text: # Copyright 2015 Hewlett-Packard Development Company, L.P.
  #
  # Licensed under the Apache License, Version 2.0 (the "License"); you may
  # not use this file except in compliance with the License. You may obtain
  # a copy of the License at
  #
  # http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  # License for the specific language governing permissions and limitations
  # under the License.
  
  import hashlib
  import io
  import os
  import re
  import shutil
  import stat
  import subprocess
  
  import flask
  import jinja2
  from oslo_config import cfg
  from oslo_log import log as logging
  import six
  import webob
  from werkzeug import exceptions
  
  from octavia.amphorae.backends.agent.api_server import haproxy_compatibility
  from octavia.amphorae.backends.agent.api_server import osutils
  from octavia.amphorae.backends.agent.api_server import util
  from octavia.amphorae.backends.utils import haproxy_query as query
  from octavia.common import constants as consts
  from octavia.common import utils as octavia_utils
  
  LOG = logging.getLogger(__name__)
  BUFFER = 100
  
  CONF = cfg.CONF
  
  UPSTART_CONF = 'upstart.conf.j2'
  SYSVINIT_CONF = 'sysvinit.conf.j2'
  SYSTEMD_CONF = 'systemd.conf.j2'
  AMPHORA_NETNS = 'amphora-netns'
  
  JINJA_ENV = jinja2.Environment(
      autoescape=True,
      loader=jinja2.FileSystemLoader(os.path.dirname(
          os.path.realpath(__file__)
      ) + consts.AGENT_API_TEMPLATES))
  UPSTART_TEMPLATE = JINJA_ENV.get_template(UPSTART_CONF)
  SYSVINIT_TEMPLATE = JINJA_ENV.get_template(SYSVINIT_CONF)
  SYSTEMD_TEMPLATE = JINJA_ENV.get_template(SYSTEMD_CONF)
  
  
  class ParsingError(Exception):
      pass
  
  
  # Wrap a stream so we can compute the md5 while reading
  class Wrapped(object):
      def __init__(self, stream_):
          self.stream = stream_
          self.hash = hashlib.md5()  # nosec
  
      def read(self, l):
          block = self.stream.read(l)
          if block:
              self.hash.update(block)
          return block
  
      def get_md5(self):
          return self.hash.hexdigest()
  
      def __getattr__(self, attr):
          return getattr(self.stream, attr)
  
  
  class Listener(object):
  
      def __init__(self):
          self._osutils = osutils.BaseOS.get_os_util()
  
      def get_haproxy_config(self, listener_id):
          """Gets the haproxy config
  
          :param listener_id: the id of the listener
          """
          self._check_listener_exists(listener_id)
          with open(util.config_path(listener_id), 'r') as file:
              cfg = file.read()
              resp = webob.Response(cfg, content_type='text/plain')
              resp.headers['ETag'] = hashlib.md5(six.b(cfg)).hexdigest()  # nosec
              return resp
  
      def upload_haproxy_config(self, amphora_id, listener_id):
          """Upload the haproxy config
  
          :param amphora_id: The id of the amphora to update
          :param listener_id: The id of the listener
          """
          stream = Wrapped(flask.request.stream)
          # We have to hash here because HAProxy has a string length limitation
          # in the configuration file "peer <peername>" lines
          peer_name = octavia_utils.base64_sha1_string(amphora_id).rstrip('=')
          if not os.path.exists(util.haproxy_dir(listener_id)):
              os.makedirs(util.haproxy_dir(listener_id))
  
          name = os.path.join(util.haproxy_dir(listener_id), 'haproxy.cfg.new')
          flags = os.O_WRONLY | os.O_CREAT | os.O_TRUNC
          # mode 00600
          mode = stat.S_IRUSR | stat.S_IWUSR
          b = stream.read(BUFFER)
          s_io = io.StringIO()
          while b:
              # Write haproxy configuration to StringIO
              s_io.write(b.decode('utf8'))
              b = stream.read(BUFFER)
  
