us-gov-east-1", name="us-gov-east-1c", zone_id="usge1-az3"
              ),
          ],
      }
  
      def describe_regions(self, region_names=[]):
          if len(region_names) == 0:
              return self.regions
          ret = []
          for name in region_names:
              for region in self.regions:
                  if region.name == name:
                      ret.append(region)
          return ret
  
      def describe_availability_zones(self):
          return self.zones[self.region_name]
  
      def get_zone_by_name(self, name):
          for zone in self.zones[self.region_name]:
              if zone.name == name:
                  return zone
  
  
  class SecurityRule(object):
      def __init__(self, ip_protocol, from_port, to_port, ip_ranges, source_groups):
          self.ip_protocol = ip_protocol
          self.ip_ranges = ip_ranges or []
          self.source_groups = source_groups
  
          if ip_protocol != "-1":
              self.from_port = from_port
              self.to_port = to_port
  
      def __eq__(self, other):
          if self.ip_protocol != other.ip_protocol:
              return False
          if self.ip_ranges != other.ip_ranges:
              return False
          if self.source_groups != other.source_groups:
              return False
          if self.ip_protocol != "-1":
              if self.from_port != other.from_port:
                  return False
              if self.to_port != other.to_port:
                  return False
  
          return True
  
  
  class SecurityGroup(TaggedEC2Resource, CloudFormationModel):
      def __init__(self, ec2_backend, group_id, name, description, vpc_id=None):
          self.ec2_backend = ec2_backend
          self.id = group_id
          self.name = name
          self.description = description
          self.ingress_rules = []
          self.egress_rules = [
              SecurityRule("-1", None, None, [{"CidrIp": "0.0.0.0/0"}], [])
          ]
          self.enis = {}
          self.vpc_id = vpc_id
          self.owner_id = OWNER_ID
  
          # Append default IPv6 egress rule for VPCs with IPv6 support
          if vpc_id:
              vpc = self.ec2_backend.vpcs.get(vpc_id)
              if vpc and len(vpc.get_cidr_block_association_set(ipv6=True)) > 0:
                  self.egress_rules.append(SecurityRule("-1", None, None, [], []))
  
      @staticmethod
      def cloudformation_name_type():
          return "GroupName"
  
      @staticmethod
      def cloudformation_type():
          # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-securitygroup.html
          return "AWS::EC2::SecurityGroup"
  
      @classmethod
      def create_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          properties = cloudformation_json["Properties"]
  
          ec2_backend = ec2_backends[region_name]
          vpc_id = properties.get("VpcId")
          security_group = ec2_backend.create_security_group(
              name=resource_name,
              description=properties.get("GroupDescription"),
              vpc_id=vpc_id,
          )
  
          for tag in properties.get("Tags", []):
              tag_key = tag["Key"]
              tag_value = tag["Value"]
              security_group.add_tag(tag_key, tag_value)
  
          for ingress_rule in properties.get("SecurityGroupIngress", []):
              source_group_id = ingress_rule.get("SourceSecurityGroupId")
  
              ec2_backend.authorize_security_group_ingress(
                  group_name_or_id=security_group.id,
                  ip_protocol=ingress_rule["IpProtocol"],
                  from_port=ingress_rule["FromPort"],
                  to_port=ingress_rule["ToPort"],
                  ip_ranges=ingress_rule.get("CidrIp"),
                  source_group_ids=[source_group_id],
                  vpc_id=vpc_id,
              )
  
          return security_group
  
      @classmethod
      def update_from_cloudformation_json(
          cls, original_resource, new_resource_name, cloudformation_json, region_name
      ):
          cls._delete_security_group_given_vpc_id(
              original_resource.name, original_resource.vpc_id, region_name
          )
          return cls.create_from_cloudformation_json(
              new_resource_name, cloudformation_json, region_name
          )
  
      @classmethod
      def delete_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          properties = cloudformation_json["Properties"]
          vpc_id = properties.get("VpcId")
          cls._delete_security_group_given_vpc_id(resource_name, vpc_id, region_name)
  
      @classmethod
      def _delete_security_group_given_vpc_id(cls, resource_name, vpc_id, region_name):
          ec2_backend = ec2_backends[region_name]
          security_group = ec2_backend.get_security_group_from_name(resource_name, vpc_id)
          if security_group:
              security_group.delete(region_name)
  
      def delete(self, region_name):
          """ Not exposed as part of the ELB API - used for CloudFormation. """
          self.ec2_backend.delete_security_group(group_id=self.id)
  
      @property
      def physical_resource_id(self):
          return self.id
  
      def matches_filter(self, key, filter_value):
          def to_attr(filter_name):
              attr = None
  
              if filter_name == "group-name":
                  attr = "name"
              elif filter_name == "group-id":
                  attr = "id"
              elif filter_name == "vpc-id":
                  attr = "vpc_id"
              else:
                  attr = filter_name.replace("-", "_")
  
              return attr
  
          if key.startswith("ip-permission"):
              match = re.search(r"ip-permission.(*)", key)
              ingress_attr = to_attr(match.groups()[0])
  
              for ingress in self.ingress_rules:
                  if getattr(ingress, ingress_attr) in filter_value:
                      return True
          elif is_tag_filter(key):
              tag_value = self.get_filter_value(key)
              if isinstance(filter_value, list):
                  return tag_filter_matches(self, key, filter_value)
              return tag_value in filter_value
          else:
              attr_name = to_attr(key)
              return getattr(self, attr_name) in filter_value
  
          return False
  
      def matches_filters(self, filters):
          for key, value in filters.items():
              if not self.matches_filter(key, value):
                  return False
          return True
  
      def get_cfn_attribute(self, attribute_name):
          from moto.cloudformation.exceptions import UnformattedGetAttTemplateException
  
          if attribute_name == "GroupId":
              return self.id
          raise UnformattedGetAttTemplateException()
  
      def add_ingress_rule(self, rule):
          if rule in self.ingress_rules:
              raise InvalidPermissionDuplicateError()
          else:
              self.ingress_rules.append(rule)
  
      def add_egress_rule(self, rule):
          self.egress_rules.append(rule)
  
      def get_number_of_ingress_rules(self):
          return sum(
              len(rule.ip_ranges) + len(rule.source_groups) for rule in self.ingress_rules
          )
  
      def get_number_of_egress_rules(self):
          return sum(
              len(rule.ip_ranges) + len(rule.source_groups) for rule in self.egress_rules
          )
  
  
  class SecurityGroupBackend(object):
      def __init__(self):
          # the key in the dict group is the vpc_id or None (non-vpc)
          self.groups = defaultdict(dict)
  
          # Create the default security group
          self.create_security_group("default", "default group")
  
          super(SecurityGroupBackend, self).__init__()
  
      def create_security_group(self, name, description, vpc_id=None, force=False):
          if not description:
              raise MissingParameterError("GroupDescription")
  
          group_id = random_security_group_id()
          if not force:
              existing_group = self.get_security_group_from_name(name, vpc_id)
              if existing_group:
                  raise InvalidSecurityGroupDuplicateError(name)
          group = SecurityGroup(self, group_id, name, description, vpc_id=vpc_id)
  
          self.groups[vpc_id][group_id] = group
          return group
  
      def describe_security_groups(self, group_ids=None, groupnames=None, filters=None):
          matches = itertools.chain(*[x.values() for x in self.groups.values()])
          if group_ids:
              matches = [grp for grp in matches if grp.id in group_ids]
              if len(group_ids) > len(matches):
                  unknown_ids = set(group_ids) - set(matches)
                  raise InvalidSecurityGroupNotFoundError(unknown_ids)
          if groupnames:
              matches = [grp for grp in matches if grp.name in groupnames]
              if len(groupnames) > len(matches):
                  unknown_names = set(groupnames) - set(matches)
                  raise InvalidSecurityGroupNotFoundError(unknown_names)
          if filters:
              matches = [grp for grp in matches if grp.matches_filters(filters)]
  
          return matches
  
      def _delete_security_group(self, vpc_id, group_id):
          if self.groups[vpc_id][group_id].enis:
              raise DependencyViolationError(
                  "{0} is being utilized by {1}".format(group_id, "ENIs")
              )
          return self.groups[vpc_id].pop(group_id)
  
      def delete_security_group(self, name=None, group_id=None):
          if group_id:
              # loop over all the SGs, find the right one
              for vpc_id, groups in self.groups.items():
                  if group_id in groups:
                      return self._delete_security_group(vpc_id, group_id)
              raise InvalidSecurityGroupNotFoundError(group_id)
          elif name:
              # Group Name.  Has to be in standard EC2, VPC needs to be
              # identified by group_id
              group = self.get_security_group_from_name(name)
              if group:
                  return self._delete_security_group(None, group.id)
              raise InvalidSecurityGroupNotFoundError(name)
  
      def get_security_group_from_id(self, group_id):
          # 2 levels of chaining necessary since it's a complex structure
          all_groups = itertools.chain.from_iterable(
              [x.values() for x in self.groups.values()]
          )
          for group in all_groups:
              if group.id == group_id:
                  return group
  
      def get_security_group_from_name(self, name, vpc_id=None):
          for group_id, group in self.groups[vpc_id].items():
              if group.name == name:
                  return group
  
      def get_security_group_by_name_or_id(self, group_name_or_id, vpc_id):
          # try searching by id, fallbacks to name search
          group = self.get_security_group_from_id(group_name_or_id)
          if group is None:
              group = self.get_security_group_from_name(group_name_or_id, vpc_id)
          return group
  
      def authorize_security_group_ingress(
          self,
          group_name_or_id,
          ip_protocol,
          from_port,
          to_port,
          ip_ranges,
          source_group_names=None,
          source_group_ids=None,
          vpc_id=None,
      ):
          group = self.get_security_group_by_name_or_id(group_name_or_id, vpc_id)
          if ip_ranges:
              if isinstance(ip_ranges, str) or (
                  six.PY2 and isinstance(ip_ranges, unicode)  # noqa
              ):
                  ip_ranges = [{"CidrIp": str(ip_ranges)}]
              elif not isinstance(ip_ranges, list):
                  ip_ranges = [json.loads(ip_ranges)]
          if ip_ranges:
              for cidr in ip_ranges:
                  if not is_valid_cidr(cidr["CidrIp"]):
                      raise InvalidCIDRSubnetError(cidr=cidr)
  
          self._verify_group_will_respect_rule_count_limit(
              group,
              group.get_number_of_ingress_rules(),
              ip_ranges,
              source_group_names,
              source_group_ids,
          )
  
          source_group_names = source_group_names if source_group_names else []
          source_group_ids = source_group_ids if source_group_ids else []
  
          source_groups = []
          for source_group_name in source_group_names:
              source_group = self.get_security_group_from_name(source_group_name, vpc_id)
              if source_group:
                  source_groups.append(source_group)
  
          # for VPCs
          for source_group_id in source_group_ids:
              source_group = self.get_security_group_from_id(source_group_id)
              if source_group:
                  source_groups.append(source_group)
  
          security_rule = SecurityRule(
              ip_protocol, from_port, to_port, ip_ranges, source_groups
          )
          group.add_ingress_rule(security_rule)
  
      def revoke_security_group_ingress(
          self,
          group_name_or_id,
          ip_protocol,
          from_port,
          to_port,
          ip_ranges,
          source_group_names=None,
          source_group_ids=None,
          vpc_id=None,
      ):
  
          group = self.get_security_group_by_name_or_id(group_name_or_id, vpc_id)
  
          source_groups = []
          for source_group_name in source_group_names:
              source_group = self.get_security_group_from_name(source_group_name, vpc_id)
              if source_group:
                  source_groups.append(source_group)
  
          for source_group_id in source_group_ids:
              source_group = self.get_security_group_from_id(source_group_id)
              if source_group:
                  source_groups.append(source_group)
  
          security_rule = SecurityRule(
              ip_protocol, from_port, to_port, ip_ranges, source_groups
          )
          if security_rule in group.ingress_rules:
              group.ingress_rules.remove(security_rule)
              return security_rule
          raise InvalidPermissionNotFoundError()
  
      def authorize_security_group_egress(
          self,
          group_name_or_id,
          ip_protocol,
          from_port,
          to_port,
          ip_ranges,
          source_group_names=None,
          source_group_ids=None,
          vpc_id=None,
      ):
  
          group = self.get_security_group_by_name_or_id(group_name_or_id, vpc_id)
          if ip_ranges and not isinstance(ip_ranges, list):
  
              if isinstance(ip_ranges, str) and "CidrIp" not in ip_ranges:
                  ip_ranges = [{"CidrIp": ip_ranges}]
              else:
                  ip_ranges = [json.loads(ip_ranges)]
          if ip_ranges:
              for cidr in ip_ranges:
                  if not is_valid_cidr(cidr["CidrIp"]):
                      raise InvalidCIDRSubnetError(cidr=cidr)
  
          self._verify_group_will_respect_rule_count_limit(
              group,
              group.get_number_of_egress_rules(),
              ip_ranges,
              source_group_names,
              source_group_ids,
          )
  
          source_group_names = source_group_names if source_group_names else []
          source_group_ids = source_group_ids if source_group_ids else []
  
          source_groups = []
          for source_group_name in source_group_names:
              source_group = self.get_security_group_from_name(source_group_name, vpc_id)
              if source_group:
                  source_groups.append(source_group)
  
          # for VPCs
          for source_group_id in source_group_ids:
              source_group = self.get_security_group_from_id(source_group_id)
              if source_group:
                  source_groups.append(source_group)
  
          security_rule = SecurityRule(
              ip_protocol, from_port, to_port, ip_ranges, source_groups
          )
          group.add_egress_rule(security_rule)
  
      def revoke_security_group_egress(
          self,
          group_name_or_id,
          ip_protocol,
          from_port,
          to_port,
          ip_ranges,
          source_group_names=None,
          source_group_ids=None,
          vpc_id=None,
      ):
  
          group = self.get_security_group_by_name_or_id(group_name_or_id, vpc_id)
  
          source_groups = []
          for source_group_name in source_group_names:
              source_group = self.get_security_group_from_name(source_group_name, vpc_id)
              if source_group:
                  source_groups.append(source_group)
  
          for source_group_id in source_group_ids:
              source_group = self.get_security_group_from_id(source_group_id)
              if source_group:
                  source_groups.append(source_group)
  
          # I don't believe this is required after changing the default egress rule
          # to be {'CidrIp': '0.0.0.0/0'} instead of just '0.0.0.0/0'
          # Not sure why this would return only the IP if it was 0.0.0.0/0 instead of
          # the ip_range?
          # for ip in ip_ranges:
          #     ip_ranges = [ip.get("CidrIp") if ip.get("CidrIp") == "0.0.0.0/0" else ip]
  
          security_rule = SecurityRule(
              ip_protocol, from_port, to_port, ip_ranges, source_groups
          )
          if security_rule in group.egress_rules:
              group.egress_rules.remove(security_rule)
              return security_rule
          raise InvalidPermissionNotFoundError()
  
      def _verify_group_will_respect_rule_count_limit(
          self,
          group,
          current_rule_nb,
          ip_ranges,
          source_group_names=None,
          source_group_ids=None,
      ):
          max_nb_rules = 50 if group.vpc_id else 100
          future_group_nb_rules = current_rule_nb
          if ip_ranges:
              future_group_nb_rules += len(ip_ranges)
          if source_group_ids:
              future_group_nb_rules += len(source_group_ids)
          if source_group_names:
              future_group_nb_rules += len(source_group_names)
          if future_group_nb_rules > max_nb_rules:
              raise RulesPerSecurityGroupLimitExceededError
  
  
  class SecurityGroupIngress(CloudFormationModel):
      def __init__(self, security_group, properties):
          self.security_group = security_group
          self.properties = properties
  
      @staticmethod
      def cloudformation_name_type():
          return None
  
      @staticmethod
      def cloudformation_type():
          # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-securitygroupingress.html
          return "AWS::EC2::SecurityGroupIngress"
  
