community.docker/plugins/connection/docker_api.py

# Copyright (c) 2019-2020, Felix Fontein <felix@fontein.de>
# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
# SPDX-License-Identifier: GPL-3.0-or-later

from __future__ import annotations

DOCUMENTATION = r"""
author:
  - Felix Fontein (@felixfontein)
name: docker_api
short_description: Run tasks in docker containers
version_added: 1.1.0
description:
  - Run commands or put/fetch files to an existing docker container.
  - Uses the L(requests library,https://pypi.org/project/requests/) to interact directly with the Docker daemon instead of
    using the Docker CLI. Use the P(community.docker.docker#connection) connection plugin if you want to use the Docker CLI.
notes:
  - Does B(not work with TCP TLS sockets)! This is caused by the inability to send C(close_notify) without closing the connection
    with Python's C(SSLSocket)s. See U(https://github.com/ansible-collections/community.docker/issues/605) for more information.
extends_documentation_fragment:
  - community.docker.docker.api_documentation
  - community.docker.docker.var_names
options:
  remote_user:
    type: str
    description:
      - The user to execute as inside the container.
    vars:
      - name: ansible_user
      - name: ansible_docker_user
    ini:
      - section: defaults
        key: remote_user
    env:
      - name: ANSIBLE_REMOTE_USER
    cli:
      - name: user
    keyword:
      - name: remote_user
  remote_addr:
    type: str
    description:
      - The name of the container you want to access.
    default: inventory_hostname
    vars:
      - name: inventory_hostname
      - name: ansible_host
      - name: ansible_docker_host
  container_timeout:
    default: 10
    description:
      - Controls how long we can wait to access reading output from the container once execution started.
    env:
      - name: ANSIBLE_TIMEOUT
      - name: ANSIBLE_DOCKER_TIMEOUT
        version_added: 2.2.0
    ini:
      - key: timeout
        section: defaults
      - key: timeout
        section: docker_connection
        version_added: 2.2.0
    vars:
      - name: ansible_docker_timeout
        version_added: 2.2.0
    cli:
      - name: timeout
    type: integer
  extra_env:
    description:
      - Provide extra environment variables to set when running commands in the Docker container.
      - This option can currently only be provided as Ansible variables due to limitations of ansible-core's configuration
        manager.
    vars:
      - name: ansible_docker_extra_env
    type: dict
    version_added: 3.12.0
  working_dir:
    description:
      - The directory inside the container to run commands in.
      - Requires Docker API version 1.35 or later.
    env:
      - name: ANSIBLE_DOCKER_WORKING_DIR
    ini:
      - key: working_dir
        section: docker_connection
    vars:
      - name: ansible_docker_working_dir
    type: string
    version_added: 3.12.0
  privileged:
    description:
      - Whether commands should be run with extended privileges.
      - B(Note) that this allows command to potentially break out of the container. Use with care!
    env:
      - name: ANSIBLE_DOCKER_PRIVILEGED
    ini:
      - key: privileged
        section: docker_connection
    vars:
      - name: ansible_docker_privileged
    type: boolean
    default: false
    version_added: 3.12.0
"""

import os
import os.path

from ansible.errors import AnsibleFileNotFound, AnsibleConnectionFailure
from ansible.module_utils.common.text.converters import to_bytes, to_native, to_text
from ansible.plugins.connection import ConnectionBase
from ansible.utils.display import Display

from ansible_collections.community.docker.plugins.module_utils.common_api import (
    RequestException,
)
from ansible_collections.community.docker.plugins.module_utils.copy import (
    DockerFileCopyError,
    DockerFileNotFound,
    fetch_file,
    put_file,
)

from ansible_collections.community.docker.plugins.plugin_utils.socket_handler import (
    DockerSocketHandler,
)
from ansible_collections.community.docker.plugins.plugin_utils.common_api import (
    AnsibleDockerClient,
)

from ansible_collections.community.docker.plugins.module_utils._api.errors import APIError, DockerException, NotFound

from ansible_collections.community.docker.plugins.module_utils.version import LooseVersion

MIN_DOCKER_API = None


display = Display()


class Connection(ConnectionBase):
    ''' Local docker based connections '''

    transport = 'community.docker.docker_api'
    has_pipelining = True

    def _call_client(self, callable, not_found_can_be_resource=False):
        try:
            return callable()
        except NotFound as e:
            if not_found_can_be_resource:
                raise AnsibleConnectionFailure('Could not find container "{1}" or resource in it ({0})'.format(e, self.get_option('remote_addr')))
            else:
                raise AnsibleConnectionFailure('Could not find container "{1}" ({0})'.format(e, self.get_option('remote_addr')))
        except APIError as e:
            if e.response is not None and e.response.status_code == 409:
                raise AnsibleConnectionFailure('The container "{1}" has been paused ({0})'.format(e, self.get_option('remote_addr')))
            self.client.fail(
                'An unexpected Docker error occurred for container "{1}": {0}'.format(e, self.get_option('remote_addr'))
            )
        except DockerException as e:
            self.client.fail(
                'An unexpected Docker error occurred for container "{1}": {0}'.format(e, self.get_option('remote_addr'))
            )
        except RequestException as e:
            self.client.fail(
                'An unexpected requests error occurred for container "{1}" when trying to talk to the Docker daemon: {0}'
                .format(e, self.get_option('remote_addr'))
            )

    def __init__(self, play_context, new_stdin, *args, **kwargs):
        super(Connection, self).__init__(play_context, new_stdin, *args, **kwargs)

        self.client = None
        self.ids = dict()