          # Since haproxy user_group is now auto-detected by the amphora agent,
          # remove it from haproxy configuration in case it was provided
          # by an older Octavia controller. This is needed in order to prevent
          # a duplicate entry for 'group' in haproxy configuration, which will
          # result an error when haproxy starts.
          new_config = re.sub(r"\s+group\s.+", "", s_io.getvalue())
  
          # Handle any haproxy version compatibility issues
          new_config = haproxy_compatibility.process_cfg_for_version_compat(
              new_config)
  
          with os.fdopen(os.open(name, flags, mode), 'w') as file:
              file.write(new_config)
  
          # use haproxy to check the config
          cmd = "haproxy -c -L {peer} -f {config_file} -f {haproxy_ug}".format(
              config_file=name, peer=peer_name,
              haproxy_ug=consts.HAPROXY_USER_GROUP_CFG)
  
          try:
              subprocess.check_output(cmd.split(), stderr=subprocess.STDOUT)
          except subprocess.CalledProcessError as e:
              LOG.error("Failed to verify haproxy file: %s %s", e, e.output)
              # Save the last config that failed validation for debugging
              os.rename(name, ''.join([name, '-failed']))
              return webob.Response(
                  json=dict(message="Invalid request", details=e.output),
                  status=400)
  
          # file ok - move it
          os.rename(name, util.config_path(listener_id))
  
          try:
  
              init_system = util.get_os_init_system()
  
              LOG.debug('Found init system: %s', init_system)
  
              init_path = util.init_path(listener_id, init_system)
  
              if init_system == consts.INIT_SYSTEMD:
                  template = SYSTEMD_TEMPLATE
                  init_enable_cmd = "systemctl enable haproxy-{list}".format(
                                    list=listener_id)
              elif init_system == consts.INIT_UPSTART:
                  template = UPSTART_TEMPLATE
              elif init_system == consts.INIT_SYSVINIT:
                  template = SYSVINIT_TEMPLATE
                  init_enable_cmd = "insserv {file}".format(file=init_path)
              else:
                  raise util.UnknownInitError()
  
          except util.UnknownInitError:
              LOG.error("Unknown init system found.")
              return webob.Response(json=dict(
                  message="Unknown init system in amphora",
                  details="The amphora image is running an unknown init "
                          "system.  We can't create the init configuration "
                          "file for the load balancing process."), status=500)
  
          if init_system == consts.INIT_SYSTEMD:
              # mode 00644
              mode = (stat.S_IRUSR | stat.S_IWUSR | stat.S_IRGRP | stat.S_IROTH)
          else:
              # mode 00755
              mode = (stat.S_IRWXU | stat.S_IRGRP | stat.S_IXGRP |
                      stat.S_IROTH | stat.S_IXOTH)
  
          if init_system == consts.INIT_SYSTEMD:
              # TODO(bcafarel): implement this for other init systems
              # netns handling depends on a separate unit file
              netns_path = os.path.join(consts.SYSTEMD_DIR,
                                        AMPHORA_NETNS + '.service')
              if not os.path.exists(netns_path):
                  with os.fdopen(os.open(netns_path, flags, mode),
                                 'w') as text_file:
                      text = JINJA_ENV.get_template(
                          AMPHORA_NETNS + '.systemd.j2').render(
                              amphora_nsname=consts.AMPHORA_NAMESPACE,
                              HasIFUPAll=self._osutils.has_ifup_all())
                      text_file.write(text)
  
          hap_major, hap_minor = haproxy_compatibility.get_haproxy_versions()
          if not os.path.exists(init_path):
              with os.fdopen(os.open(init_path, flags, mode), 'w') as text_file:
  
                  text = template.render(
                      peer_name=peer_name,
                      haproxy_pid=util.pid_path(listener_id),
                      haproxy_cmd=util.CONF.haproxy_amphora.haproxy_cmd,
                      haproxy_cfg=util.config_path(listener_id),
                      haproxy_user_group_cfg=consts.HAPROXY_USER_GROUP_CFG,
                      respawn_count=util.CONF.haproxy_amphora.respawn_count,
                      respawn_interval=(util.CONF.haproxy_amphora.
                                        respawn_interval),
                      amphora_netns=AMPHORA_NETNS,
                      amphora_nsname=consts.AMPHORA_NAMESPACE,
                      HasIFUPAll=self._osutils.has_ifup_all(),
                      haproxy_major_version=hap_major,
                      haproxy_minor_version=hap_minor
                  )
                  text_file.write(text)
  