      @classmethod
      def create_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          properties = cloudformation_json["Properties"]
  
          ec2_backend = ec2_backends[region_name]
          group_name = properties.get("GroupName")
          group_id = properties.get("GroupId")
          ip_protocol = properties.get("IpProtocol")
          cidr_ip = properties.get("CidrIp")
          cidr_ipv6 = properties.get("CidrIpv6")
          from_port = properties.get("FromPort")
          source_security_group_id = properties.get("SourceSecurityGroupId")
          source_security_group_name = properties.get("SourceSecurityGroupName")
          # source_security_owner_id =
          # properties.get("SourceSecurityGroupOwnerId")  # IGNORED AT THE MOMENT
          to_port = properties.get("ToPort")
  
          assert group_id or group_name
          assert (
              source_security_group_name
              or cidr_ip
              or cidr_ipv6
              or source_security_group_id
          )
          assert ip_protocol
  
          if source_security_group_id:
              source_security_group_ids = [source_security_group_id]
          else:
              source_security_group_ids = None
          if source_security_group_name:
              source_security_group_names = [source_security_group_name]
          else:
              source_security_group_names = None
          if cidr_ip:
              ip_ranges = [cidr_ip]
          else:
              ip_ranges = []
  
          if group_id:
              security_group = ec2_backend.describe_security_groups(group_ids=[group_id])[
                  0
              ]
          else:
              security_group = ec2_backend.describe_security_groups(
                  groupnames=[group_name]
              )[0]
  
          ec2_backend.authorize_security_group_ingress(
              group_name_or_id=security_group.id,
              ip_protocol=ip_protocol,
              from_port=from_port,
              to_port=to_port,
              ip_ranges=ip_ranges,
              source_group_ids=source_security_group_ids,
              source_group_names=source_security_group_names,
          )
  
          return cls(security_group, properties)
  
  
  class VolumeAttachment(CloudFormationModel):
      def __init__(self, volume, instance, device, status):
          self.volume = volume
          self.attach_time = utc_date_and_time()
          self.instance = instance
          self.device = device
          self.status = status
  
      @staticmethod
      def cloudformation_name_type():
          return None
  
      @staticmethod
      def cloudformation_type():
          # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-volumeattachment.html
          return "AWS::EC2::VolumeAttachment"
  
      @classmethod
      def create_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          properties = cloudformation_json["Properties"]
  
          instance_id = properties["InstanceId"]
          volume_id = properties["VolumeId"]
  
          ec2_backend = ec2_backends[region_name]
          attachment = ec2_backend.attach_volume(
              volume_id=volume_id,
              instance_id=instance_id,
              device_path=properties["Device"],
          )
          return attachment
  
  
  class Volume(TaggedEC2Resource, CloudFormationModel):
      def __init__(
          self,
          ec2_backend,
          volume_id,
          size,
          zone,
          snapshot_id=None,
          encrypted=False,
          kms_key_id=None,
      ):
          self.id = volume_id
          self.size = size
          self.zone = zone
          self.create_time = utc_date_and_time()
          self.attachment = None
          self.snapshot_id = snapshot_id
          self.ec2_backend = ec2_backend
          self.encrypted = encrypted
          self.kms_key_id = kms_key_id
  
      @staticmethod
      def cloudformation_name_type():
          return None
  
      @staticmethod
      def cloudformation_type():
          # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-volume.html
          return "AWS::EC2::Volume"
  
      @classmethod
      def create_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          properties = cloudformation_json["Properties"]
  
          ec2_backend = ec2_backends[region_name]
          volume = ec2_backend.create_volume(
              size=properties.get("Size"), zone_name=properties.get("AvailabilityZone")
          )
          return volume
  
      @property
      def physical_resource_id(self):
          return self.id
  
      @property
      def status(self):
          if self.attachment:
              return "in-use"
          else:
              return "available"
  
      def get_filter_value(self, filter_name):
          if filter_name.startswith("attachment") and not self.attachment:
              return None
          elif filter_name == "attachment.attach-time":
              return self.attachment.attach_time
          elif filter_name == "attachment.device":
              return self.attachment.device
          elif filter_name == "attachment.instance-id":
              return self.attachment.instance.id
          elif filter_name == "attachment.status":
              return self.attachment.status
          elif filter_name == "create-time":
              return self.create_time
          elif filter_name == "size":
              return self.size
          elif filter_name == "snapshot-id":
              return self.snapshot_id
          elif filter_name == "status":
              return self.status
          elif filter_name == "volume-id":
              return self.id
          elif filter_name == "encrypted":
              return str(self.encrypted).lower()
          elif filter_name == "availability-zone":
              return self.zone.name
          else:
              return super(Volume, self).get_filter_value(filter_name, "DescribeVolumes")
  
  
  class Snapshot(TaggedEC2Resource):
      def __init__(
          self,
          ec2_backend,
          snapshot_id,
          volume,
          description,
          encrypted=False,
          owner_id=OWNER_ID,
      ):
          self.id = snapshot_id
          self.volume = volume
          self.description = description
          self.start_time = utc_date_and_time()
          self.create_volume_permission_groups = set()
          self.create_volume_permission_userids = set()
          self.ec2_backend = ec2_backend
          self.status = "completed"
          self.encrypted = encrypted
          self.owner_id = owner_id
  
      def get_filter_value(self, filter_name):
          if filter_name == "description":
              return self.description
          elif filter_name == "snapshot-id":
              return self.id
          elif filter_name == "start-time":
              return self.start_time
          elif filter_name == "volume-id":
              return self.volume.id
          elif filter_name == "volume-size":
              return self.volume.size
          elif filter_name == "encrypted":
              return str(self.encrypted).lower()
          elif filter_name == "status":
              return self.status
          elif filter_name == "owner-id":
              return self.owner_id
          else:
              return super(Snapshot, self).get_filter_value(
                  filter_name, "DescribeSnapshots"
              )
  
  
  class EBSBackend(object):
      def __init__(self):
          self.volumes = {}
          self.attachments = {}
          self.snapshots = {}
          super(EBSBackend, self).__init__()
  
      def create_volume(
          self, size, zone_name, snapshot_id=None, encrypted=False, kms_key_id=None
      ):
          if kms_key_id and not encrypted:
              raise InvalidParameterDependency("KmsKeyId", "Encrypted")
          if encrypted and not kms_key_id:
              kms_key_id = self._get_default_encryption_key()
          volume_id = random_volume_id()
          zone = self.get_zone_by_name(zone_name)
          if snapshot_id:
              snapshot = self.get_snapshot(snapshot_id)
              if size is None:
                  size = snapshot.volume.size
              if snapshot.encrypted:
                  encrypted = snapshot.encrypted
          volume = Volume(self, volume_id, size, zone, snapshot_id, encrypted, kms_key_id)
          self.volumes[volume_id] = volume
          return volume
  
      def describe_volumes(self, volume_ids=None, filters=None):
          matches = self.volumes.values()
          if volume_ids:
              matches = [vol for vol in matches if vol.id in volume_ids]
              if len(volume_ids) > len(matches):
                  unknown_ids = set(volume_ids) - set(matches)
                  raise InvalidVolumeIdError(unknown_ids)
          if filters:
              matches = generic_filter(filters, matches)
          return matches
  
      def get_volume(self, volume_id):
          volume = self.volumes.get(volume_id, None)
          if not volume:
              raise InvalidVolumeIdError(volume_id)
          return volume
  
      def delete_volume(self, volume_id):
          if volume_id in self.volumes:
              volume = self.volumes[volume_id]
              if volume.attachment:
                  raise VolumeInUseError(volume_id, volume.attachment.instance.id)
              return self.volumes.pop(volume_id)
          raise InvalidVolumeIdError(volume_id)
  
      def attach_volume(
          self, volume_id, instance_id, device_path, delete_on_termination=False
      ):
          volume = self.get_volume(volume_id)
          instance = self.get_instance(instance_id)
  
          if not volume or not instance:
              return False
  
          volume.attachment = VolumeAttachment(volume, instance, device_path, "attached")
          # Modify instance to capture mount of block device.
          bdt = BlockDeviceType(
              volume_id=volume_id,
              status=volume.status,
              size=volume.size,
              attach_time=utc_date_and_time(),
              delete_on_termination=delete_on_termination,
          )
          instance.block_device_mapping[device_path] = bdt
          return volume.attachment
  
      def detach_volume(self, volume_id, instance_id, device_path):
          volume = self.get_volume(volume_id)
          instance = self.get_instance(instance_id)
  
          old_attachment = volume.attachment
          if not old_attachment:
              raise InvalidVolumeAttachmentError(volume_id, instance_id)
          device_path = device_path or old_attachment.device
  
          try:
              del instance.block_device_mapping[device_path]
          except KeyError:
              raise InvalidVolumeDetachmentError(volume_id, instance_id, device_path)
  
          old_attachment.status = "detached"
  
          volume.attachment = None
          return old_attachment
  
      def create_snapshot(self, volume_id, description, owner_id=None):
          snapshot_id = random_snapshot_id()
          volume = self.get_volume(volume_id)
          params = [self, snapshot_id, volume, description, volume.encrypted]
          if owner_id:
              params.append(owner_id)
          snapshot = Snapshot(*params)
          self.snapshots[snapshot_id] = snapshot
          return snapshot
  
      def describe_snapshots(self, snapshot_ids=None, filters=None):
          matches = self.snapshots.values()
          if snapshot_ids:
              matches = [snap for snap in matches if snap.id in snapshot_ids]
              if len(snapshot_ids) > len(matches):
                  unknown_ids = set(snapshot_ids) - set(matches)
                  raise InvalidSnapshotIdError(unknown_ids)
          if filters:
              matches = generic_filter(filters, matches)
          return matches
  
      def copy_snapshot(self, source_snapshot_id, source_region, description=None):
          source_snapshot = ec2_backends[source_region].describe_snapshots(
              snapshot_ids=[source_snapshot_id]
          )[0]
          snapshot_id = random_snapshot_id()
          snapshot = Snapshot(
              self,
              snapshot_id,
              volume=source_snapshot.volume,
              description=description,
              encrypted=source_snapshot.encrypted,
          )
          self.snapshots[snapshot_id] = snapshot
          return snapshot
  
      def get_snapshot(self, snapshot_id):
          snapshot = self.snapshots.get(snapshot_id, None)
          if not snapshot:
              raise InvalidSnapshotIdError(snapshot_id)
          return snapshot
  
      def delete_snapshot(self, snapshot_id):
          if snapshot_id in self.snapshots:
              return self.snapshots.pop(snapshot_id)
          raise InvalidSnapshotIdError(snapshot_id)
  
      def get_create_volume_permission_groups(self, snapshot_id):
          snapshot = self.get_snapshot(snapshot_id)
          return snapshot.create_volume_permission_groups
  
      def get_create_volume_permission_userids(self, snapshot_id):
          snapshot = self.get_snapshot(snapshot_id)
          return snapshot.create_volume_permission_userids
  
      def add_create_volume_permission(self, snapshot_id, user_ids=None, groups=None):
          snapshot = self.get_snapshot(snapshot_id)
          if user_ids:
              snapshot.create_volume_permission_userids.update(user_ids)
  
          if groups and groups != ["all"]:
              raise InvalidAMIAttributeItemValueError("UserGroup", groups)
          else:
              snapshot.create_volume_permission_groups.update(groups)
  
          return True
  
      def remove_create_volume_permission(self, snapshot_id, user_ids=None, groups=None):
          snapshot = self.get_snapshot(snapshot_id)
          if user_ids:
              snapshot.create_volume_permission_userids.difference_update(user_ids)
  
          if groups and groups != ["all"]:
              raise InvalidAMIAttributeItemValueError("UserGroup", groups)
          else:
              snapshot.create_volume_permission_groups.difference_update(groups)
  
          return True
  
      def _get_default_encryption_key(self):
          # https://aws.amazon.com/kms/features/#AWS_Service_Integration
          # An AWS managed CMK is created automatically when you first create
          # an encrypted resource using an AWS service integrated with KMS.
          kms = kms_backends[self.region_name]
          ebs_alias = "alias/aws/ebs"
          if not kms.alias_exists(ebs_alias):
              key = kms.create_key(
                  policy="",
                  key_usage="ENCRYPT_DECRYPT",
                  customer_master_key_spec="SYMMETRIC_DEFAULT",
                  description="Default master key that protects my EBS volumes when no other key is defined",
                  tags=None,
                  region=self.region_name,
              )
              kms.add_alias(key.id, ebs_alias)
          ebs_key = kms.describe_key(ebs_alias)
          return ebs_key.arn
  
  
  class VPC(TaggedEC2Resource, CloudFormationModel):
      def __init__(
          self,
          ec2_backend,
          vpc_id,
          cidr_block,
          is_default,
          instance_tenancy="default",
          amazon_provided_ipv6_cidr_block=False,
      ):
  
          self.ec2_backend = ec2_backend
          self.id = vpc_id
          self.cidr_block = cidr_block
          self.cidr_block_association_set = {}
          self.dhcp_options = None
          self.state = "available"
          self.instance_tenancy = instance_tenancy
          self.is_default = "true" if is_default else "false"
          self.enable_dns_support = "true"
          self.classic_link_enabled = "false"
          self.classic_link_dns_supported = "false"
          # This attribute is set to 'true' only for default VPCs
          # or VPCs created using the wizard of the VPC console
          self.enable_dns_hostnames = "true" if is_default else "false"
  
          self.associate_vpc_cidr_block(cidr_block)
          if amazon_provided_ipv6_cidr_block:
              self.associate_vpc_cidr_block(
                  cidr_block,
                  amazon_provided_ipv6_cidr_block=amazon_provided_ipv6_cidr_block,
              )
  
      @staticmethod
      def cloudformation_name_type():
          return None
  
      @staticmethod
      def cloudformation_type():
          # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-vpc.html
          return "AWS::EC2::VPC"
  
      @classmethod
      def create_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          properties = cloudformation_json["Properties"]
  
          ec2_backend = ec2_backends[region_name]
          vpc = ec2_backend.create_vpc(
              cidr_block=properties["CidrBlock"],
              instance_tenancy=properties.get("InstanceTenancy", "default"),
          )
          for tag in properties.get("Tags", []):
              tag_key = tag["Key"]
              tag_value = tag["Value"]
              vpc.add_tag(tag_key, tag_value)
  
          return vpc
  
      @property
      def physical_resource_id(self):
          return self.id
  
      def get_filter_value(self, filter_name):
          if filter_name in ("vpc-id", "vpcId"):
              return self.id
          elif filter_name in ("cidr", "cidr-block", "cidrBlock"):
              return self.cidr_block
          elif filter_name in (
              "cidr-block-association.cidr-block",
              "ipv6-cidr-block-association.ipv6-cidr-block",
          ):
              return [
                  c["cidr_block"]
                  for c in self.get_cidr_block_association_set(ipv6="ipv6" in filter_name)
              ]
          elif filter_name in (
              "cidr-block-association.association-id",
              "ipv6-cidr-block-association.association-id",
          ):
              return self.cidr_block_association_set.keys()
          elif filter_name in (
              "cidr-block-association.state",
              "ipv6-cidr-block-association.state",
          ):
              return [
                  c["cidr_block_state"]["state"]
                  for c in self.get_cidr_block_association_set(ipv6="ipv6" in filter_name)
              ]
          elif filter_name in ("instance_tenancy", "InstanceTenancy"):
              return self.instance_tenancy
          elif filter_name in ("is-default", "isDefault"):
              return self.is_default
          elif filter_name == "state":
              return self.state
          elif filter_name in ("dhcp-options-id", "dhcpOptionsId"):
              if not self.dhcp_options:
                  return None
              return self.dhcp_options.id
          else:
              return super(VPC, self).get_filter_value(filter_name, "DescribeVpcs")
  
      def associate_vpc_cidr_block(
          self, cidr_block, amazon_provided_ipv6_cidr_block=False
      ):
          max_associations = 5 if not amazon_provided_ipv6_cidr_block else 1
  
          if (
              len(self.get_cidr_block_association_set(amazon_provided_ipv6_cidr_block))
              >= max_associations
          ):
              raise CidrLimitExceeded(self.id, max_associations)
  
          association_id = random_vpc_cidr_association_id()
  
          association_set = {
              "association_id": association_id,
              "cidr_block_state": {"state": "associated", "StatusMessage": ""},
          }
  
          association_set["cidr_block"] = (
              random_ipv6_cidr() if amazon_provided_ipv6_cidr_block else cidr_block
          )
          self.cidr_block_association_set[association_id] = association_set
          return association_set
  
      def enable_vpc_classic_link(self):
          # Check if current cidr block doesn't fall within the 10.0.0.0/8 block, excluding 10.0.0.0/16 and 10.1.0.0/16.
          # Doesn't check any route tables, maybe something for in the future?
          # See https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/vpc-classiclink.html#classiclink-limitations
          network_address = ipaddress.ip_network(self.cidr_block).network_address
          if (
              network_address not in ipaddress.ip_network("10.0.0.0/8")
              or network_address in ipaddress.ip_network("10.0.0.0/16")
              or network_address in ipaddress.ip_network("10.1.0.0/16")
          ):
              self.classic_link_enabled = "true"
  
          return self.classic_link_enabled
  
      def disable_vpc_classic_link(self):
          self.classic_link_enabled = "false"
          return self.classic_link_enabled
  
      def enable_vpc_classic_link_dns_support(self):
          self.classic_link_dns_supported = "true"
          return self.classic_link_dns_supported
  
      def disable_vpc_classic_link_dns_support(self):
          self.classic_link_dns_supported = "false"
          return self.classic_link_dns_supported
  
      def disassociate_vpc_cidr_block(self, association_id):
          if self.cidr_block == self.cidr_block_association_set.get(
              association_id, {}
          ).get("cidr_block"):
              raise OperationNotPermitted(association_id)
  
          entry = response = self.cidr_block_association_set.get(association_id, {})
          if entry:
              response = json.loads(json.dumps(entry))
              response["vpc_id"] = self.id
              response["cidr_block_state"]["state"] = "disassociating"
              entry["cidr_block_state"]["state"] = "disassociated"
          return response
  
      def get_cidr_block_association_set(self, ipv6=False):
          return [
              c
              for c in self.cidr_block_association_set.values()
              if ("::/" if ipv6 else ".") in c.get("cidr_block")
          ]
  
  
  class VPCBackend(object):
      vpc_refs = defaultdict(set)
  
      def __init__(self):
          self.vpcs = {}
          self.vpc_end_points = {}
          self.vpc_refs[self.__class__].add(weakref.ref(self))
          super(VPCBackend, self).__init__()
  
