text: # Copyright 2018 The Chromium Authors. All rights reserved.
  # Use of this source code is governed by a BSD-style license that can be
  # found in the LICENSE file.
  
  """Implements commands for running and interacting with Fuchsia on devices."""
  
  from __future__ import print_function
  
  import amber_repo
  import boot_data
  import filecmp
  import logging
  import os
  import re
  import subprocess
  import sys
  import target
  import tempfile
  import time
  import uuid
  
  from common import SDK_ROOT, EnsurePathExists, GetHostToolPathFromPlatform
  
  # The maximum times to attempt mDNS resolution when connecting to a freshly
  # booted Fuchsia instance before aborting.
  _BOOT_DISCOVERY_ATTEMPTS = 30
  
  # Number of seconds to wait when querying a list of all devices over mDNS.
  _LIST_DEVICES_TIMEOUT_SECS = 3
  
  #Number of failed connection attempts before redirecting system logs to stdout.
  CONNECT_RETRY_COUNT_BEFORE_LOGGING = 10
  
  TARGET_HASH_FILE_PATH = '/data/.hash'
  
  class DeviceTarget(target.Target):
    """Prepares a device to be used as a deployment target. Depending on the
    command line parameters, it automatically handling a number of preparatory
    steps relating to address resolution, device provisioning, and SDK
    versioning.
  
    If |_node_name| is unset:
      If there is one running device, use it for deployment and execution. The
      device's SDK version is checked unless --os-check=ignore is set.
      If --os-check=update is set, then the target device is repaved if the SDK
      version doesn't match.
  
      If there are more than one running devices, then abort and instruct the
      user to re-run the command with |_node_name|
  
      Otherwise, if there are no running devices, then search for a device
      running Zedboot, and pave it.
  
  
    If |_node_name| is set:
      If there is a running device with a matching nodename, then it is used
      for deployment and execution.
  
      Otherwise, attempt to pave a device with a matching nodename, and use it
      for deployment and execution.
  
    If |_host| is set:
      Deploy to a device at the host IP address as-is."""
  
    def __init__(self, output_dir, target_cpu, host=None, node_name=None,
                 port=None, ssh_config=None, fuchsia_out_dir=None,
                 os_check='update', system_log_file=None):
      """output_dir: The directory which will contain the files that are
                     generated to support the deployment.
      target_cpu: The CPU architecture of the deployment target. Can be
                  "x64" or "arm64".
      host: The address of the deployment target device.
      node_name: The node name of the deployment target device.
      port: The port of the SSH service on the deployment target device.
      ssh_config: The path to SSH configuration data.
      fuchsia_out_dir: The path to a Fuchsia build output directory, for
                       deployments to devices paved with local Fuchsia builds.
      os_check: If 'check', the target's SDK version must match.
                If 'update', the target will be repaved if the SDK versions
                    mismatch.
                If 'ignore', the target's SDK version is ignored."""
  
      super(DeviceTarget, self).__init__(output_dir, target_cpu)
  
      self._port = port if port else 22
      self._system_log_file = system_log_file
      self._loglistener = None
      self._host = host
      self._fuchsia_out_dir = os.path.expanduser(fuchsia_out_dir)
      self._node_name = node_name
      self._os_check = os_check,
  
      if self._host and self._node_name:
        raise Exception('Only one of "--host" or "--name" can be specified.')
  
      if self._fuchsia_out_dir:
        if ssh_config:
          raise Exception('Only one of "--fuchsia-out-dir" or "--ssh_config" can '
                          'be specified.')
  
        # Use SSH keys from the Fuchsia output directory.
        self._ssh_config_path = os.path.join(self._fuchsia_out_dir, 'ssh-keys',
                                             'ssh_config')
        self._os_check = 'ignore'
  
      elif ssh_config:
        # Use the SSH config provided via the commandline.
        self._ssh_config_path = os.path.expanduser(ssh_config)
  
      else:
        # Default to using an automatically generated SSH config and keys.
        boot_data.ProvisionSSH(output_dir)
        self._ssh_config_path = boot_data.GetSSHConfigPath(output_dir)
  
    def __exit__(self, exc_type, exc_val, exc_tb):
      if self._loglistener:
        self._loglistener.kill()
  
    def _SDKHashMatches(self):
      """Checks if /data/.hash on the device matches SDK_ROOT/.hash.
  
      Returns True if the files are identical, or False otherwise.
      """
      with tempfile.NamedTemporaryFile() as tmp:
        try:
          self.GetFile(TARGET_HASH_FILE_PATH, tmp.name)
        except subprocess.CalledProcessError:
          # If the file is unretrievable for whatever reason, assume mismatch.
          return False
  
        return filecmp.cmp(tmp.name, os.path.join(SDK_ROOT, '.hash'), False)
  
    def __Discover(self):
      """Queries mDNS for the IP address of a booted Fuchsia instance whose name
      matches |_node_name| on the local area network. If |_node_name| isn't
      specified, and there is only one device on the network, then returns the
      IP address of that advice.
  
