text: # Based on local.py (c) 2012, Michael DeHaan <michael.dehaan@gmail.com>
  # Based on chroot.py (c) 2013, Maykel Moya <mmoya@speedyrails.com>
  # (c) 2013, Michael Scherer <misc@zarb.org>
  # (c) 2015, Toshio Kuratomi <tkuratomi@ansible.com>
  #
  # This file is part of Ansible
  #
  # Ansible is free software: you can redistribute it and/or modify
  # it under the terms of the GNU General Public License as published by
  # the Free Software Foundation, either version 3 of the License, or
  # (at your option) any later version.
  #
  # Ansible is distributed in the hope that it will be useful,
  # but WITHOUT ANY WARRANTY; without even the implied warranty of
  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  # GNU General Public License for more details.
  #
  # You should have received a copy of the GNU General Public License
  # along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
  from __future__ import (absolute_import, division, print_function)
  __metaclass__ = type
  
  import distutils.spawn
  import os
  import os.path
  import pipes
  import subprocess
  import traceback
  
  from ansible import constants as C
  from ansible.errors import AnsibleError
  from ansible.plugins.connection import ConnectionBase
  from ansible.utils.unicode import to_bytes
  
  try:
      from __main__ import display
  except ImportError:
      from ansible.utils.display import Display
      display = Display()
  
  BUFSIZE = 65536
  
  
  class Connection(ConnectionBase):
      ''' Local lxc based connections '''
  
      transport = 'libvirt_lxc'
      has_pipelining = True
      # su currently has an undiagnosed issue with calculating the file
      # checksums (so copy, for instance, doesn't work right)
      # Have to look into that before re-enabling this
      become_methods = frozenset(C.BECOME_METHODS).difference(('su',))
  
      def __init__(self, play_context, new_stdin, *args, **kwargs):
          super(Connection, self).__init__(play_context, new_stdin, *args, **kwargs)
          self.lxc = self._play_context.remote_addr
  
          self.virsh = self._search_executable('virsh')
  
          self._check_domain(self.lxc)
  
      def _search_executable(self, executable):
          cmd = distutils.spawn.find_executable(executable)
          if not cmd:
              raise AnsibleError("%s command not found in PATH") % executable
          return cmd
  
      def _check_domain(self, domain):
          p = subprocess.Popen([self.virsh, '-q', '-c', 'lxc:///', 'dominfo', to_bytes(domain)],
                               stdout=subprocess.PIPE, stderr=subprocess.PIPE)
          p.communicate()
          if p.returncode:
              raise AnsibleError("%s is not a lxc defined in libvirt" % domain)
  
      def _connect(self):
          ''' connect to the lxc; nothing to do here '''
          super(Connection, self)._connect()
          if not self._connected:
              display.vvv("THIS IS A LOCAL LXC DIR", host=self.lxc)
              self._connected = True
  
      def _buffered_exec_command(self, cmd, stdin=subprocess.PIPE):
          ''' run a command on the chroot.  This is only needed for implementing
          put_file() get_file() so that we don't have to read the whole file
          into memory.
  
          compared to exec_command() it looses some niceties like being able to
          return the process's exit code immediately.
          '''
          executable = C.DEFAULT_EXECUTABLE.split()[0] if C.DEFAULT_EXECUTABLE else '/bin/sh'
          local_cmd = [self.virsh, '-q', '-c', 'lxc:///', 'lxc-enter-namespace', self.lxc, '--', executable , '-c', cmd]
  
          display.vvv("EXEC %s" % (local_cmd,), host=self.lxc)
          local_cmd = map(to_bytes, local_cmd)
          p = subprocess.Popen(local_cmd, shell=False, stdin=stdin,
                  stdout=subprocess.PIPE, stderr=subprocess.PIPE)
  
          return p
  
      def exec_command(self, cmd, in_data=None, sudoable=False):
          ''' run a command on the chroot '''
          super(Connection, self).exec_command(cmd, in_data=in_data, sudoable=sudoable)
  
          p = self._buffered_exec_command(cmd)
  
          stdout, stderr = p.communicate(in_data)
          return (p.returncode, stdout, stderr)
  
      def _prefix_login_path(self, remote_path):
          ''' Make sure that we put files into a standard path
  
              If a path is relative, then we need to choose where to put it.
              ssh chooses $HOME but we aren't guaranteed that a home dir will
              exist in any given chroot.  So for now we're choosing "/" instead.
              This also happens to be the former default.
  
              Can revisit using $HOME instead if it's a problem
          '''
          if not remote_path.startswith(os.path.sep):
              remote_path = os.path.join(os.path.sep, remote_path)
          return os.path.normpath(remote_path)
  
      def put_file(self, in_path, out_path):
          ''' transfer a file from local to lxc '''
          super(Connection, self).put_file(in_path, out_path)
          display.vvv("PUT %s TO %s" % (in_path, out_path), host=self.lxc)
  
          out_path = pipes.quote(self._prefix_login_path(out_path))
          try:
              with open(in_path, 'rb') as in_file:
                  try:
                      p = self._buffered_exec_command('dd of=%s bs=%s' % (out_path, BUFSIZE), stdin=in_file)
                  except OSError:
                      raise AnsibleError("chroot connection requires dd command in the chroot")
                  try:
                      stdout, stderr = p.communicate()
                  except:
                      traceback.print_exc()
                      raise AnsibleError("failed to transfer file %s to %s" % (in_path, out_path))
                  if p.returncode != 0:
                      raise AnsibleError("failed to transfer file %s to %s:\n%s\n%s" % (in_path, out_path, stdout, stderr))
          except IOError:
              raise AnsibleError("file or module does not exist at: %s" % in_path)
  
      def fetch_file(self, in_path, out_path):
          ''' fetch a file from lxc to local '''
          super(Connection, self).fetch_file(in_path, out_path)
          display.vvv("FETCH %s TO %s" % (in_path, out_path), host=self.lxc)
  
          in_path = pipes.quote(self._prefix_login_path(in_path))
          try:
              p = self._buffered_exec_command('dd if=%s bs=%s' % (in_path, BUFSIZE))
          except OSError:
              raise AnsibleError("chroot connection requires dd command in the chroot")
  
          with open(out_path, 'wb+') as out_file:
              try:
                  chunk = p.stdout.read(BUFSIZE)
                  while chunk:
                      out_file.write(chunk)
                      chunk = p.stdout.read(BUFSIZE)
              except:
                  traceback.print_exc()
                  raise AnsibleError("failed to transfer file %s to %s" % (in_path, out_path))
              stdout, stderr = p.communicate()
              if p.returncode != 0:
                  raise AnsibleError("failed to transfer file %s to %s:\n%s\n%s" % (in_path, out_path, stdout, stderr))
  
      def close(self):
          ''' terminate the connection; nothing to do here '''
          super(Connection, self).close()
          self._connected = False
  