      @classmethod
      def get_vpc_refs(cls):
          for inst_ref in cls.vpc_refs[cls]:
              inst = inst_ref()
              if inst is not None:
                  yield inst
  
      def create_vpc(
          self,
          cidr_block,
          instance_tenancy="default",
          amazon_provided_ipv6_cidr_block=False,
          tags=[],
      ):
          vpc_id = random_vpc_id()
          try:
              vpc_cidr_block = ipaddress.IPv4Network(
                  six.text_type(cidr_block), strict=False
              )
          except ValueError:
              raise InvalidCIDRBlockParameterError(cidr_block)
          if vpc_cidr_block.prefixlen < 16 or vpc_cidr_block.prefixlen > 28:
              raise InvalidVPCRangeError(cidr_block)
          vpc = VPC(
              self,
              vpc_id,
              cidr_block,
              len(self.vpcs) == 0,
              instance_tenancy,
              amazon_provided_ipv6_cidr_block,
          )
  
          for tag in tags:
              tag_key = tag.get("Key")
              tag_value = tag.get("Value")
              vpc.add_tag(tag_key, tag_value)
  
          self.vpcs[vpc_id] = vpc
  
          # AWS creates a default main route table and security group.
          self.create_route_table(vpc_id, main=True)
  
          # AWS creates a default Network ACL
          self.create_network_acl(vpc_id, default=True)
  
          default = self.get_security_group_from_name("default", vpc_id=vpc_id)
          if not default:
              self.create_security_group(
                  "default", "default VPC security group", vpc_id=vpc_id
              )
  
          return vpc
  
      def get_vpc(self, vpc_id):
          if vpc_id not in self.vpcs:
              raise InvalidVPCIdError(vpc_id)
          return self.vpcs.get(vpc_id)
  
      # get vpc by vpc id and aws region
      def get_cross_vpc(self, vpc_id, peer_region):
          for vpcs in self.get_vpc_refs():
              if vpcs.region_name == peer_region:
                  match_vpc = vpcs.get_vpc(vpc_id)
          return match_vpc
  
      def get_all_vpcs(self, vpc_ids=None, filters=None):
          matches = self.vpcs.values()
          if vpc_ids:
              matches = [vpc for vpc in matches if vpc.id in vpc_ids]
              if len(vpc_ids) > len(matches):
                  unknown_ids = set(vpc_ids) - set(matches)
                  raise InvalidVPCIdError(unknown_ids)
          if filters:
              matches = generic_filter(filters, matches)
          return matches
  
      def delete_vpc(self, vpc_id):
          # Delete route table if only main route table remains.
          route_tables = self.get_all_route_tables(filters={"vpc-id": vpc_id})
          if len(route_tables) > 1:
              raise DependencyViolationError(
                  "The vpc {0} has dependencies and cannot be deleted.".format(vpc_id)
              )
          for route_table in route_tables:
              self.delete_route_table(route_table.id)
  
          # Delete default security group if exists.
          default = self.get_security_group_from_name("default", vpc_id=vpc_id)
          if default:
              self.delete_security_group(group_id=default.id)
  
          # Now delete VPC.
          vpc = self.vpcs.pop(vpc_id, None)
          if not vpc:
              raise InvalidVPCIdError(vpc_id)
  
          if vpc.dhcp_options:
              vpc.dhcp_options.vpc = None
              self.delete_dhcp_options_set(vpc.dhcp_options.id)
              vpc.dhcp_options = None
          return vpc
  
      def describe_vpc_attribute(self, vpc_id, attr_name):
          vpc = self.get_vpc(vpc_id)
          if attr_name in ("enable_dns_support", "enable_dns_hostnames"):
              return getattr(vpc, attr_name)
          else:
              raise InvalidParameterValueError(attr_name)
  
      def enable_vpc_classic_link(self, vpc_id):
          vpc = self.get_vpc(vpc_id)
          return vpc.enable_vpc_classic_link()
  
      def disable_vpc_classic_link(self, vpc_id):
          vpc = self.get_vpc(vpc_id)
          return vpc.disable_vpc_classic_link()
  
      def enable_vpc_classic_link_dns_support(self, vpc_id):
          vpc = self.get_vpc(vpc_id)
          return vpc.enable_vpc_classic_link_dns_support()
  
      def disable_vpc_classic_link_dns_support(self, vpc_id):
          vpc = self.get_vpc(vpc_id)
          return vpc.disable_vpc_classic_link_dns_support()
  
      def modify_vpc_attribute(self, vpc_id, attr_name, attr_value):
          vpc = self.get_vpc(vpc_id)
          if attr_name in ("enable_dns_support", "enable_dns_hostnames"):
              setattr(vpc, attr_name, attr_value)
          else:
              raise InvalidParameterValueError(attr_name)
  
      def disassociate_vpc_cidr_block(self, association_id):
          for vpc in self.vpcs.values():
              response = vpc.disassociate_vpc_cidr_block(association_id)
              if response:
                  return response
          else:
              raise InvalidVpcCidrBlockAssociationIdError(association_id)
  
      def associate_vpc_cidr_block(
          self, vpc_id, cidr_block, amazon_provided_ipv6_cidr_block
      ):
          vpc = self.get_vpc(vpc_id)
          return vpc.associate_vpc_cidr_block(cidr_block, amazon_provided_ipv6_cidr_block)
  
      def create_vpc_endpoint(
          self,
          vpc_id,
          service_name,
          type=None,
          policy_document=False,
          route_table_ids=None,
          subnet_ids=[],
          network_interface_ids=[],
          dns_entries=None,
          client_token=None,
          security_group=None,
          tag_specifications=None,
          private_dns_enabled=None,
      ):
  
          vpc_endpoint_id = generate_vpc_end_point_id(vpc_id)
  
          # validates if vpc is present or not.
          self.get_vpc(vpc_id)
  
          if type and type.lower() == "interface":
  
              network_interface_ids = []
              for subnet_id in subnet_ids:
                  self.get_subnet(subnet_id)
                  eni = self.create_network_interface(subnet_id, random_private_ip())
                  network_interface_ids.append(eni.id)
  
              dns_entries = create_dns_entries(service_name, vpc_endpoint_id)
  
          else:
              # considering gateway if type is not mentioned.
              service_destination_cidr = randor_ipv4_cidr()
  
              for route_table_id in route_table_ids:
                  self.create_route(route_table_id, service_destination_cidr)
          if dns_entries:
              dns_entries = [dns_entries]
  
          vpc_end_point = VPCEndPoint(
              vpc_endpoint_id,
              vpc_id,
              service_name,
              type,
              policy_document,
              route_table_ids,
              subnet_ids,
              network_interface_ids,
              dns_entries,
              client_token,
              security_group,
              tag_specifications,
              private_dns_enabled,
          )
  
          self.vpc_end_points[vpc_endpoint_id] = vpc_end_point
  
          return vpc_end_point
  
      def get_vpc_end_point_services(self):
          vpc_end_point_services = self.vpc_end_points.values()
  
          services = []
          for value in vpc_end_point_services:
              services.append(value.service_name)
  
          availability_zones = EC2Backend.describe_availability_zones(self)
  
          return {
              "servicesDetails": vpc_end_point_services,
              "services": services,
              "availability_zones": availability_zones,
          }
  
  
  class VPCPeeringConnectionStatus(object):
      def __init__(self, code="initiating-request", message=""):
          self.code = code
          self.message = message
  
      def deleted(self):
          self.code = "deleted"
          self.message = "Deleted by {deleter ID}"
  
      def initiating(self):
          self.code = "initiating-request"
          self.message = "Initiating Request to {accepter ID}"
  
      def pending(self):
          self.code = "pending-acceptance"
          self.message = "Pending Acceptance by {accepter ID}"
  
      def accept(self):
          self.code = "active"
          self.message = "Active"
  
      def reject(self):
          self.code = "rejected"
          self.message = "Inactive"
  
  
  class VPCPeeringConnection(TaggedEC2Resource, CloudFormationModel):
      def __init__(self, vpc_pcx_id, vpc, peer_vpc):
          self.id = vpc_pcx_id
          self.vpc = vpc
          self.peer_vpc = peer_vpc
          self._status = VPCPeeringConnectionStatus()
  
      @staticmethod
      def cloudformation_name_type():
          return None
  
      @staticmethod
      def cloudformation_type():
          # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-vpcpeeringconnection.html
          return "AWS::EC2::VPCPeeringConnection"
  
      @classmethod
      def create_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          properties = cloudformation_json["Properties"]
  
          ec2_backend = ec2_backends[region_name]
          vpc = ec2_backend.get_vpc(properties["VpcId"])
          peer_vpc = ec2_backend.get_vpc(properties["PeerVpcId"])
  
          vpc_pcx = ec2_backend.create_vpc_peering_connection(vpc, peer_vpc)
  
          return vpc_pcx
  
      @property
      def physical_resource_id(self):
          return self.id
  
  
  class VPCPeeringConnectionBackend(object):
      # for cross region vpc reference
      vpc_pcx_refs = defaultdict(set)
  
      def __init__(self):
          self.vpc_pcxs = {}
          self.vpc_pcx_refs[self.__class__].add(weakref.ref(self))
          super(VPCPeeringConnectionBackend, self).__init__()
  
      @classmethod
      def get_vpc_pcx_refs(cls):
          for inst_ref in cls.vpc_pcx_refs[cls]:
              inst = inst_ref()
              if inst is not None:
                  yield inst
  
      def create_vpc_peering_connection(self, vpc, peer_vpc):
          vpc_pcx_id = random_vpc_peering_connection_id()
          vpc_pcx = VPCPeeringConnection(vpc_pcx_id, vpc, peer_vpc)
          vpc_pcx._status.pending()
          self.vpc_pcxs[vpc_pcx_id] = vpc_pcx
          # insert cross region peering info
          if vpc.ec2_backend.region_name != peer_vpc.ec2_backend.region_name:
              for vpc_pcx_cx in peer_vpc.ec2_backend.get_vpc_pcx_refs():
                  if vpc_pcx_cx.region_name == peer_vpc.ec2_backend.region_name:
                      vpc_pcx_cx.vpc_pcxs[vpc_pcx_id] = vpc_pcx
          return vpc_pcx
  
      def get_all_vpc_peering_connections(self):
          return self.vpc_pcxs.values()
  
      def get_vpc_peering_connection(self, vpc_pcx_id):
          if vpc_pcx_id not in self.vpc_pcxs:
              raise InvalidVPCPeeringConnectionIdError(vpc_pcx_id)
          return self.vpc_pcxs.get(vpc_pcx_id)
  
      def delete_vpc_peering_connection(self, vpc_pcx_id):
          deleted = self.get_vpc_peering_connection(vpc_pcx_id)
          deleted._status.deleted()
          return deleted
  
      def accept_vpc_peering_connection(self, vpc_pcx_id):
          vpc_pcx = self.get_vpc_peering_connection(vpc_pcx_id)
          # if cross region need accepter from another region
          pcx_req_region = vpc_pcx.vpc.ec2_backend.region_name
          pcx_acp_region = vpc_pcx.peer_vpc.ec2_backend.region_name
          if pcx_req_region != pcx_acp_region and self.region_name == pcx_req_region:
              raise OperationNotPermitted2(self.region_name, vpc_pcx.id, pcx_acp_region)
          if vpc_pcx._status.code != "pending-acceptance":
              raise InvalidVPCPeeringConnectionStateTransitionError(vpc_pcx.id)
          vpc_pcx._status.accept()
          return vpc_pcx
  
      def reject_vpc_peering_connection(self, vpc_pcx_id):
          vpc_pcx = self.get_vpc_peering_connection(vpc_pcx_id)
          # if cross region need accepter from another region
          pcx_req_region = vpc_pcx.vpc.ec2_backend.region_name
          pcx_acp_region = vpc_pcx.peer_vpc.ec2_backend.region_name
          if pcx_req_region != pcx_acp_region and self.region_name == pcx_req_region:
              raise OperationNotPermitted3(self.region_name, vpc_pcx.id, pcx_acp_region)
          if vpc_pcx._status.code != "pending-acceptance":
              raise InvalidVPCPeeringConnectionStateTransitionError(vpc_pcx.id)
          vpc_pcx._status.reject()
          return vpc_pcx
  
  
  class Subnet(TaggedEC2Resource, CloudFormationModel):
      def __init__(
          self,
          ec2_backend,
          subnet_id,
          vpc_id,
          cidr_block,
          availability_zone,
          default_for_az,
          map_public_ip_on_launch,
          owner_id=OWNER_ID,
          assign_ipv6_address_on_creation=False,
      ):
          self.ec2_backend = ec2_backend
          self.id = subnet_id
          self.vpc_id = vpc_id
          self.cidr_block = cidr_block
          self.cidr = ipaddress.IPv4Network(six.text_type(self.cidr_block), strict=False)
          self._available_ip_addresses = (
              ipaddress.IPv4Network(six.text_type(self.cidr_block)).num_addresses - 5
          )
          self._availability_zone = availability_zone
          self.default_for_az = default_for_az
          self.map_public_ip_on_launch = map_public_ip_on_launch
          self.owner_id = owner_id
          self.assign_ipv6_address_on_creation = assign_ipv6_address_on_creation
          self.ipv6_cidr_block_associations = []
  
          # Theory is we assign ip's as we go (as 16,777,214 usable IPs in a /8)
          self._subnet_ip_generator = self.cidr.hosts()
          self.reserved_ips = [
              six.next(self._subnet_ip_generator) for _ in range(0, 3)
          ]  # Reserved by AWS
          self._unused_ips = set()  # if instance is destroyed hold IP here for reuse
          self._subnet_ips = {}  # has IP: instance
  
      @staticmethod
      def cloudformation_name_type():
          return None
  
      @staticmethod
      def cloudformation_type():
          # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-subnet.html
          return "AWS::EC2::Subnet"
  
      @classmethod
      def create_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          properties = cloudformation_json["Properties"]
  
          vpc_id = properties["VpcId"]
          cidr_block = properties["CidrBlock"]
          availability_zone = properties.get("AvailabilityZone")
          ec2_backend = ec2_backends[region_name]
          subnet = ec2_backend.create_subnet(
              vpc_id=vpc_id, cidr_block=cidr_block, availability_zone=availability_zone
          )
          for tag in properties.get("Tags", []):
              tag_key = tag["Key"]
              tag_value = tag["Value"]
              subnet.add_tag(tag_key, tag_value)
  
          return subnet
  
      @property
      def available_ip_addresses(self):
          enis = [
              eni
              for eni in self.ec2_backend.get_all_network_interfaces()
              if eni.subnet.id == self.id
          ]
          addresses_taken = [
              eni.private_ip_address for eni in enis if eni.private_ip_address
          ]
          for eni in enis:
              if eni.private_ip_addresses:
                  addresses_taken.extend(eni.private_ip_addresses)
          return str(self._available_ip_addresses - len(addresses_taken))
  