          # Make sure the new service is enabled on boot
          if init_system != consts.INIT_UPSTART:
              try:
                  subprocess.check_output(init_enable_cmd.split(),
                                          stderr=subprocess.STDOUT)
              except subprocess.CalledProcessError as e:
                  LOG.error("Failed to enable haproxy-%(list)s service: "
                            "%(err)s %(out)s", {'list': listener_id, 'err': e,
                                                'out': e.output})
                  return webob.Response(json=dict(
                      message="Error enabling haproxy-{0} service".format(
                              listener_id), details=e.output), status=500)
  
          res = webob.Response(json={'message': 'OK'}, status=202)
          res.headers['ETag'] = stream.get_md5()
  
          return res
  
      def start_stop_listener(self, listener_id, action):
          action = action.lower()
          if action not in [consts.AMP_ACTION_START,
                            consts.AMP_ACTION_STOP,
                            consts.AMP_ACTION_RELOAD]:
              return webob.Response(json=dict(
                  message='Invalid Request',
                  details="Unknown action: {0}".format(action)), status=400)
  
          self._check_listener_exists(listener_id)
  
          # Since this script should be created at LB create time
          # we can check for this path to see if VRRP is enabled
          # on this amphora and not write the file if VRRP is not in use
          if os.path.exists(util.keepalived_check_script_path()):
              self.vrrp_check_script_update(listener_id, action)
  
          # HAProxy does not start the process when given a reload
          # so start it if haproxy is not already running
          if action == consts.AMP_ACTION_RELOAD:
              if consts.OFFLINE == self._check_haproxy_status(listener_id):
                  action = consts.AMP_ACTION_START
  
          cmd = ("/usr/sbin/service haproxy-{listener_id} {action}".format(
              listener_id=listener_id, action=action))
  
          try:
              subprocess.check_output(cmd.split(), stderr=subprocess.STDOUT)
          except subprocess.CalledProcessError as e:
              if 'Job is already running' not in e.output:
                  LOG.debug(
                      "Failed to %(action)s haproxy-%(list)s service: %(err)s "
                      "%(out)s", {'action': action, 'list': listener_id,
                                  'err': e, 'out': e.output})
                  return webob.Response(json=dict(
                      message="Error {0}ing haproxy".format(action),
                      details=e.output), status=500)
          if action in [consts.AMP_ACTION_STOP,
                        consts.AMP_ACTION_RELOAD]:
              return webob.Response(json=dict(
                  message='OK',
                  details='Listener {listener_id} {action}ed'.format(
                      listener_id=listener_id, action=action)), status=202)
  
          details = (
              'Configuration file is valid\n'
              'haproxy daemon for {0} started'.format(listener_id)
          )
  
          return webob.Response(json=dict(message='OK', details=details),
                                status=202)
  
      def delete_listener(self, listener_id):
          try:
              self._check_listener_exists(listener_id)
          except exceptions.HTTPException:
              return webob.Response(json={'message': 'OK'})
  
          # check if that haproxy is still running and if stop it
          if os.path.exists(util.pid_path(listener_id)) and os.path.exists(
                  os.path.join('/proc', util.get_haproxy_pid(listener_id))):
              cmd = "/usr/sbin/service haproxy-{0} stop".format(listener_id)
              try:
                  subprocess.check_output(cmd.split(), stderr=subprocess.STDOUT)
              except subprocess.CalledProcessError as e:
                  LOG.error("Failed to stop haproxy-%s service: %s %s",
                            listener_id, e, e.output)
                  return webob.Response(json=dict(
                      message="Error stopping haproxy",
                      details=e.output), status=500)
  
          # parse config and delete stats socket
          try:
              cfg = self._parse_haproxy_file(listener_id)
              os.remove(cfg['stats_socket'])
          except Exception:
              pass
  