      Sets |_host_name| and returns True if the device was found,
      or waits up to |timeout| seconds and returns False if the device couldn't
      be found."""
  
      dev_finder_path = GetHostToolPathFromPlatform('dev_finder')
  
      if self._node_name:
        command = [dev_finder_path, 'resolve',
                   '-device-limit', '1',  # Exit early as soon as a host is found.
                   self._node_name]
      else:
        command = [dev_finder_path, 'list', '-full',
                   '-timeout', str(_LIST_DEVICES_TIMEOUT_SECS * 1000)]
  
      proc = subprocess.Popen(command,
                              stdout=subprocess.PIPE,
                              stderr=open(os.devnull, 'w'))
  
      output = set(proc.communicate()[0].strip().split('\n'))
  
      if proc.returncode != 0:
        return False
  
      if self._node_name:
        # Handle the result of "dev_finder resolve".
        self._host = output.pop().strip()
  
      else:
        name_host_pairs = [x.strip().split(' ') for x in output]
  
        # Handle the output of "dev_finder list".
        if len(name_host_pairs) > 1:
          print('More than one device was discovered on the network.')
          print('Use --node-name <name> to specify the device to use.')
          print('\nList of devices:')
          for pair in name_host_pairs:
            print('  ' + pair[1])
          print()
          raise Exception('Ambiguous target device specification.')
  
        assert len(name_host_pairs) == 1
        self._host, self._node_name = name_host_pairs[0]
  
      logging.info('Found device "%s" at address %s.' % (self._node_name,
                                                         self._host))
  
      return True
  
    def Start(self):
      if self._host:
        self._WaitUntilReady()
  
      else:
        should_provision = False
  
        if self.__Discover():
          self._WaitUntilReady()
  
          if self._os_check != 'ignore':
            if self._SDKHashMatches():
              if self._os_check == 'update':
                logging.info( 'SDK hash does not match; rebooting and repaving.')
                self.RunCommand(['dm', 'reboot'])
                should_provision = True
              elif self._os_check == 'check':
                raise Exception('Target device SDK version does not match.')
  
        else:
          should_provision = True
  
        if should_provision:
          boot_data.AssertBootImagesExist(self._GetTargetSdkArch(), 'generic')
          self.__ProvisionDevice()
  
        assert self._node_name
        assert self._host
  
  
    def _GetAmberRepo(self):
      if self._fuchsia_out_dir:
        # Deploy to an already-booted device running a local Fuchsia build.
        return amber_repo.ExternalAmberRepo(
            os.path.join(self._fuchsia_out_dir, 'amber-files'))
      else:
        # Pave a Zedbootable device.
        return amber_repo.ManagedAmberRepo(self)
  
    def __ProvisionDevice(self):
      """Netboots a device with Fuchsia. If |_node_name| is set, then only a
      device with a matching node name is used.
  
      The device is up and reachable via SSH when the function is successfully
      completes."""
  
      bootserver_path = GetHostToolPathFromPlatform('bootserver')
      bootserver_command = [
          bootserver_path,
          '-1',
          '--fvm',
          EnsurePathExists(
              boot_data.GetTargetFile('storage-sparse.blk',
                                      self._GetTargetSdkArch(),
                                      boot_data.TARGET_TYPE_GENERIC)),
          EnsurePathExists(boot_data.GetBootImage(self._output_dir,
                                                  self._GetTargetSdkArch(),
                                                  boot_data.TARGET_TYPE_GENERIC))]
  
      if self._node_name:
        bootserver_command += ['-n', self._node_name]
  
      bootserver_command += ['--']
      bootserver_command += boot_data.GetKernelArgs(self._output_dir)
  
      logging.debug(' '.join(bootserver_command))
      stdout = subprocess.check_output(bootserver_command,
                                       stderr=subprocess.STDOUT)
  
      # Parse the nodename from bootserver stdout.
      m = re.search(r'.*Proceeding with nodename (?P<nodename>.*)$', stdout,
                    re.MULTILINE)
      if not m:
        raise Exception('Couldn\'t parse nodename from bootserver output.')
      self._node_name = m.groupdict()['nodename']
      logging.info('Booted device "%s".' % self._node_name)
  
      # Start loglistener to save system logs.
      if self._system_log_file:
        loglistener_path = GetHostToolPathFromPlatform('loglistener')
        self._loglistener = subprocess.Popen(
            [loglistener_path, self._node_name],
            stdout=self._system_log_file,
            stderr=subprocess.STDOUT, stdin=open(os.devnull))
  
      # Repeatdly query mDNS until we find the device, or we hit the timeout of
      # DISCOVERY_TIMEOUT_SECS.
      logging.info('Waiting for device to join network.')
      for _ in xrange(_BOOT_DISCOVERY_ATTEMPTS):
        if self.__Discover():
          break
  
      if not self._host:
        raise Exception('Device %s couldn\'t be discovered via mDNS.' %
                        self._node_name)
  
      self._WaitUntilReady();
  
      # Update the target's hash to match the current tree's.
      self.PutFile(os.path.join(SDK_ROOT, '.hash'), TARGET_HASH_FILE_PATH)
  
    def _GetEndpoint(self):
      return (self._host, self._port)
  
    def _GetSshConfigPath(self):
      return self._ssh_config_path
  