      @property
      def availability_zone(self):
          return self._availability_zone.name
  
      @property
      def physical_resource_id(self):
          return self.id
  
      def get_filter_value(self, filter_name):
          """
          API Version 2014-10-01 defines the following filters for DescribeSubnets:
  
          * availabilityZone
          * available-ip-address-count
          * cidrBlock
          * defaultForAz
          * state
          * subnet-id
          * tag:key=value
          * tag-key
          * tag-value
          * vpc-id
  
          Taken from: http://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_DescribeSubnets.html
          """
          if filter_name in ("cidr", "cidrBlock", "cidr-block"):
              return self.cidr_block
          elif filter_name in ("vpc-id", "vpcId"):
              return self.vpc_id
          elif filter_name == "subnet-id":
              return self.id
          elif filter_name in ("availabilityZone", "availability-zone"):
              return self.availability_zone
          elif filter_name in ("defaultForAz", "default-for-az"):
              return self.default_for_az
          else:
              return super(Subnet, self).get_filter_value(filter_name, "DescribeSubnets")
  
      def get_cfn_attribute(self, attribute_name):
          from moto.cloudformation.exceptions import UnformattedGetAttTemplateException
  
          if attribute_name == "AvailabilityZone":
              raise NotImplementedError('"Fn::GetAtt" : [ "{0}" , "AvailabilityZone" ]"')
          raise UnformattedGetAttTemplateException()
  
      def get_available_subnet_ip(self, instance):
          try:
              new_ip = self._unused_ips.pop()
          except KeyError:
              new_ip = six.next(self._subnet_ip_generator)
  
              # Skips any IP's if they've been manually specified
              while str(new_ip) in self._subnet_ips:
                  new_ip = six.next(self._subnet_ip_generator)
  
              if new_ip == self.cidr.broadcast_address:
                  raise StopIteration()  # Broadcast address cant be used obviously
          # TODO StopIteration will be raised if no ip's available, not sure how aws handles this.
  
          new_ip = str(new_ip)
          self._subnet_ips[new_ip] = instance
  
          return new_ip
  
      def request_ip(self, ip, instance):
          if ipaddress.ip_address(ip) not in self.cidr:
              raise Exception(
                  "IP does not fall in the subnet CIDR of {0}".format(self.cidr)
              )
  
          if ip in self._subnet_ips:
              raise Exception("IP already in use")
          try:
              self._unused_ips.remove(ip)
          except KeyError:
              pass
  
          self._subnet_ips[ip] = instance
          return ip
  
      def del_subnet_ip(self, ip):
          try:
              del self._subnet_ips[ip]
              self._unused_ips.add(ip)
          except KeyError:
              pass  # Unknown IP
  
  
  class SubnetBackend(object):
      def __init__(self):
          # maps availability zone to dict of (subnet_id, subnet)
          self.subnets = defaultdict(dict)
          super(SubnetBackend, self).__init__()
  
      def get_subnet(self, subnet_id):
          for subnets in self.subnets.values():
              if subnet_id in subnets:
                  return subnets[subnet_id]
          raise InvalidSubnetIdError(subnet_id)
  
      def create_subnet(
          self,
          vpc_id,
          cidr_block,
          availability_zone=None,
          availability_zone_id=None,
          context=None,
          tags=[],
      ):
          subnet_id = random_subnet_id()
          vpc = self.get_vpc(
              vpc_id
          )  # Validate VPC exists and the supplied CIDR block is a subnet of the VPC's
          vpc_cidr_blocks = [
              ipaddress.IPv4Network(
                  six.text_type(cidr_block_association["cidr_block"]), strict=False
              )
              for cidr_block_association in vpc.get_cidr_block_association_set()
          ]
          try:
              subnet_cidr_block = ipaddress.IPv4Network(
                  six.text_type(cidr_block), strict=False
              )
          except ValueError:
              raise InvalidCIDRBlockParameterError(cidr_block)
  
          subnet_in_vpc_cidr_range = False
          for vpc_cidr_block in vpc_cidr_blocks:
              if (
                  vpc_cidr_block.network_address <= subnet_cidr_block.network_address
                  and vpc_cidr_block.broadcast_address
                  >= subnet_cidr_block.broadcast_address
              ):
                  subnet_in_vpc_cidr_range = True
                  break
  
          if not subnet_in_vpc_cidr_range:
              raise InvalidSubnetRangeError(cidr_block)
  
          for subnet in self.get_all_subnets(filters={"vpc-id": vpc_id}):
              if subnet.cidr.overlaps(subnet_cidr_block):
                  raise InvalidSubnetConflictError(cidr_block)
  
          # if this is the first subnet for an availability zone,
          # consider it the default
          default_for_az = str(availability_zone not in self.subnets).lower()
          map_public_ip_on_launch = default_for_az
  
          if availability_zone is None and not availability_zone_id:
              availability_zone = "us-east-1a"
          try:
              if availability_zone:
                  availability_zone_data = next(
                      zone
                      for zones in RegionsAndZonesBackend.zones.values()
                      for zone in zones
                      if zone.name == availability_zone
                  )
              elif availability_zone_id:
                  availability_zone_data = next(
                      zone
                      for zones in RegionsAndZonesBackend.zones.values()
                      for zone in zones
                      if zone.zone_id == availability_zone_id
                  )
  
          except StopIteration:
              raise InvalidAvailabilityZoneError(
                  availability_zone,
                  ", ".join(
                      [
                          zone.name
                          for zones in RegionsAndZonesBackend.zones.values()
                          for zone in zones
                      ]
                  ),
              )
          subnet = Subnet(
              self,
              subnet_id,
              vpc_id,
              cidr_block,
              availability_zone_data,
              default_for_az,
              map_public_ip_on_launch,
              owner_id=context.get_current_user() if context else OWNER_ID,
              assign_ipv6_address_on_creation=False,
          )
  
          for tag in tags:
              tag_key = tag.get("Key")
              tag_value = tag.get("Value")
              subnet.add_tag(tag_key, tag_value)
  
          # AWS associates a new subnet with the default Network ACL
          self.associate_default_network_acl_with_subnet(subnet_id, vpc_id)
          self.subnets[availability_zone][subnet_id] = subnet
          return subnet
  
      def get_all_subnets(self, subnet_ids=None, filters=None):
          # Extract a list of all subnets
          matches = itertools.chain(*[x.values() for x in self.subnets.values()])
          if subnet_ids:
              matches = [sn for sn in matches if sn.id in subnet_ids]
              if len(subnet_ids) > len(matches):
                  unknown_ids = set(subnet_ids) - set(matches)
                  raise InvalidSubnetIdError(unknown_ids)
          if filters:
              matches = generic_filter(filters, matches)
  
          return matches
  
      def delete_subnet(self, subnet_id):
          for subnets in self.subnets.values():
              if subnet_id in subnets:
                  return subnets.pop(subnet_id, None)
          raise InvalidSubnetIdError(subnet_id)
  
      def modify_subnet_attribute(self, subnet_id, attr_name, attr_value):
          subnet = self.get_subnet(subnet_id)
          if attr_name in ("map_public_ip_on_launch", "assign_ipv6_address_on_creation"):
              setattr(subnet, attr_name, attr_value)
          else:
              raise InvalidParameterValueError(attr_name)
  
  
  class FlowLogs(TaggedEC2Resource, CloudFormationModel):
      def __init__(
          self,
          ec2_backend,
          flow_log_id,
          resource_id,
          traffic_type,
          log_destination,
          log_group_name,
          deliver_logs_permission_arn,
          max_aggregation_interval,
          log_destination_type,
          log_format,
          deliver_logs_status="SUCCESS",
          deliver_logs_error_message=None,
      ):
          self.ec2_backend = ec2_backend
          self.id = flow_log_id
          self.resource_id = resource_id
          self.traffic_type = traffic_type
          self.log_destination = log_destination
          self.log_group_name = log_group_name
          self.deliver_logs_permission_arn = deliver_logs_permission_arn
          self.deliver_logs_status = deliver_logs_status
          self.deliver_logs_error_message = deliver_logs_error_message
          self.max_aggregation_interval = max_aggregation_interval
          self.log_destination_type = log_destination_type
          self.log_format = log_format
  
          self.created_at = utc_date_and_time()
  
      @staticmethod
      def cloudformation_name_type():
          return None
  
      @staticmethod
      def cloudformation_type():
          # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-flowlog.html
          return "AWS::EC2::FlowLog"
  
      @classmethod
      def create_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          properties = cloudformation_json["Properties"]
  
          resource_type = properties.get("ResourceType")
          resource_id = [properties.get("ResourceId")]
          traffic_type = properties.get("TrafficType")
          deliver_logs_permission_arn = properties.get("DeliverLogsPermissionArn")
          log_destination_type = properties.get("LogDestinationType")
          log_destination = properties.get("LogDestination")
          log_group_name = properties.get("LogGroupName")
          log_format = properties.get("LogFormat")
          max_aggregation_interval = properties.get("MaxAggregationInterval")
  
          ec2_backend = ec2_backends[region_name]
          flow_log, _ = ec2_backend.create_flow_logs(
              resource_type,
              resource_id,
              traffic_type,
              deliver_logs_permission_arn,
              log_destination_type,
              log_destination,
              log_group_name,
              log_format,
              max_aggregation_interval,
          )
          for tag in properties.get("Tags", []):
              tag_key = tag["Key"]
              tag_value = tag["Value"]
              flow_log[0].add_tag(tag_key, tag_value)
  
          return flow_log[0]
  
      @property
      def physical_resource_id(self):
          return self.id
  
      def get_filter_value(self, filter_name):
          """
          API Version 2016-11-15 defines the following filters for DescribeFlowLogs:
  
          * deliver-log-status
          * log-destination-type
          * flow-log-id
          * log-group-name
          * resource-id
          * traffic-type
          * tag:key=value
          * tag-key
  
          Taken from: https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_DescribeFlowLogs.html
          """
          if filter_name == "resource-id":
              return self.resource_id
          elif filter_name == "traffic-type":
              return self.traffic_type
          elif filter_name == "log-destination-type":
              return self.log_destination_type
          elif filter_name == "flow-log-id":
              return self.id
          elif filter_name == "log-group-name":
              return self.log_group_name
          elif filter_name == "deliver-log-status":
              return "SUCCESS"
          else:
              return super(FlowLogs, self).get_filter_value(
                  filter_name, "DescribeFlowLogs"
              )
  
  
  class FlowLogsBackend(object):
      def __init__(self):
          self.flow_logs = defaultdict(dict)
          super(FlowLogsBackend, self).__init__()
  
      def _validate_request(
          self,
          log_group_name,
          log_destination,
          log_destination_type,
          max_aggregation_interval,
          deliver_logs_permission_arn,
      ):
          if log_group_name is None and log_destination is None:
              raise InvalidDependantParameterError(
                  "LogDestination", "LogGroupName", "not provided",
              )
  
          if log_destination_type == "s3":
              if log_group_name is not None:
                  raise InvalidDependantParameterTypeError(
                      "LogDestination", "cloud-watch-logs", "LogGroupName",
                  )
          elif log_destination_type == "cloud-watch-logs":
              if deliver_logs_permission_arn is None:
                  raise InvalidDependantParameterError(
                      "DeliverLogsPermissionArn",
                      "LogDestinationType",
                      "cloud-watch-logs",
                  )
  
          if max_aggregation_interval not in ["60", "600"]:
              raise InvalidAggregationIntervalParameterError(
                  "Flow Log Max Aggregation Interval"
              )
  
      def create_flow_logs(
          self,
          resource_type,
          resource_ids,
          traffic_type,
          deliver_logs_permission_arn,
          log_destination_type,
          log_destination,
          log_group_name,
          log_format,
          max_aggregation_interval,
      ):
          # Guess it's best to put it here due to possible
          # lack of them in the CloudFormation template
          max_aggregation_interval = (
              "600" if max_aggregation_interval is None else max_aggregation_interval
          )
          log_destination_type = (
              "cloud-watch-logs" if log_destination_type is None else log_destination_type
          )
          log_format = (
              "${version} ${account-id} ${interface-id} ${srcaddr} ${dstaddr} ${srcport} ${dstport} ${protocol} ${packets} ${bytes} ${start} ${end} ${action} ${log-status}"
              if log_format is None
              else log_format
          )
  
          # Validate the requests paremeters
          self._validate_request(
              log_group_name,
              log_destination,
              log_destination_type,
              max_aggregation_interval,
              deliver_logs_permission_arn,
          )
  
          flow_logs_set = []
          unsuccessful = []
  
          for resource_id in resource_ids:
              deliver_logs_status = "SUCCESS"
              deliver_logs_error_message = None
              flow_log_id = random_flow_log_id()
              if resource_type == "VPC":
                  # Validate VPCs exist
                  self.get_vpc(resource_id)
              elif resource_type == "Subnet":
                  # Validate Subnets exist
                  self.get_subnet(resource_id)
              elif resource_type == "NetworkInterface":
                  # Validate NetworkInterfaces exist
                  self.get_network_interface(resource_id)
  
              if log_destination_type == "s3":
                  from moto.s3.models import s3_backend
                  from moto.s3.exceptions import MissingBucket
  
                  arn = log_destination.split(":", 5)[5]
                  try:
                      s3_backend.get_bucket(arn)
                  except MissingBucket:
                      # Instead of creating FlowLog report
                      # the unsuccessful status for the
                      # given resource_id
                      unsuccessful.append(
                          (
                              resource_id,
                              "400",
                              "LogDestination: {0} does not exist.".format(arn),
                          )
                      )
                      continue
              elif log_destination_type == "cloud-watch-logs":
                  from moto.logs.models import logs_backends
                  from moto.logs.exceptions import ResourceNotFoundException
  
                  # API allows to create a FlowLog with a
                  # non-existing LogGroup. It however later
                  # on reports the FAILED delivery status.
                  try:
                      # Need something easy to check the group exists.
                      # The list_tags_log_group seems to do the trick.
                      logs_backends[self.region_name].list_tags_log_group(log_group_name)
                  except ResourceNotFoundException:
                      deliver_logs_status = "FAILED"
                      deliver_logs_error_message = "Access error"
  
              all_flow_logs = self.describe_flow_logs()
              if any(
                  fl.resource_id == resource_id
                  and (
                      fl.log_group_name == log_group_name
                      or fl.log_destination == log_destination
                  )
                  for fl in all_flow_logs
              ):
                  raise FlowLogAlreadyExists()
              flow_logs = FlowLogs(
                  self,
                  flow_log_id,
                  resource_id,
                  traffic_type,
                  log_destination,
                  log_group_name,
                  deliver_logs_permission_arn,
                  max_aggregation_interval,
                  log_destination_type,
                  log_format,
                  deliver_logs_status,
                  deliver_logs_error_message,
              )
              self.flow_logs[flow_log_id] = flow_logs
              flow_logs_set.append(flow_logs)
  
          return flow_logs_set, unsuccessful
  
      def describe_flow_logs(self, flow_log_ids=None, filters=None):
          matches = itertools.chain([i for i in self.flow_logs.values()])
          if flow_log_ids:
              matches = [flow_log for flow_log in matches if flow_log.id in flow_log_ids]
          if filters:
              matches = generic_filter(filters, matches)
          return matches
  
      def delete_flow_logs(self, flow_log_ids):
          non_existing = []
          for flow_log in flow_log_ids:
              if flow_log in self.flow_logs:
                  self.flow_logs.pop(flow_log, None)
              else:
                  non_existing.append(flow_log)
  
          if non_existing:
              raise InvalidFlowLogIdError(
                  len(flow_log_ids), " ".join(x for x in flow_log_ids),
              )
          return True
  
  
  class SubnetRouteTableAssociation(CloudFormationModel):
      def __init__(self, route_table_id, subnet_id):
          self.route_table_id = route_table_id
          self.subnet_id = subnet_id
  