          # Since this script should be deleted at LB delete time
          # we can check for this path to see if VRRP is enabled
          # on this amphora and not write the file if VRRP is not in use
          if os.path.exists(util.keepalived_check_script_path()):
              self.vrrp_check_script_update(
                  listener_id, action=consts.AMP_ACTION_STOP)
  
          # delete the ssl files
          try:
              shutil.rmtree(self._cert_dir(listener_id))
          except Exception:
              pass
  
          # disable the service
          init_system = util.get_os_init_system()
          init_path = util.init_path(listener_id, init_system)
  
          if init_system == consts.INIT_SYSTEMD:
              init_disable_cmd = "systemctl disable haproxy-{list}".format(
                                 list=listener_id)
          elif init_system == consts.INIT_SYSVINIT:
              init_disable_cmd = "insserv -r {file}".format(file=init_path)
          elif init_system != consts.INIT_UPSTART:
              raise util.UnknownInitError()
  
          if init_system != consts.INIT_UPSTART:
              try:
                  subprocess.check_output(init_disable_cmd.split(),
                                          stderr=subprocess.STDOUT)
              except subprocess.CalledProcessError as e:
                  LOG.error("Failed to disable haproxy-%(list)s service: "
                            "%(err)s %(out)s", {'list': listener_id, 'err': e,
                                                'out': e.output})
                  return webob.Response(json=dict(
                      message="Error disabling haproxy-{0} service".format(
                              listener_id), details=e.output), status=500)
  
          # delete the directory + init script for that listener
          shutil.rmtree(util.haproxy_dir(listener_id))
          if os.path.exists(init_path):
              os.remove(init_path)
  
          return webob.Response(json={'message': 'OK'})
  
      def get_all_listeners_status(self):
          """Gets the status of all listeners
  
          This method will not consult the stats socket
          so a listener might show as ACTIVE but still be
          in ERROR
  
          Currently type==SSL is also not detected
          """
          listeners = list()
  
          for listener in util.get_listeners():
              status = self._check_listener_status(listener)
              listener_type = ''
  
              if status == consts.ACTIVE:
                  listener_type = self._parse_haproxy_file(listener)['mode']
  
              listeners.append({
                  'status': status,
                  'uuid': listener,
                  'type': listener_type,
              })
  
          return webob.Response(json=listeners, content_type='application/json')
  
      def get_listener_status(self, listener_id):
          """Gets the status of a listener
  
          This method will consult the stats socket
          so calling this method will interfere with
          the health daemon with the risk of the amphora
          shut down
  
          Currently type==SSL is not detected
          :param listener_id: The id of the listener
          """
          self._check_listener_exists(listener_id)
  
          status = self._check_listener_status(listener_id)
  
          if status != consts.ACTIVE:
              stats = dict(
                  status=status,
                  uuid=listener_id,
                  type=''
              )
              return webob.Response(json=stats)
  
          cfg = self._parse_haproxy_file(listener_id)
          stats = dict(
              status=status,
              uuid=listener_id,
              type=cfg['mode']
          )
  
          # read stats socket
          q = query.HAProxyQuery(cfg['stats_socket'])
          servers = q.get_pool_status()
          stats['pools'] = list(servers.values())
          return webob.Response(json=stats)
  
      def upload_certificate(self, listener_id, filename):
          self._check_ssl_filename_format(filename)
  
          # create directory if not already there
          if not os.path.exists(self._cert_dir(listener_id)):
              os.makedirs(self._cert_dir(listener_id))
  
          stream = Wrapped(flask.request.stream)
          file = self._cert_file_path(listener_id, filename)
          flags = os.O_WRONLY | os.O_CREAT
          # mode 00600
          mode = stat.S_IRUSR | stat.S_IWUSR
          with os.fdopen(os.open(file, flags, mode), 'wb') as crt_file:
              b = stream.read(BUFFER)
              while b:
                  crt_file.write(b)
                  b = stream.read(BUFFER)
  
          resp = webob.Response(json=dict(message='OK'))
          resp.headers['ETag'] = stream.get_md5()
          return resp
  
      def get_certificate_md5(self, listener_id, filename):
          self._check_ssl_filename_format(filename)
  
