openstack-ansible-plugins/connection/ssh.py

# Copyright 2016, Rackspace US, Inc.
#
# 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.
#
# (c) 2016, Kevin Carter <kevin.carter@rackspace.com>

import imp
import os

# NOTICE(cloudnull): The connection plugin imported using the full path to the
#                    file because the ssh connection plugin is not importable.
import ansible.plugins.connection as conn
SSH = imp.load_source(
    'ssh',
    os.path.join(os.path.dirname(conn.__file__), 'ssh.py')
)

class Connection(SSH.Connection):
    """Transport options for LXC containers.

    This transport option makes the assumption that the playbook context has
    vars within it that contain "physical_host" which is the machine running a
    given container and "container_name" which is the actual name of the
    container. These options can be added into the playbook via vars set as
    attributes or though the modification of the a given execution strategy to
    set the attributes accordingly.

    This plugin operates exactly the same way as the standard SSH plugin but
    will pad pathing or add command syntax for lxc containers when a container
    is detected at runtime.
    """

    transport = 'ssh'

    def __init__(self, *args, **kwargs):
        super(Connection, self).__init__(*args, **kwargs)
        self.args = args
        self.kwargs = kwargs
        self.vars = self._play_context._attributes['vars']
        self.chroot_path = self.vars.get('chroot_path')
        self.container_name = self.vars.get('container_name')
        self.physical_host = self.vars.get('physical_host')
        self.physical_hostname = self.vars.get('physical_hostname')
        if self._container_check() or self._chroot_check():
            self.host = self._play_context.remote_addr = self.physical_host

    def exec_command(self, cmd, in_data=None, sudoable=True):
        """run a command on the remote host."""

        if self._container_check():
            lxc_command = 'lxc-attach --name %s' % self.container_name
            cmd = '%s -- %s' % (lxc_command, cmd)

        if self._chroot_check():
            chroot_command = 'chroot %s' % self.chroot_path
            cmd = '%s %s' % (chroot_command, cmd)

        return super(Connection, self).exec_command(cmd, in_data, sudoable)

    def _chroot_check(self):
        if self.chroot_path:
            SSH.display.vvv(u'chroot_path: "%s"' % self.chroot_path)
            if self.physical_hostname:
                SSH.display.vvv(
                    u'physical_hostname: "%s"' % self.physical_hostname
                )
                SSH.display.vvv(u'chroot confirmed')
                return True

        return False

    def _container_check(self):
        if self.container_name:
            SSH.display.vvv(u'container_name: "%s"' % self.container_name)
            if self.physical_hostname:
                SSH.display.vvv(
                    u'physical_hostname: "%s"' % self.physical_hostname
                )
                if self.container_name != self.physical_hostname:
                    SSH.display.vvv(u'Container confirmed')
                    return True

        return False

    def _container_path_pad(self, path, fake_path=False):
        args = (
            'ssh',
            self.host,
            u"lxc-info --name %s --pid | awk '/PID:/ {print $2}'"
            % self.container_name
        )
        returncode, stdout, _ = self._run(
            self._build_command(*args),
            in_data=None,
            sudoable=False
        )
        if returncode == 0:
            pad = os.path.join(
                '/proc/%s/root' % stdout.strip(),
                path.lstrip(os.sep)
            )
            SSH.display.vvv(
                u'The path has been padded with the following to support a'
                u' container rootfs: [ %s ]' % pad
            )
            return pad
        else:
            raise SSH.AnsibleError(
                u'No valid container info was found for container "%s" Please'
                u' check the state of the container.' % self.container_name
            )

    def fetch_file(self, in_path, out_path):
        """fetch a file from remote to local."""
        if self._container_check():
            in_path = self._container_path_pad(path=in_path)

        return super(Connection, self).fetch_file(in_path, out_path)

    def put_file(self, in_path, out_path):
        """transfer a file from local to remote."""
        if self._container_check():
            out_path = self._container_path_pad(path=out_path)

        return super(Connection, self).put_file(in_path, out_path)

    def close(self):
        # If we have a persistent ssh connection (ControlPersist), we can ask it
        # to stop listening. Otherwise, there's nothing to do here.
        if self._connected and self._persistent:
            cmd = self._build_command('ssh', '-O', 'stop', self.host)
            cmd = map(SSH.to_bytes, cmd)
            p = SSH.subprocess.Popen(cmd, stdin=SSH.subprocess.PIPE, stdout=SSH.subprocess.PIPE, stderr=SSH.subprocess.PIPE)
            p.communicate()