      @staticmethod
      def cloudformation_name_type():
          return None
  
      @staticmethod
      def cloudformation_type():
          # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-subnetroutetableassociation.html
          return "AWS::EC2::SubnetRouteTableAssociation"
  
      @classmethod
      def create_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          properties = cloudformation_json["Properties"]
  
          route_table_id = properties["RouteTableId"]
          subnet_id = properties["SubnetId"]
  
          ec2_backend = ec2_backends[region_name]
          subnet_association = ec2_backend.create_subnet_association(
              route_table_id=route_table_id, subnet_id=subnet_id
          )
          return subnet_association
  
  
  class SubnetRouteTableAssociationBackend(object):
      def __init__(self):
          self.subnet_associations = {}
          super(SubnetRouteTableAssociationBackend, self).__init__()
  
      def create_subnet_association(self, route_table_id, subnet_id):
          subnet_association = SubnetRouteTableAssociation(route_table_id, subnet_id)
          self.subnet_associations[
              "{0}:{1}".format(route_table_id, subnet_id)
          ] = subnet_association
          return subnet_association
  
  
  class RouteTable(TaggedEC2Resource, CloudFormationModel):
      def __init__(self, ec2_backend, route_table_id, vpc_id, main=False):
          self.ec2_backend = ec2_backend
          self.id = route_table_id
          self.vpc_id = vpc_id
          self.main = main
          self.associations = {}
          self.routes = {}
  
      @staticmethod
      def cloudformation_name_type():
          return None
  
      @staticmethod
      def cloudformation_type():
          # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-routetable.html
          return "AWS::EC2::RouteTable"
  
      @classmethod
      def create_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          properties = cloudformation_json["Properties"]
  
          vpc_id = properties["VpcId"]
          ec2_backend = ec2_backends[region_name]
          route_table = ec2_backend.create_route_table(vpc_id=vpc_id)
          return route_table
  
      @property
      def physical_resource_id(self):
          return self.id
  
      def get_filter_value(self, filter_name):
          if filter_name == "association.main":
              # Note: Boto only supports 'true'.
              # https://github.com/boto/boto/issues/1742
              if self.main:
                  return "true"
              else:
                  return "false"
          elif filter_name == "route-table-id":
              return self.id
          elif filter_name == "vpc-id":
              return self.vpc_id
          elif filter_name == "association.route-table-id":
              return self.id
          elif filter_name == "association.route-table-association-id":
              return self.associations.keys()
          elif filter_name == "association.subnet-id":
              return self.associations.values()
          else:
              return super(RouteTable, self).get_filter_value(
                  filter_name, "DescribeRouteTables"
              )
  
  
  class RouteTableBackend(object):
      def __init__(self):
          self.route_tables = {}
          super(RouteTableBackend, self).__init__()
  
      def create_route_table(self, vpc_id, tags=[], main=False):
          route_table_id = random_route_table_id()
          vpc = self.get_vpc(vpc_id)  # Validate VPC exists
          route_table = RouteTable(self, route_table_id, vpc_id, main=main)
          for tag in tags:
              route_table.add_tag(tag.get("Key"), tag.get("Value"))
          self.route_tables[route_table_id] = route_table
  
          # AWS creates a default local route.
          self.create_route(route_table_id, vpc.cidr_block, local=True)
  
          return route_table
  
      def get_route_table(self, route_table_id):
          route_table = self.route_tables.get(route_table_id, None)
          if not route_table:
              raise InvalidRouteTableIdError(route_table_id)
          return route_table
  
      def get_all_route_tables(self, route_table_ids=None, filters=None):
          route_tables = self.route_tables.values()
  
          if route_table_ids:
              route_tables = [
                  route_table
                  for route_table in route_tables
                  if route_table.id in route_table_ids
              ]
              if len(route_tables) != len(route_table_ids):
                  invalid_id = list(
                      set(route_table_ids).difference(
                          set([route_table.id for route_table in route_tables])
                      )
                  )[0]
                  raise InvalidRouteTableIdError(invalid_id)
  
          return generic_filter(filters, route_tables)
  
      def delete_route_table(self, route_table_id):
          route_table = self.get_route_table(route_table_id)
          if route_table.associations:
              raise DependencyViolationError(
                  "The routeTable '{0}' has dependencies and cannot be deleted.".format(
                      route_table_id
                  )
              )
          self.route_tables.pop(route_table_id)
          return True
  
      def associate_route_table(self, route_table_id, subnet_id):
          # Idempotent if association already exists.
          route_tables_by_subnet = self.get_all_route_tables(
              filters={"association.subnet-id": [subnet_id]}
          )
          if route_tables_by_subnet:
              for association_id, check_subnet_id in route_tables_by_subnet[
                  0
              ].associations.items():
                  if subnet_id == check_subnet_id:
                      return association_id
  
          # Association does not yet exist, so create it.
          route_table = self.get_route_table(route_table_id)
          self.get_subnet(subnet_id)  # Validate subnet exists
          association_id = random_subnet_association_id()
          route_table.associations[association_id] = subnet_id
          return association_id
  
      def disassociate_route_table(self, association_id):
          for route_table in self.route_tables.values():
              if association_id in route_table.associations:
                  return route_table.associations.pop(association_id, None)
          raise InvalidAssociationIdError(association_id)
  
      def replace_route_table_association(self, association_id, route_table_id):
          # Idempotent if association already exists.
          new_route_table = self.get_route_table(route_table_id)
          if association_id in new_route_table.associations:
              return association_id
  
          # Find route table which currently has the association, error if none.
          route_tables_by_association_id = self.get_all_route_tables(
              filters={"association.route-table-association-id": [association_id]}
          )
          if not route_tables_by_association_id:
              raise InvalidAssociationIdError(association_id)
  
          # Remove existing association, create new one.
          previous_route_table = route_tables_by_association_id[0]
          subnet_id = previous_route_table.associations.pop(association_id, None)
          return self.associate_route_table(route_table_id, subnet_id)
  
  
  class Route(CloudFormationModel):
      def __init__(
          self,
          route_table,
          destination_cidr_block,
          destination_ipv6_cidr_block,
          local=False,
          gateway=None,
          instance=None,
          nat_gateway=None,
          interface=None,
          vpc_pcx=None,
      ):
          self.id = generate_route_id(
              route_table.id, destination_cidr_block, destination_ipv6_cidr_block
          )
          self.route_table = route_table
          self.destination_cidr_block = destination_cidr_block
          self.destination_ipv6_cidr_block = destination_ipv6_cidr_block
          self.local = local
          self.gateway = gateway
          self.instance = instance
          self.nat_gateway = nat_gateway
          self.interface = interface
          self.vpc_pcx = vpc_pcx
  
      @staticmethod
      def cloudformation_name_type():
          return None
  
      @staticmethod
      def cloudformation_type():
          # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-route.html
          return "AWS::EC2::Route"
  
      @classmethod
      def create_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          properties = cloudformation_json["Properties"]
  
          gateway_id = properties.get("GatewayId")
          instance_id = properties.get("InstanceId")
          interface_id = properties.get("NetworkInterfaceId")
          nat_gateway_id = properties.get("NatGatewayId")
          pcx_id = properties.get("VpcPeeringConnectionId")
  
          route_table_id = properties["RouteTableId"]
          ec2_backend = ec2_backends[region_name]
          route_table = ec2_backend.create_route(
              route_table_id=route_table_id,
              destination_cidr_block=properties.get("DestinationCidrBlock"),
              gateway_id=gateway_id,
              instance_id=instance_id,
              nat_gateway_id=nat_gateway_id,
              interface_id=interface_id,
              vpc_peering_connection_id=pcx_id,
          )
          return route_table
  
  
  class VPCEndPoint(TaggedEC2Resource):
      def __init__(
          self,
          id,
          vpc_id,
          service_name,
          type=None,
          policy_document=False,
          route_table_ids=None,
          subnet_ids=None,
          network_interface_ids=None,
          dns_entries=None,
          client_token=None,
          security_group=None,
          tag_specifications=None,
          private_dns_enabled=None,
      ):
          self.id = id
          self.vpc_id = vpc_id
          self.service_name = service_name
          self.type = type
          self.policy_document = policy_document
          self.route_table_ids = route_table_ids
          self.network_interface_ids = network_interface_ids
          self.subnet_ids = subnet_ids
          self.client_token = client_token
          self.security_group = security_group
          self.tag_specifications = tag_specifications
          self.private_dns_enabled = private_dns_enabled
          self.created_at = datetime.utcnow()
          self.dns_entries = dns_entries
  
  
  class RouteBackend(object):
      def __init__(self):
          super(RouteBackend, self).__init__()
  
      def create_route(
          self,
          route_table_id,
          destination_cidr_block,
          destination_ipv6_cidr_block=None,
          local=False,
          gateway_id=None,
          instance_id=None,
          nat_gateway_id=None,
          interface_id=None,
          vpc_peering_connection_id=None,
      ):
          gateway = None
          nat_gateway = None
  
          route_table = self.get_route_table(route_table_id)
  
          if interface_id:
              # for validating interface Id whether it is valid or not.
              self.get_network_interface(interface_id)
  
          else:
              if gateway_id:
                  if EC2_RESOURCE_TO_PREFIX["vpn-gateway"] in gateway_id:
                      gateway = self.get_vpn_gateway(gateway_id)
                  elif EC2_RESOURCE_TO_PREFIX["internet-gateway"] in gateway_id:
                      gateway = self.get_internet_gateway(gateway_id)
  
              try:
                  if destination_cidr_block:
                      ipaddress.IPv4Network(
                          six.text_type(destination_cidr_block), strict=False
                      )
              except ValueError:
                  raise InvalidDestinationCIDRBlockParameterError(destination_cidr_block)
  
              if nat_gateway_id is not None:
                  nat_gateway = self.nat_gateways.get(nat_gateway_id)
  
          route = Route(
              route_table,
              destination_cidr_block,
              destination_ipv6_cidr_block,
              local=local,
              gateway=gateway,
              instance=self.get_instance(instance_id) if instance_id else None,
              nat_gateway=nat_gateway,
              interface=None,
              vpc_pcx=self.get_vpc_peering_connection(vpc_peering_connection_id)
              if vpc_peering_connection_id
              else None,
          )
          route_table.routes[route.id] = route
          return route
  
      def replace_route(
          self,
          route_table_id,
          destination_cidr_block,
          gateway_id=None,
          instance_id=None,
          interface_id=None,
          vpc_peering_connection_id=None,
      ):
          route_table = self.get_route_table(route_table_id)
          route_id = generate_route_id(route_table.id, destination_cidr_block)
          route = route_table.routes[route_id]
  
          if interface_id:
              self.raise_not_implemented_error("ReplaceRoute to NetworkInterfaceId")
  
          route.gateway = None
          if gateway_id:
              if EC2_RESOURCE_TO_PREFIX["vpn-gateway"] in gateway_id:
                  route.gateway = self.get_vpn_gateway(gateway_id)
              elif EC2_RESOURCE_TO_PREFIX["internet-gateway"] in gateway_id:
                  route.gateway = self.get_internet_gateway(gateway_id)
  
          route.instance = self.get_instance(instance_id) if instance_id else None
          route.interface = None
          route.vpc_pcx = (
              self.get_vpc_peering_connection(vpc_peering_connection_id)
              if vpc_peering_connection_id
              else None
          )
  
          route_table.routes[route.id] = route
          return route
  
      def get_route(self, route_id):
          route_table_id, destination_cidr_block = split_route_id(route_id)
          route_table = self.get_route_table(route_table_id)
          return route_table.get(route_id)
  
      def delete_route(self, route_table_id, destination_cidr_block):
          route_table = self.get_route_table(route_table_id)
          route_id = generate_route_id(route_table_id, destination_cidr_block)
          deleted = route_table.routes.pop(route_id, None)
          if not deleted:
              raise InvalidRouteError(route_table_id, destination_cidr_block)
          return deleted
  
  
  class InternetGateway(TaggedEC2Resource, CloudFormationModel):
      def __init__(self, ec2_backend):
          self.ec2_backend = ec2_backend
          self.id = random_internet_gateway_id()
          self.vpc = None
  
      @staticmethod
      def cloudformation_name_type():
          return None
  
      @staticmethod
      def cloudformation_type():
          # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-internetgateway.html
          return "AWS::EC2::InternetGateway"
  
      @classmethod
      def create_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          ec2_backend = ec2_backends[region_name]
          return ec2_backend.create_internet_gateway()
  
      @property
      def physical_resource_id(self):
          return self.id
  
      @property
      def attachment_state(self):
          if self.vpc:
              return "available"
          else:
              return "detached"
  
  
  class InternetGatewayBackend(object):
      def __init__(self):
          self.internet_gateways = {}
          super(InternetGatewayBackend, self).__init__()
  
      def create_internet_gateway(self, tags=[]):
          igw = InternetGateway(self)
          for tag in tags:
              igw.add_tag(tag.get("Key"), tag.get("Value"))
          self.internet_gateways[igw.id] = igw
          return igw
  
      def describe_internet_gateways(self, internet_gateway_ids=None, filters=None):
          igws = []
          if internet_gateway_ids is None:
              igws = self.internet_gateways.values()
          else:
              for igw_id in internet_gateway_ids:
                  if igw_id in self.internet_gateways:
                      igws.append(self.internet_gateways[igw_id])
                  else:
                      raise InvalidInternetGatewayIdError(igw_id)
          if filters is not None:
              igws = filter_internet_gateways(igws, filters)
          return igws
  
      def delete_internet_gateway(self, internet_gateway_id):
          igw = self.get_internet_gateway(internet_gateway_id)
          if igw.vpc:
              raise DependencyViolationError(
                  "{0} is being utilized by {1}".format(internet_gateway_id, igw.vpc.id)
              )
          self.internet_gateways.pop(internet_gateway_id)
          return True
  
      def detach_internet_gateway(self, internet_gateway_id, vpc_id):
          igw = self.get_internet_gateway(internet_gateway_id)
          if not igw.vpc or igw.vpc.id != vpc_id:
              raise GatewayNotAttachedError(internet_gateway_id, vpc_id)
          igw.vpc = None
          return True
  
      def attach_internet_gateway(self, internet_gateway_id, vpc_id):
          igw = self.get_internet_gateway(internet_gateway_id)
          if igw.vpc:
              raise ResourceAlreadyAssociatedError(internet_gateway_id)
          vpc = self.get_vpc(vpc_id)
          igw.vpc = vpc
          return True
  
      def get_internet_gateway(self, internet_gateway_id):
          igw_ids = [internet_gateway_id]
          return self.describe_internet_gateways(internet_gateway_ids=igw_ids)[0]
  
  
  class VPCGatewayAttachment(CloudFormationModel):
      def __init__(self, gateway_id, vpc_id):
          self.gateway_id = gateway_id
          self.vpc_id = vpc_id
  
      @staticmethod
      def cloudformation_name_type():
          return None
  
      @staticmethod
      def cloudformation_type():
          # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-vpcgatewayattachment.html
          return "AWS::EC2::VPCGatewayAttachment"
  
      @classmethod
      def create_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          properties = cloudformation_json["Properties"]
  
          ec2_backend = ec2_backends[region_name]
          attachment = ec2_backend.create_vpc_gateway_attachment(
              gateway_id=properties["InternetGatewayId"], vpc_id=properties["VpcId"]
          )
          ec2_backend.attach_internet_gateway(
              properties["InternetGatewayId"], properties["VpcId"]
          )
          return attachment
  