          cert_path = self._cert_file_path(listener_id, filename)
          path_exists = os.path.exists(cert_path)
          if not path_exists:
              return webob.Response(json=dict(
                  message='Certificate Not Found',
                  details="No certificate with filename: {f}".format(
                      f=filename)), status=404)
  
          with open(cert_path, 'r') as crt_file:
              cert = crt_file.read()
              md5 = hashlib.md5(six.b(cert)).hexdigest()  # nosec
              resp = webob.Response(json=dict(md5sum=md5))
              resp.headers['ETag'] = md5
              return resp
  
      def delete_certificate(self, listener_id, filename):
          self._check_ssl_filename_format(filename)
          if os.path.exists(self._cert_file_path(listener_id, filename)):
              os.remove(self._cert_file_path(listener_id, filename))
          return webob.Response(json=dict(message='OK'))
  
      def _check_listener_status(self, listener_id):
          if os.path.exists(util.pid_path(listener_id)):
              if os.path.exists(
                      os.path.join('/proc', util.get_haproxy_pid(listener_id))):
                  # Check if the listener is disabled
                  with open(util.config_path(listener_id), 'r') as file:
                      cfg = file.read()
                      m = re.search('frontend {}'.format(listener_id), cfg)
                      if m:
                          return consts.ACTIVE
                      else:
                          return consts.OFFLINE
              else:  # pid file but no process...
                  return consts.ERROR
          else:
              return consts.OFFLINE
  
      def _parse_haproxy_file(self, listener_id):
          with open(util.config_path(listener_id), 'r') as file:
              cfg = file.read()
  
              m = re.search('mode\s+(http|tcp)', cfg)
              if not m:
                  raise ParsingError()
              mode = m.group(1).upper()
  
              m = re.search('stats socket\s+(\S+)', cfg)
              if not m:
                  raise ParsingError()
              stats_socket = m.group(1)
  
              m = re.search('ssl crt\s+(\S+)', cfg)
              ssl_crt = None
              if m:
                  ssl_crt = m.group(1)
                  mode = 'TERMINATED_HTTPS'
  
              return dict(mode=mode,
                          stats_socket=stats_socket,
                          ssl_crt=ssl_crt)
  
      def _check_listener_exists(self, listener_id):
          # check if we know about that listener
          if not os.path.exists(util.config_path(listener_id)):
              raise exceptions.HTTPException(
                  response=webob.Response(json=dict(
                      message='Listener Not Found',
                      details="No listener with UUID: {0}".format(
                          listener_id)), status=404))
  
      def _check_ssl_filename_format(self, filename):
          # check if the format is (xxx.)*xxx.pem
          if not re.search('(\w.)+pem', filename):
              raise exceptions.HTTPException(
                  response=webob.Response(json=dict(
                      message='Filename has wrong format'), status=400))
  
      def _cert_dir(self, listener_id):
          return os.path.join(util.CONF.haproxy_amphora.base_cert_dir,
                              listener_id)
  
      def _cert_file_path(self, listener_id, filename):
          return os.path.join(self._cert_dir(listener_id), filename)
  
      def vrrp_check_script_update(self, listener_id, action):
          listener_ids = util.get_listeners()
          if action == consts.AMP_ACTION_STOP:
              listener_ids.remove(listener_id)
          args = []
          for listener_id in listener_ids:
              args.append(util.haproxy_sock_path(listener_id))
  
          if not os.path.exists(util.keepalived_dir()):
              os.makedirs(util.keepalived_dir())
              os.makedirs(util.keepalived_check_scripts_dir())
  
          cmd = 'haproxy-vrrp-check {args}; exit $?'.format(args=' '.join(args))
          with open(util.haproxy_check_script_path(), 'w') as text_file:
              text_file.write(cmd)
  
      def _check_haproxy_status(self, listener_id):
          if os.path.exists(util.pid_path(listener_id)):
              if os.path.exists(
                      os.path.join('/proc', util.get_haproxy_pid(listener_id))):
                  return consts.ACTIVE
              else:  # pid file but no process...
                  return consts.OFFLINE
          else:
              return consts.OFFLINE
  