      @property
      def physical_resource_id(self):
          return self.vpc_id
  
  
  class VPCGatewayAttachmentBackend(object):
      def __init__(self):
          self.gateway_attachments = {}
          super(VPCGatewayAttachmentBackend, self).__init__()
  
      def create_vpc_gateway_attachment(self, vpc_id, gateway_id):
          attachment = VPCGatewayAttachment(vpc_id, gateway_id)
          self.gateway_attachments[gateway_id] = attachment
          return attachment
  
  
  class SpotInstanceRequest(BotoSpotRequest, TaggedEC2Resource):
      def __init__(
          self,
          ec2_backend,
          spot_request_id,
          price,
          image_id,
          type,
          valid_from,
          valid_until,
          launch_group,
          availability_zone_group,
          key_name,
          security_groups,
          user_data,
          instance_type,
          placement,
          kernel_id,
          ramdisk_id,
          monitoring_enabled,
          subnet_id,
          tags,
          spot_fleet_id,
          **kwargs
      ):
          super(SpotInstanceRequest, self).__init__(**kwargs)
          ls = LaunchSpecification()
          self.ec2_backend = ec2_backend
          self.launch_specification = ls
          self.id = spot_request_id
          self.state = "open"
          self.price = price
          self.type = type
          self.valid_from = valid_from
          self.valid_until = valid_until
          self.launch_group = launch_group
          self.availability_zone_group = availability_zone_group
          self.user_data = user_data  # NOT
          ls.kernel = kernel_id
          ls.ramdisk = ramdisk_id
          ls.image_id = image_id
          ls.key_name = key_name
          ls.instance_type = instance_type
          ls.placement = placement
          ls.monitored = monitoring_enabled
          ls.subnet_id = subnet_id
          self.spot_fleet_id = spot_fleet_id
          self.tags = tags
  
          if security_groups:
              for group_name in security_groups:
                  group = self.ec2_backend.get_security_group_from_name(group_name)
                  if group:
                      ls.groups.append(group)
          else:
              # If not security groups, add the default
              default_group = self.ec2_backend.get_security_group_from_name("default")
              ls.groups.append(default_group)
  
          self.instance = self.launch_instance()
  
      def get_filter_value(self, filter_name):
          if filter_name == "state":
              return self.state
          elif filter_name == "spot-instance-request-id":
              return self.id
          else:
              return super(SpotInstanceRequest, self).get_filter_value(
                  filter_name, "DescribeSpotInstanceRequests"
              )
  
      def launch_instance(self):
          reservation = self.ec2_backend.add_instances(
              image_id=self.launch_specification.image_id,
              count=1,
              user_data=self.user_data,
              instance_type=self.launch_specification.instance_type,
              subnet_id=self.launch_specification.subnet_id,
              key_name=self.launch_specification.key_name,
              security_group_names=[],
              security_group_ids=self.launch_specification.groups,
              spot_fleet_id=self.spot_fleet_id,
              tags=self.tags,
          )
          instance = reservation.instances[0]
          return instance
  
  
  @six.add_metaclass(Model)
  class SpotRequestBackend(object):
      def __init__(self):
          self.spot_instance_requests = {}
          super(SpotRequestBackend, self).__init__()
  
      def request_spot_instances(
          self,
          price,
          image_id,
          count,
          type,
          valid_from,
          valid_until,
          launch_group,
          availability_zone_group,
          key_name,
          security_groups,
          user_data,
          instance_type,
          placement,
          kernel_id,
          ramdisk_id,
          monitoring_enabled,
          subnet_id,
          tags=None,
          spot_fleet_id=None,
      ):
          requests = []
          tags = tags or {}
          for _ in range(count):
              spot_request_id = random_spot_request_id()
              request = SpotInstanceRequest(
                  self,
                  spot_request_id,
                  price,
                  image_id,
                  type,
                  valid_from,
                  valid_until,
                  launch_group,
                  availability_zone_group,
                  key_name,
                  security_groups,
                  user_data,
                  instance_type,
                  placement,
                  kernel_id,
                  ramdisk_id,
                  monitoring_enabled,
                  subnet_id,
                  tags,
                  spot_fleet_id,
              )
              self.spot_instance_requests[spot_request_id] = request
              requests.append(request)
          return requests
  
      @Model.prop("SpotInstanceRequest")
      def describe_spot_instance_requests(self, filters=None):
          requests = self.spot_instance_requests.values()
  
          return generic_filter(filters, requests)
  
      def cancel_spot_instance_requests(self, request_ids):
          requests = []
          for request_id in request_ids:
              requests.append(self.spot_instance_requests.pop(request_id))
          return requests
  
  
  class SpotFleetLaunchSpec(object):
      def __init__(
          self,
          ebs_optimized,
          group_set,
          iam_instance_profile,
          image_id,
          instance_type,
          key_name,
          monitoring,
          spot_price,
          subnet_id,
          tag_specifications,
          user_data,
          weighted_capacity,
      ):
          self.ebs_optimized = ebs_optimized
          self.group_set = group_set
          self.iam_instance_profile = iam_instance_profile
          self.image_id = image_id
          self.instance_type = instance_type
          self.key_name = key_name
          self.monitoring = monitoring
          self.spot_price = spot_price
          self.subnet_id = subnet_id
          self.tag_specifications = tag_specifications
          self.user_data = user_data
          self.weighted_capacity = float(weighted_capacity)
  
  
  class SpotFleetRequest(TaggedEC2Resource, CloudFormationModel):
      def __init__(
          self,
          ec2_backend,
          spot_fleet_request_id,
          spot_price,
          target_capacity,
          iam_fleet_role,
          allocation_strategy,
          launch_specs,
      ):
  
          self.ec2_backend = ec2_backend
          self.id = spot_fleet_request_id
          self.spot_price = spot_price
          self.target_capacity = int(target_capacity)
          self.iam_fleet_role = iam_fleet_role
          self.allocation_strategy = allocation_strategy
          self.state = "active"
          self.fulfilled_capacity = 0.0
  
          self.launch_specs = []
          for spec in launch_specs:
              self.launch_specs.append(
                  SpotFleetLaunchSpec(
                      ebs_optimized=spec["ebs_optimized"],
                      group_set=[
                          val for key, val in spec.items() if key.startswith("group_set")
                      ],
                      iam_instance_profile=spec.get("iam_instance_profile._arn"),
                      image_id=spec["image_id"],
                      instance_type=spec["instance_type"],
                      key_name=spec.get("key_name"),
                      monitoring=spec.get("monitoring._enabled"),
                      spot_price=spec.get("spot_price", self.spot_price),
                      subnet_id=spec["subnet_id"],
                      tag_specifications=self._parse_tag_specifications(spec),
                      user_data=spec.get("user_data"),
                      weighted_capacity=spec["weighted_capacity"],
                  )
              )
  
          self.spot_requests = []
          self.create_spot_requests(self.target_capacity)
  
      @property
      def physical_resource_id(self):
          return self.id
  
      @staticmethod
      def cloudformation_name_type():
          return None
  
      @staticmethod
      def cloudformation_type():
          # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-spotfleet.html
          return "AWS::EC2::SpotFleet"
  
      @classmethod
      def create_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          properties = cloudformation_json["Properties"]["SpotFleetRequestConfigData"]
          ec2_backend = ec2_backends[region_name]
  
          spot_price = properties.get("SpotPrice")
          target_capacity = properties["TargetCapacity"]
          iam_fleet_role = properties["IamFleetRole"]
          allocation_strategy = properties["AllocationStrategy"]
          launch_specs = properties["LaunchSpecifications"]
          launch_specs = [
              dict(
                  [
                      (camelcase_to_underscores(key), val)
                      for key, val in launch_spec.items()
                  ]
              )
              for launch_spec in launch_specs
          ]
  
          spot_fleet_request = ec2_backend.request_spot_fleet(
              spot_price,
              target_capacity,
              iam_fleet_role,
              allocation_strategy,
              launch_specs,
          )
  
          return spot_fleet_request
  
      def get_launch_spec_counts(self, weight_to_add):
          weight_map = defaultdict(int)
  
          weight_so_far = 0
          if self.allocation_strategy == "diversified":
              launch_spec_index = 0
              while True:
                  launch_spec = self.launch_specs[
                      launch_spec_index % len(self.launch_specs)
                  ]
                  weight_map[launch_spec] += 1
                  weight_so_far += launch_spec.weighted_capacity
                  if weight_so_far >= weight_to_add:
                      break
                  launch_spec_index += 1
          else:  # lowestPrice
              cheapest_spec = sorted(
                  # FIXME: change `+inf` to the on demand price scaled to weighted capacity when it's not present
                  self.launch_specs,
                  key=lambda spec: float(spec.spot_price or "+inf"),
              )[0]
              weight_so_far = weight_to_add + (
                  weight_to_add % cheapest_spec.weighted_capacity
              )
              weight_map[cheapest_spec] = int(
                  weight_so_far // cheapest_spec.weighted_capacity
              )
  
          return weight_map, weight_so_far
  
      def create_spot_requests(self, weight_to_add):
          weight_map, added_weight = self.get_launch_spec_counts(weight_to_add)
          for launch_spec, count in weight_map.items():
              requests = self.ec2_backend.request_spot_instances(
                  price=launch_spec.spot_price,
                  image_id=launch_spec.image_id,
                  count=count,
                  type="persistent",
                  valid_from=None,
                  valid_until=None,
                  launch_group=None,
                  availability_zone_group=None,
                  key_name=launch_spec.key_name,
                  security_groups=launch_spec.group_set,
                  user_data=launch_spec.user_data,
                  instance_type=launch_spec.instance_type,
                  placement=None,
                  kernel_id=None,
                  ramdisk_id=None,
                  monitoring_enabled=launch_spec.monitoring,
                  subnet_id=launch_spec.subnet_id,
                  spot_fleet_id=self.id,
                  tags=launch_spec.tag_specifications,
              )
              self.spot_requests.extend(requests)
          self.fulfilled_capacity += added_weight
          return self.spot_requests
  
      def terminate_instances(self):
          instance_ids = []
          new_fulfilled_capacity = self.fulfilled_capacity
          for req in self.spot_requests:
              instance = req.instance
              for spec in self.launch_specs:
                  if (
                      spec.instance_type == instance.instance_type
                      and spec.subnet_id == instance.subnet_id
                  ):
                      break
  
              if new_fulfilled_capacity - spec.weighted_capacity < self.target_capacity:
                  continue
              new_fulfilled_capacity -= spec.weighted_capacity
              instance_ids.append(instance.id)
  
          self.spot_requests = [
              req for req in self.spot_requests if req.instance.id not in instance_ids
          ]
          self.ec2_backend.terminate_instances(instance_ids)
  
      def _parse_tag_specifications(self, spec):
          try:
              tag_spec_num = max(
                  [
                      int(key.split(".")[1])
                      for key in spec
                      if key.startswith("tag_specification_set")
                  ]
              )
          except ValueError:  # no tag specifications
              return {}
  
          tag_specifications = {}
          for si in range(1, tag_spec_num + 1):
              resource_type = spec[
                  "tag_specification_set.{si}._resource_type".format(si=si)
              ]
  
              tags = [
                  key
                  for key in spec
                  if key.startswith("tag_specification_set.{si}._tag".format(si=si))
              ]
              tag_num = max([int(key.split(".")[3]) for key in tags])
              tag_specifications[resource_type] = dict(
                  (
                      spec[
                          "tag_specification_set.{si}._tag.{ti}._key".format(si=si, ti=ti)
                      ],
                      spec[
                          "tag_specification_set.{si}._tag.{ti}._value".format(
                              si=si, ti=ti
                          )
                      ],
                  )
                  for ti in range(1, tag_num + 1)
              )
  
          return tag_specifications
  
  
  class SpotFleetBackend(object):
      def __init__(self):
          self.spot_fleet_requests = {}
          super(SpotFleetBackend, self).__init__()
  
      def request_spot_fleet(
          self,
          spot_price,
          target_capacity,
          iam_fleet_role,
          allocation_strategy,
          launch_specs,
      ):
  
          spot_fleet_request_id = random_spot_fleet_request_id()
          request = SpotFleetRequest(
              self,
              spot_fleet_request_id,
              spot_price,
              target_capacity,
              iam_fleet_role,
              allocation_strategy,
              launch_specs,
          )
          self.spot_fleet_requests[spot_fleet_request_id] = request
          return request
  
      def get_spot_fleet_request(self, spot_fleet_request_id):
          return self.spot_fleet_requests[spot_fleet_request_id]
  
      def describe_spot_fleet_instances(self, spot_fleet_request_id):
          spot_fleet = self.get_spot_fleet_request(spot_fleet_request_id)
          return spot_fleet.spot_requests
  
      def describe_spot_fleet_requests(self, spot_fleet_request_ids):
          requests = self.spot_fleet_requests.values()
  
          if spot_fleet_request_ids:
              requests = [
                  request for request in requests if request.id in spot_fleet_request_ids
              ]
  
          return requests
  
      def cancel_spot_fleet_requests(self, spot_fleet_request_ids, terminate_instances):
          spot_requests = []
          for spot_fleet_request_id in spot_fleet_request_ids:
              spot_fleet = self.spot_fleet_requests[spot_fleet_request_id]
              if terminate_instances:
                  spot_fleet.target_capacity = 0
                  spot_fleet.terminate_instances()
              spot_requests.append(spot_fleet)
              del self.spot_fleet_requests[spot_fleet_request_id]
          return spot_requests
  
      def modify_spot_fleet_request(
          self, spot_fleet_request_id, target_capacity, terminate_instances
      ):
          if target_capacity < 0:
              raise ValueError("Cannot reduce spot fleet capacity below 0")
          spot_fleet_request = self.spot_fleet_requests[spot_fleet_request_id]
          delta = target_capacity - spot_fleet_request.fulfilled_capacity
          spot_fleet_request.target_capacity = target_capacity
          if delta > 0:
              spot_fleet_request.create_spot_requests(delta)
          elif delta < 0 and terminate_instances == "Default":
              spot_fleet_request.terminate_instances()
          return True
  
  
  class ElasticAddress(TaggedEC2Resource, CloudFormationModel):
      def __init__(self, ec2_backend, domain, address=None):
          self.ec2_backend = ec2_backend
          if address:
              self.public_ip = address
          else:
              self.public_ip = random_ip()
          self.allocation_id = random_eip_allocation_id() if domain == "vpc" else None
          self.id = self.allocation_id
          self.domain = domain
          self.instance = None
          self.eni = None
          self.association_id = None
  
      @staticmethod
      def cloudformation_name_type():
          return None
  
      @staticmethod
      def cloudformation_type():
          # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-eip.html
          return "AWS::EC2::EIP"
  
      @classmethod
      def create_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          ec2_backend = ec2_backends[region_name]
  
          properties = cloudformation_json.get("Properties")
          instance_id = None
          if properties:
              domain = properties.get("Domain")
              eip = ec2_backend.allocate_address(domain=domain if domain else "standard")
              instance_id = properties.get("InstanceId")
          else:
              eip = ec2_backend.allocate_address(domain="standard")
  
          if instance_id:
              instance = ec2_backend.get_instance_by_id(instance_id)
              ec2_backend.associate_address(instance, address=eip.public_ip)
  
          return eip
  
      @property
      def physical_resource_id(self):
          return self.public_ip
  
      def get_cfn_attribute(self, attribute_name):
          from moto.cloudformation.exceptions import UnformattedGetAttTemplateException
  
          if attribute_name == "AllocationId":
              return self.allocation_id
          raise UnformattedGetAttTemplateException()
  
      def get_filter_value(self, filter_name):
          if filter_name == "allocation-id":
              return self.allocation_id
          elif filter_name == "association-id":
              return self.association_id
          elif filter_name == "domain":
              return self.domain
          elif filter_name == "instance-id" and self.instance:
              return self.instance.id
          elif filter_name == "network-interface-id" and self.eni:
              return self.eni.id
          elif filter_name == "private-ip-address" and self.eni:
              return self.eni.private_ip_address
          elif filter_name == "public-ip":
              return self.public_ip
          elif filter_name == "network-interface-owner-id":
              # TODO: implement network-interface-owner-id
              raise FilterNotImplementedError(filter_name, "DescribeAddresses")
          else:
              return super(ElasticAddress, self).get_filter_value(
                  filter_name, "DescribeAddresses"
              )
  
  
  class ElasticAddressBackend(object):
      def __init__(self):
          self.addresses = []
          super(ElasticAddressBackend, self).__init__()
  
      def allocate_address(self, domain, address=None):
          if domain not in ["standard", "vpc"]:
              raise InvalidDomainError(domain)
          if address:
              address = ElasticAddress(self, domain=domain, address=address)
          else:
              address = ElasticAddress(self, domain=domain)
          self.addresses.append(address)
          return address
  
      def address_by_ip(self, ips):
          eips = [address for address in self.addresses if address.public_ip in ips]
  
          # TODO: Trim error message down to specific invalid address.
          if not eips or len(ips) > len(eips):
              raise InvalidAddressError(ips)
  
          return eips
  
      def address_by_allocation(self, allocation_ids):
          eips = [
              address
              for address in self.addresses
              if address.allocation_id in allocation_ids
          ]
  
          # TODO: Trim error message down to specific invalid id.
          if not eips or len(allocation_ids) > len(eips):
              raise InvalidAllocationIdError(allocation_ids)
  
          return eips
  
      def address_by_association(self, association_ids):
          eips = [
              address
              for address in self.addresses
              if address.association_id in association_ids
          ]
  
          # TODO: Trim error message down to specific invalid id.
          if not eips or len(association_ids) > len(eips):
              raise InvalidAssociationIdError(association_ids)
  
          return eips
  
      def associate_address(
          self,
          instance=None,
          eni=None,
          address=None,
          allocation_id=None,
          reassociate=False,
      ):
          eips = []
          if address:
              eips = self.address_by_ip([address])
          elif allocation_id:
              eips = self.address_by_allocation([allocation_id])
          eip = eips[0]
  
          new_instance_association = bool(
              instance and (not eip.instance or eip.instance.id == instance.id)
          )
          new_eni_association = bool(eni and (not eip.eni or eni.id == eip.eni.id))
  
          if new_instance_association or new_eni_association or reassociate:
              eip.instance = instance
              eip.eni = eni
              if not eip.eni and instance:
                  # default to primary network interface
                  eip.eni = instance.nics[0]
              if eip.eni:
                  eip.eni.public_ip = eip.public_ip
              if eip.domain == "vpc":
                  eip.association_id = random_eip_association_id()
  
              return eip
  
          raise ResourceAlreadyAssociatedError(eip.public_ip)
  
      def describe_addresses(self, allocation_ids=None, public_ips=None, filters=None):
          matches = self.addresses
          if allocation_ids:
              matches = [addr for addr in matches if addr.allocation_id in allocation_ids]
              if len(allocation_ids) > len(matches):
                  unknown_ids = set(allocation_ids) - set(matches)
                  raise InvalidAllocationIdError(unknown_ids)
          if public_ips:
              matches = [addr for addr in matches if addr.public_ip in public_ips]
              if len(public_ips) > len(matches):
                  unknown_ips = set(allocation_ids) - set(matches)
                  raise InvalidAddressError(unknown_ips)
          if filters:
              matches = generic_filter(filters, matches)
  
          return matches
  
      def disassociate_address(self, address=None, association_id=None):
          eips = []
          if address:
              eips = self.address_by_ip([address])
          elif association_id:
              eips = self.address_by_association([association_id])
          eip = eips[0]
  
          if eip.eni:
              eip.eni.public_ip = None
              if eip.eni.instance and eip.eni.instance._state.name == "running":
                  eip.eni.check_auto_public_ip()
              eip.eni = None
  
          eip.instance = None
          eip.association_id = None
          return True
  
      def release_address(self, address=None, allocation_id=None):
          eips = []
          if address:
              eips = self.address_by_ip([address])
          elif allocation_id:
              eips = self.address_by_allocation([allocation_id])
          eip = eips[0]
  
          self.disassociate_address(address=eip.public_ip)
          eip.allocation_id = None
          self.addresses.remove(eip)
          return True
  
  
  class DHCPOptionsSet(TaggedEC2Resource):
      def __init__(
          self,
          ec2_backend,
          domain_name_servers=None,
          domain_name=None,
          ntp_servers=None,
          netbios_name_servers=None,
          netbios_node_type=None,
      ):
          self.ec2_backend = ec2_backend
          self._options = {
              "domain-name-servers": domain_name_servers,
              "domain-name": domain_name,
              "ntp-servers": ntp_servers,
              "netbios-name-servers": netbios_name_servers,
              "netbios-node-type": netbios_node_type,
          }
          self.id = random_dhcp_option_id()
          self.vpc = None
  
      def get_filter_value(self, filter_name):
          """
          API Version 2015-10-01 defines the following filters for DescribeDhcpOptions:
  
          * dhcp-options-id
          * key
          * value
          * tag:key=value
          * tag-key
          * tag-value
  
          Taken from: http://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_DescribeDhcpOptions.html
          """
          if filter_name == "dhcp-options-id":
              return self.id
          elif filter_name == "key":
              return list(self._options.keys())
          elif filter_name == "value":
              values = [item for item in list(self._options.values()) if item]
              return itertools.chain(*values)
          else:
              return super(DHCPOptionsSet, self).get_filter_value(
                  filter_name, "DescribeDhcpOptions"
              )
  
      @property
      def options(self):
          return self._options
  
  
  class DHCPOptionsSetBackend(object):
      def __init__(self):
          self.dhcp_options_sets = {}
          super(DHCPOptionsSetBackend, self).__init__()
  
      def associate_dhcp_options(self, dhcp_options, vpc):
          dhcp_options.vpc = vpc
          vpc.dhcp_options = dhcp_options
  
      def create_dhcp_options(
          self,
          domain_name_servers=None,
          domain_name=None,
          ntp_servers=None,
          netbios_name_servers=None,
          netbios_node_type=None,
      ):
  
          NETBIOS_NODE_TYPES = [1, 2, 4, 8]
  
          for field_value in domain_name_servers, ntp_servers, netbios_name_servers:
              if field_value and len(field_value) > 4:
                  raise InvalidParameterValueError(",".join(field_value))
  
          if netbios_node_type and int(netbios_node_type[0]) not in NETBIOS_NODE_TYPES:
              raise InvalidParameterValueError(netbios_node_type)
  
          options = DHCPOptionsSet(
              self,
              domain_name_servers,
              domain_name,
              ntp_servers,
              netbios_name_servers,
              netbios_node_type,
          )
          self.dhcp_options_sets[options.id] = options
          return options
  
      def describe_dhcp_options(self, options_ids=None):
          options_sets = []
          for option_id in options_ids or []:
              if option_id in self.dhcp_options_sets:
                  options_sets.append(self.dhcp_options_sets[option_id])
              else:
                  raise InvalidDHCPOptionsIdError(option_id)
          return options_sets or self.dhcp_options_sets.values()
  
      def delete_dhcp_options_set(self, options_id):
          if not (options_id and options_id.startswith("dopt-")):
              raise MalformedDHCPOptionsIdError(options_id)
  
          if options_id in self.dhcp_options_sets:
              if self.dhcp_options_sets[options_id].vpc:
                  raise DependencyViolationError("Cannot delete assigned DHCP options.")
              self.dhcp_options_sets.pop(options_id)
          else:
              raise InvalidDHCPOptionsIdError(options_id)
          return True
  
      def get_all_dhcp_options(self, dhcp_options_ids=None, filters=None):
          dhcp_options_sets = self.dhcp_options_sets.values()
  
          if dhcp_options_ids:
              dhcp_options_sets = [
                  dhcp_options_set
                  for dhcp_options_set in dhcp_options_sets
                  if dhcp_options_set.id in dhcp_options_ids
              ]
              if len(dhcp_options_sets) != len(dhcp_options_ids):
                  invalid_id = list(
                      set(dhcp_options_ids).difference(
                          set(
                              [
                                  dhcp_options_set.id
                                  for dhcp_options_set in dhcp_options_sets
                              ]
                          )
                      )
                  )[0]
                  raise InvalidDHCPOptionsIdError(invalid_id)
  
          return generic_filter(filters, dhcp_options_sets)
  
  
  class VPNConnection(TaggedEC2Resource):
      def __init__(self, ec2_backend, id, type, customer_gateway_id, vpn_gateway_id):
          self.ec2_backend = ec2_backend
          self.id = id
          self.state = "available"
          self.customer_gateway_configuration = {}
          self.type = type
          self.customer_gateway_id = customer_gateway_id
          self.vpn_gateway_id = vpn_gateway_id
          self.tunnels = None
          self.options = None
          self.static_routes = None
  
      def get_filter_value(self, filter_name):
          return super(VPNConnection, self).get_filter_value(
              filter_name, "DescribeVpnConnections"
          )
  
  
  class VPNConnectionBackend(object):
      def __init__(self):
          self.vpn_connections = {}
          super(VPNConnectionBackend, self).__init__()
  
      def create_vpn_connection(
          self, type, customer_gateway_id, vpn_gateway_id, static_routes_only=None
      ):
          vpn_connection_id = random_vpn_connection_id()
          if static_routes_only:
              pass
          vpn_connection = VPNConnection(
              self,
              id=vpn_connection_id,
              type=type,
              customer_gateway_id=customer_gateway_id,
              vpn_gateway_id=vpn_gateway_id,
          )
          self.vpn_connections[vpn_connection.id] = vpn_connection
          return vpn_connection
  
      def delete_vpn_connection(self, vpn_connection_id):
  
          if vpn_connection_id in self.vpn_connections:
              self.vpn_connections.pop(vpn_connection_id)
          else:
              raise InvalidVpnConnectionIdError(vpn_connection_id)
          return True
  
      def describe_vpn_connections(self, vpn_connection_ids=None):
          vpn_connections = []
          for vpn_connection_id in vpn_connection_ids or []:
              if vpn_connection_id in self.vpn_connections:
                  vpn_connections.append(self.vpn_connections[vpn_connection_id])
              else:
                  raise InvalidVpnConnectionIdError(vpn_connection_id)
          return vpn_connections or self.vpn_connections.values()
  
      def get_all_vpn_connections(self, vpn_connection_ids=None, filters=None):
          vpn_connections = self.vpn_connections.values()
  
          if vpn_connection_ids:
              vpn_connections = [
                  vpn_connection
                  for vpn_connection in vpn_connections
                  if vpn_connection.id in vpn_connection_ids
              ]
              if len(vpn_connections) != len(vpn_connection_ids):
                  invalid_id = list(
                      set(vpn_connection_ids).difference(
                          set([vpn_connection.id for vpn_connection in vpn_connections])
                      )
                  )[0]
                  raise InvalidVpnConnectionIdError(invalid_id)
  
          return generic_filter(filters, vpn_connections)
  
  
  class NetworkAclBackend(object):
      def __init__(self):
          self.network_acls = {}
          super(NetworkAclBackend, self).__init__()
  
      def get_network_acl(self, network_acl_id):
          network_acl = self.network_acls.get(network_acl_id, None)
          if not network_acl:
              raise InvalidNetworkAclIdError(network_acl_id)
          return network_acl
  
      def create_network_acl(self, vpc_id, tags=[], default=False):
          network_acl_id = random_network_acl_id()
          self.get_vpc(vpc_id)
          network_acl = NetworkAcl(self, network_acl_id, vpc_id, default)
          for tag in tags:
              network_acl.add_tag(tag.get("Key"), tag.get("Value"))
          self.network_acls[network_acl_id] = network_acl
          if default:
              self.add_default_entries(network_acl_id)
          return network_acl
  
      def add_default_entries(self, network_acl_id):
          default_acl_entries = [
              {"rule_number": "100", "rule_action": "allow", "egress": "true"},
              {"rule_number": "32767", "rule_action": "deny", "egress": "true"},
              {"rule_number": "100", "rule_action": "allow", "egress": "false"},
              {"rule_number": "32767", "rule_action": "deny", "egress": "false"},
          ]
          for entry in default_acl_entries:
              self.create_network_acl_entry(
                  network_acl_id=network_acl_id,
                  rule_number=entry["rule_number"],
                  protocol="-1",
                  rule_action=entry["rule_action"],
                  egress=entry["egress"],
                  cidr_block="0.0.0.0/0",
                  icmp_code=None,
                  icmp_type=None,
                  port_range_from=None,
                  port_range_to=None,
              )
  
      def get_all_network_acls(self, network_acl_ids=None, filters=None):
          self.describe_network_acls(network_acl_ids, filters)
  
      def delete_network_acl(self, network_acl_id):
          deleted = self.network_acls.pop(network_acl_id, None)
          if not deleted:
              raise InvalidNetworkAclIdError(network_acl_id)
          return deleted
  
      def create_network_acl_entry(
          self,
          network_acl_id,
          rule_number,
          protocol,
          rule_action,
          egress,
          cidr_block,
          icmp_code,
          icmp_type,
          port_range_from,
          port_range_to,
      ):
  
          network_acl = self.get_network_acl(network_acl_id)
          if any(
              entry.egress == egress and entry.rule_number == rule_number
              for entry in network_acl.network_acl_entries
          ):
              raise NetworkAclEntryAlreadyExistsError(rule_number)
          network_acl_entry = NetworkAclEntry(
              self,
              network_acl_id,
              rule_number,
              protocol,
              rule_action,
              egress,
              cidr_block,
              icmp_code,
              icmp_type,
              port_range_from,
              port_range_to,
          )
  
          network_acl.network_acl_entries.append(network_acl_entry)
          return network_acl_entry
  
      def delete_network_acl_entry(self, network_acl_id, rule_number, egress):
          network_acl = self.get_network_acl(network_acl_id)
          entry = next(
              entry
              for entry in network_acl.network_acl_entries
              if entry.egress == egress and entry.rule_number == rule_number
          )
          if entry is not None:
              network_acl.network_acl_entries.remove(entry)
          return entry
  
      def replace_network_acl_entry(
          self,
          network_acl_id,
          rule_number,
          protocol,
          rule_action,
          egress,
          cidr_block,
          icmp_code,
          icmp_type,
          port_range_from,
          port_range_to,
      ):
  
          self.delete_network_acl_entry(network_acl_id, rule_number, egress)
          network_acl_entry = self.create_network_acl_entry(
              network_acl_id,
              rule_number,
              protocol,
              rule_action,
              egress,
              cidr_block,
              icmp_code,
              icmp_type,
              port_range_from,
              port_range_to,
          )
          return network_acl_entry
  
      def replace_network_acl_association(self, association_id, network_acl_id):
  
          # lookup existing association for subnet and delete it
          default_acl = next(
              value
              for key, value in self.network_acls.items()
              if association_id in value.associations.keys()
          )
  
          subnet_id = None
          for key, value in default_acl.associations.items():
              if key == association_id:
                  subnet_id = default_acl.associations[key].subnet_id
                  del default_acl.associations[key]
                  break
  
          new_assoc_id = random_network_acl_subnet_association_id()
          association = NetworkAclAssociation(
              self, new_assoc_id, subnet_id, network_acl_id
          )
          new_acl = self.get_network_acl(network_acl_id)
          new_acl.associations[new_assoc_id] = association
          return association
  
      def associate_default_network_acl_with_subnet(self, subnet_id, vpc_id):
          association_id = random_network_acl_subnet_association_id()
          acl = next(
              acl
              for acl in self.network_acls.values()
              if acl.default and acl.vpc_id == vpc_id
          )
          acl.associations[association_id] = NetworkAclAssociation(
              self, association_id, subnet_id, acl.id
          )
  
      def describe_network_acls(self, network_acl_ids=None, filters=None):
          network_acls = self.network_acls.values()
  
          if network_acl_ids:
              network_acls = [
                  network_acl
                  for network_acl in network_acls
                  if network_acl.id in network_acl_ids
              ]
              if len(network_acls) != len(network_acl_ids):
                  invalid_id = list(
                      set(network_acl_ids).difference(
                          set([network_acl.id for network_acl in network_acls])
                      )
                  )[0]
                  raise InvalidRouteTableIdError(invalid_id)
  
          return generic_filter(filters, network_acls)
  
  
  class NetworkAclAssociation(object):
      def __init__(self, ec2_backend, new_association_id, subnet_id, network_acl_id):
          self.ec2_backend = ec2_backend
          self.id = new_association_id
          self.new_association_id = new_association_id
          self.subnet_id = subnet_id
          self.network_acl_id = network_acl_id
          super(NetworkAclAssociation, self).__init__()
  
  
  class NetworkAcl(TaggedEC2Resource):
      def __init__(self, ec2_backend, network_acl_id, vpc_id, default=False):
          self.ec2_backend = ec2_backend
          self.id = network_acl_id
          self.vpc_id = vpc_id
          self.network_acl_entries = []
          self.associations = {}
          self.default = "true" if default is True else "false"
  
      def get_filter_value(self, filter_name):
          if filter_name == "default":
              return self.default
          elif filter_name == "vpc-id":
              return self.vpc_id
          elif filter_name == "association.network-acl-id":
              return self.id
          elif filter_name == "association.subnet-id":
              return [assoc.subnet_id for assoc in self.associations.values()]
          else:
              return super(NetworkAcl, self).get_filter_value(
                  filter_name, "DescribeNetworkAcls"
              )
  
  
  class NetworkAclEntry(TaggedEC2Resource):
      def __init__(
          self,
          ec2_backend,
          network_acl_id,
          rule_number,
          protocol,
          rule_action,
          egress,
          cidr_block,
          icmp_code,
          icmp_type,
          port_range_from,
          port_range_to,
      ):
          self.ec2_backend = ec2_backend
          self.network_acl_id = network_acl_id
          self.rule_number = rule_number
          self.protocol = protocol
          self.rule_action = rule_action
          self.egress = egress
          self.cidr_block = cidr_block
          self.icmp_code = icmp_code
          self.icmp_type = icmp_type
          self.port_range_from = port_range_from
          self.port_range_to = port_range_to
  
  
  class VpnGateway(TaggedEC2Resource):
      def __init__(self, ec2_backend, id, type):
          self.ec2_backend = ec2_backend
          self.id = id
          self.type = type
          self.attachments = {}
          super(VpnGateway, self).__init__()
  
      def get_filter_value(self, filter_name):
          if filter_name == "attachment.vpc-id":
              return self.attachments.keys()
          elif filter_name == "attachment.state":
              return [attachment.state for attachment in self.attachments.values()]
          elif filter_name == "vpn-gateway-id":
              return self.id
          elif filter_name == "type":
              return self.type
          return super(VpnGateway, self).get_filter_value(
              filter_name, "DescribeVpnGateways"
          )
  
  
  class VpnGatewayAttachment(object):
      def __init__(self, vpc_id, state):
          self.vpc_id = vpc_id
          self.state = state
          super(VpnGatewayAttachment, self).__init__()
  
  
  class VpnGatewayBackend(object):
      def __init__(self):
          self.vpn_gateways = {}
          super(VpnGatewayBackend, self).__init__()
  
      def create_vpn_gateway(self, type="ipsec.1"):
          vpn_gateway_id = random_vpn_gateway_id()
          vpn_gateway = VpnGateway(self, vpn_gateway_id, type)
          self.vpn_gateways[vpn_gateway_id] = vpn_gateway
          return vpn_gateway
  
      def get_all_vpn_gateways(self, filters=None):
          vpn_gateways = self.vpn_gateways.values()
          return generic_filter(filters, vpn_gateways)
  
      def get_vpn_gateway(self, vpn_gateway_id):
          vpn_gateway = self.vpn_gateways.get(vpn_gateway_id, None)
          if not vpn_gateway:
              raise InvalidVpnGatewayIdError(vpn_gateway_id)
          return vpn_gateway
  
      def attach_vpn_gateway(self, vpn_gateway_id, vpc_id):
          vpn_gateway = self.get_vpn_gateway(vpn_gateway_id)
          self.get_vpc(vpc_id)
          attachment = VpnGatewayAttachment(vpc_id, state="attached")
          vpn_gateway.attachments[vpc_id] = attachment
          return attachment
  
      def delete_vpn_gateway(self, vpn_gateway_id):
          deleted = self.vpn_gateways.pop(vpn_gateway_id, None)
          if not deleted:
              raise InvalidVpnGatewayIdError(vpn_gateway_id)
          return deleted
  
      def detach_vpn_gateway(self, vpn_gateway_id, vpc_id):
          vpn_gateway = self.get_vpn_gateway(vpn_gateway_id)
          self.get_vpc(vpc_id)
          detached = vpn_gateway.attachments.pop(vpc_id, None)
          if not detached:
              raise InvalidVPCIdError(vpc_id)
          return detached
  
  
  class CustomerGateway(TaggedEC2Resource):
      def __init__(self, ec2_backend, id, type, ip_address, bgp_asn):
          self.ec2_backend = ec2_backend
          self.id = id
          self.type = type
          self.ip_address = ip_address
          self.bgp_asn = bgp_asn
          self.attachments = {}
          super(CustomerGateway, self).__init__()
  
      def get_filter_value(self, filter_name):
          return super(CustomerGateway, self).get_filter_value(
              filter_name, "DescribeCustomerGateways"
          )
  
  
  class CustomerGatewayBackend(object):
      def __init__(self):
          self.customer_gateways = {}
          super(CustomerGatewayBackend, self).__init__()
  
      def create_customer_gateway(self, type="ipsec.1", ip_address=None, bgp_asn=None):
          customer_gateway_id = random_customer_gateway_id()
          customer_gateway = CustomerGateway(
              self, customer_gateway_id, type, ip_address, bgp_asn
          )
          self.customer_gateways[customer_gateway_id] = customer_gateway
          return customer_gateway
  
      def get_all_customer_gateways(self, filters=None):
          customer_gateways = self.customer_gateways.values()
          return generic_filter(filters, customer_gateways)
  
      def get_customer_gateway(self, customer_gateway_id):
          customer_gateway = self.customer_gateways.get(customer_gateway_id, None)
          if not customer_gateway:
              raise InvalidCustomerGatewayIdError(customer_gateway_id)
          return customer_gateway
  
      def delete_customer_gateway(self, customer_gateway_id):
          deleted = self.customer_gateways.pop(customer_gateway_id, None)
          if not deleted:
              raise InvalidCustomerGatewayIdError(customer_gateway_id)
          return deleted
  
  
  class NatGateway(CloudFormationModel):
      def __init__(self, backend, subnet_id, allocation_id):
          # public properties
          self.id = random_nat_gateway_id()
          self.subnet_id = subnet_id
          self.allocation_id = allocation_id
          self.state = "available"
          self.private_ip = random_private_ip()
  
          # protected properties
          self._created_at = datetime.utcnow()
          self._backend = backend
          # NOTE: this is the core of NAT Gateways creation
          self._eni = self._backend.create_network_interface(
              backend.get_subnet(self.subnet_id), self.private_ip
          )
  
          # associate allocation with ENI
          self._backend.associate_address(eni=self._eni, allocation_id=self.allocation_id)
  
      @property
      def vpc_id(self):
          subnet = self._backend.get_subnet(self.subnet_id)
          return subnet.vpc_id
  
      @property
      def create_time(self):
          return iso_8601_datetime_with_milliseconds(self._created_at)
  
      @property
      def network_interface_id(self):
          return self._eni.id
  
      @property
      def public_ip(self):
          eips = self._backend.address_by_allocation([self.allocation_id])
          return eips[0].public_ip
  
      @staticmethod
      def cloudformation_name_type():
          return None
  
      @staticmethod
      def cloudformation_type():
          # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-natgateway.html
          return "AWS::EC2::NatGateway"
  
      @classmethod
      def create_from_cloudformation_json(
          cls, resource_name, cloudformation_json, region_name
      ):
          ec2_backend = ec2_backends[region_name]
          nat_gateway = ec2_backend.create_nat_gateway(
              cloudformation_json["Properties"]["SubnetId"],
              cloudformation_json["Properties"]["AllocationId"],
          )
          return nat_gateway
  
  
  class NatGatewayBackend(object):
      def __init__(self):
          self.nat_gateways = {}
          super(NatGatewayBackend, self).__init__()
  
      def get_all_nat_gateways(self, filters):
          nat_gateways = self.nat_gateways.values()
  
          if filters is not None:
              if filters.get("nat-gateway-id") is not None:
                  nat_gateways = [
                      nat_gateway
                      for nat_gateway in nat_gateways
                      if nat_gateway.id in filters["nat-gateway-id"]
                  ]
              if filters.get("vpc-id") is not None:
                  nat_gateways = [
                      nat_gateway
                      for nat_gateway in nat_gateways
                      if nat_gateway.vpc_id in filters["vpc-id"]
                  ]
              if filters.get("subnet-id") is not None:
                  nat_gateways = [
                      nat_gateway
                      for nat_gateway in nat_gateways
                      if nat_gateway.subnet_id in filters["subnet-id"]
                  ]
              if filters.get("state") is not None:
                  nat_gateways = [
                      nat_gateway
                      for nat_gateway in nat_gateways
                      if nat_gateway.state in filters["state"]
                  ]
  
          return nat_gateways
  
      def create_nat_gateway(self, subnet_id, allocation_id):
          nat_gateway = NatGateway(self, subnet_id, allocation_id)
          self.nat_gateways[nat_gateway.id] = nat_gateway
          return nat_gateway
  
      def delete_nat_gateway(self, nat_gateway_id):
          return self.nat_gateways.pop(nat_gateway_id)
  
  
  class LaunchTemplateVersion(object):
      def __init__(self, template, number, data, description):
          self.template = template
          self.number = number
          self.data = data
          self.description = description
          self.create_time = utc_date_and_time()
  
      @property
      def image_id(self):
          return self.data.get("ImageId", "")
  
      @property
      def instance_type(self):
          return self.data.get("InstanceType", "")
  
      @property
      def security_groups(self):
          return self.data.get("SecurityGroups", [])
  
      @property
      def user_data(self):
          return self.data.get("UserData", "")
  
  
  class LaunchTemplate(TaggedEC2Resource):
      def __init__(self, backend, name, template_data, version_description):
          self.ec2_backend = backend
          self.name = name
          self.id = random_launch_template_id()
          self.create_time = utc_date_and_time()
  
          self.versions = []
          self.create_version(template_data, version_description)
          self.default_version_number = 1
  
      def create_version(self, data, description):
          num = len(self.versions) + 1
          version = LaunchTemplateVersion(self, num, data, description)
          self.versions.append(version)
          return version
  
      def is_default(self, version):
          return self.default_version == version.number
  
      def get_version(self, num):
          return self.versions[num - 1]
  
      def default_version(self):
          return self.versions[self.default_version_number - 1]
  
      def latest_version(self):
          return self.versions[-1]
  
      @property
      def latest_version_number(self):
          return self.latest_version().number
  
      def get_filter_value(self, filter_name):
          if filter_name == "launch-template-name":
              return self.name
          else:
              return super(LaunchTemplate, self).get_filter_value(
                  filter_name, "DescribeLaunchTemplates"
              )
  
  
  class LaunchTemplateBackend(object):
      def __init__(self):
          self.launch_template_name_to_ids = {}
          self.launch_templates = OrderedDict()
          self.launch_template_insert_order = []
          super(LaunchTemplateBackend, self).__init__()
  
      def create_launch_template(self, name, description, template_data):
          if name in self.launch_template_name_to_ids:
              raise InvalidLaunchTemplateNameError()
          template = LaunchTemplate(self, name, template_data, description)
          self.launch_templates[template.id] = template
          self.launch_template_name_to_ids[template.name] = template.id
          self.launch_template_insert_order.append(template.id)
          return template
  
      def get_launch_template(self, template_id):
          return self.launch_templates[template_id]
  
      def get_launch_template_by_name(self, name):
          return self.get_launch_template(self.launch_template_name_to_ids[name])
  
      def get_launch_templates(
          self, template_names=None, template_ids=None, filters=None
      ):
          if template_names and not template_ids:
              template_ids = []
              for name in template_names:
                  template_ids.append(self.launch_template_name_to_ids[name])
  
          if template_ids:
              templates = [self.launch_templates[tid] for tid in template_ids]
          else:
              templates = list(self.launch_templates.values())
  
          return generic_filter(filters, templates)
  
  
  class EC2Backend(
      BaseBackend,
      InstanceBackend,
      TagBackend,
      EBSBackend,
      RegionsAndZonesBackend,
      SecurityGroupBackend,
      AmiBackend,
      VPCBackend,
      SubnetBackend,
      SubnetRouteTableAssociationBackend,
      FlowLogsBackend,
      NetworkInterfaceBackend,
      VPNConnectionBackend,
      VPCPeeringConnectionBackend,
      RouteTableBackend,
      RouteBackend,
      InternetGatewayBackend,
      VPCGatewayAttachmentBackend,
      SpotFleetBackend,
      SpotRequestBackend,
      ElasticAddressBackend,
      KeyPairBackend,
      DHCPOptionsSetBackend,
      NetworkAclBackend,
      VpnGatewayBackend,
      CustomerGatewayBackend,
      NatGatewayBackend,
      LaunchTemplateBackend,
  ):
      def __init__(self, region_name):
          self.region_name = region_name
          super(EC2Backend, self).__init__()
  
          # Default VPC exists by default, which is the current behavior
          # of EC2-VPC. See for detail:
          #
          #   docs.aws.amazon.com/AmazonVPC/latest/UserGuide/default-vpc.html
          #
          if not self.vpcs:
              vpc = self.create_vpc("172.31.0.0/16")
          else:
              # For now this is included for potential
              # backward-compatibility issues
              vpc = self.vpcs.values()[0]
  
          # Create default subnet for each availability zone
          ip, _ = vpc.cidr_block.split("/")
          ip = ip.split(".")
          ip[2] = 0
  
          for zone in self.describe_availability_zones():
              az_name = zone.name
              cidr_block = ".".join(str(i) for i in ip) + "/20"
              self.create_subnet(vpc.id, cidr_block, availability_zone=az_name)
              ip[2] += 16
  
      def reset(self):
          region_name = self.region_name
          self.__dict__ = {}
          self.__init__(region_name)
  
      # Use this to generate a proper error template response when in a response
      # handler.
      def raise_error(self, code, message):
          raise EC2ClientError(code, message)
  
      def raise_not_implemented_error(self, blurb):
          raise MotoNotImplementedError(blurb)
  
      def do_resources_exist(self, resource_ids):
          for resource_id in resource_ids:
              resource_prefix = get_prefix(resource_id)
              if resource_prefix == EC2_RESOURCE_TO_PREFIX["customer-gateway"]:
                  self.get_customer_gateway(customer_gateway_id=resource_id)
              elif resource_prefix == EC2_RESOURCE_TO_PREFIX["dhcp-options"]:
                  self.describe_dhcp_options(options_ids=[resource_id])
              elif resource_prefix == EC2_RESOURCE_TO_PREFIX["image"]:
                  self.describe_images(ami_ids=[resource_id])
              elif resource_prefix == EC2_RESOURCE_TO_PREFIX["instance"]:
                  self.get_instance_by_id(instance_id=resource_id)
              elif resource_prefix == EC2_RESOURCE_TO_PREFIX["internet-gateway"]:
                  self.describe_internet_gateways(internet_gateway_ids=[resource_id])
              elif resource_prefix == EC2_RESOURCE_TO_PREFIX["launch-template"]:
                  self.get_launch_template(resource_id)
              elif resource_prefix == EC2_RESOURCE_TO_PREFIX["network-acl"]:
                  self.get_all_network_acls()
              elif resource_prefix == EC2_RESOURCE_TO_PREFIX["network-interface"]:
                  self.describe_network_interfaces(
                      filters={"network-interface-id": resource_id}
                  )
              elif resource_prefix == EC2_RESOURCE_TO_PREFIX["reserved-instance"]:
                  self.raise_not_implemented_error("DescribeReservedInstances")
              elif resource_prefix == EC2_RESOURCE_TO_PREFIX["route-table"]:
                  self.get_route_table(route_table_id=resource_id)
              elif resource_prefix == EC2_RESOURCE_TO_PREFIX["security-group"]:
                  self.describe_security_groups(group_ids=[resource_id])
              elif resource_prefix == EC2_RESOURCE_TO_PREFIX["snapshot"]:
                  self.get_snapshot(snapshot_id=resource_id)
              elif resource_prefix == EC2_RESOURCE_TO_PREFIX["spot-instance-request"]:
                  self.describe_spot_instance_requests(
                      filters={"spot-instance-request-id": resource_id}
                  )
              elif resource_prefix == EC2_RESOURCE_TO_PREFIX["subnet"]:
                  self.get_subnet(subnet_id=resource_id)
              elif resource_prefix == EC2_RESOURCE_TO_PREFIX["volume"]:
                  self.get_volume(volume_id=resource_id)
              elif resource_prefix == EC2_RESOURCE_TO_PREFIX["vpc"]:
                  self.get_vpc(vpc_id=resource_id)
              elif resource_prefix == EC2_RESOURCE_TO_PREFIX["vpc-peering-connection"]:
                  self.get_vpc_peering_connection(vpc_pcx_id=resource_id)
              elif resource_prefix == EC2_RESOURCE_TO_PREFIX["vpn-connection"]:
                  self.describe_vpn_connections(vpn_connection_ids=[resource_id])
              elif resource_prefix == EC2_RESOURCE_TO_PREFIX["vpn-gateway"]:
                  self.get_vpn_gateway(vpn_gateway_id=resource_id)
          return True
  
  
  ec2_backends = {
      region.name: EC2Backend(region.name) for region in RegionsAndZonesBackend.regions
  }
  