        # Windows uses Powershell modules
        if getattr(self._shell, "_IS_WINDOWS", False):
            self.module_implementation_preferences = ('.ps1', '.exe', '')

        self.actual_user = None

    def _connect(self, port=None):
        """ Connect to the container. Nothing to do """
        super(Connection, self)._connect()
        if not self._connected:
            self.actual_user = self.get_option('remote_user')
            display.vvv(u"ESTABLISH DOCKER CONNECTION FOR USER: {0}".format(
                self.actual_user or u'?'), host=self.get_option('remote_addr')
            )
            if self.client is None:
                self.client = AnsibleDockerClient(self, min_docker_api_version=MIN_DOCKER_API)
            self._connected = True

            if self.actual_user is None and display.verbosity > 2:
                # Since we are not setting the actual_user, look it up so we have it for logging later
                # Only do this if display verbosity is high enough that we'll need the value
                # This saves overhead from calling into docker when we do not need to
                display.vvv(u"Trying to determine actual user")
                result = self._call_client(lambda: self.client.get_json('/containers/{0}/json', self.get_option('remote_addr')))
                if result.get('Config'):
                    self.actual_user = result['Config'].get('User')
                    if self.actual_user is not None:
                        display.vvv(u"Actual user is '{0}'".format(self.actual_user))

    def exec_command(self, cmd, in_data=None, sudoable=False):
        """ Run a command on the docker host """

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

        command = [self._play_context.executable, '-c', to_text(cmd)]

        do_become = self.become and self.become.expect_prompt() and sudoable

        display.vvv(
            u"EXEC {0}{1}{2}".format(
                to_text(command),
                ', with stdin ({0} bytes)'.format(len(in_data)) if in_data is not None else '',
                ', with become prompt' if do_become else '',
            ),
            host=self.get_option('remote_addr')
        )

        need_stdin = True if (in_data is not None) or do_become else False

        data = {
            'Container': self.get_option('remote_addr'),
            'User': self.get_option('remote_user') or '',
            'Privileged': self.get_option('privileged'),
            'Tty': False,
            'AttachStdin': need_stdin,
            'AttachStdout': True,
            'AttachStderr': True,
            'Cmd': command,
        }

        if 'detachKeys' in self.client._general_configs:
            data['detachKeys'] = self.client._general_configs['detachKeys']

        if self.get_option('extra_env'):
            data['Env'] = []
            for k, v in self.get_option('extra_env').items():
                for val, what in ((k, 'Key'), (v, 'Value')):
                    if not isinstance(val, str):
                        raise AnsibleConnectionFailure(
                            'Non-string {0} found for extra_env option. Ambiguous env options must be '
                            'wrapped in quotes to avoid them being interpreted. {1}: {2!r}'
                            .format(what.lower(), what, val)
                        )
                data['Env'].append(u'{0}={1}'.format(to_text(k, errors='surrogate_or_strict'), to_text(v, errors='surrogate_or_strict')))

        if self.get_option('working_dir') is not None:
            data['WorkingDir'] = self.get_option('working_dir')
            if self.client.docker_api_version < LooseVersion('1.35'):
                raise AnsibleConnectionFailure(
                    'Providing the working directory requires Docker API version 1.35 or newer.'
                    ' The Docker daemon the connection is using has API version {0}.'
                    .format(self.client.docker_api_version_str)
                )

        exec_data = self._call_client(lambda: self.client.post_json_to_json('/containers/{0}/exec', self.get_option('remote_addr'), data=data))
        exec_id = exec_data['Id']

        data = {
            'Tty': False,
            'Detach': False
        }
        if need_stdin:
            exec_socket = self._call_client(lambda: self.client.post_json_to_stream_socket('/exec/{0}/start', exec_id, data=data))
            try:
                with DockerSocketHandler(display, exec_socket, container=self.get_option('remote_addr')) as exec_socket_handler:
                    if do_become:
                        become_output = [b'']

                        def append_become_output(stream_id, data):
                            become_output[0] += data

                        exec_socket_handler.set_block_done_callback(append_become_output)

                        while not self.become.check_success(become_output[0]) and not self.become.check_password_prompt(become_output[0]):
                            if not exec_socket_handler.select(self.get_option('container_timeout')):
                                stdout, stderr = exec_socket_handler.consume()
                                raise AnsibleConnectionFailure('timeout waiting for privilege escalation password prompt:\n' + to_native(become_output[0]))

                            if exec_socket_handler.is_eof():
                                raise AnsibleConnectionFailure('privilege output closed while waiting for password prompt:\n' + to_native(become_output[0]))

                        if not self.become.check_success(become_output[0]):
                            become_pass = self.become.get_option('become_pass', playcontext=self._play_context)
                            exec_socket_handler.write(to_bytes(become_pass, errors='surrogate_or_strict') + b'\n')

                    if in_data is not None:
                        exec_socket_handler.write(in_data)

                    stdout, stderr = exec_socket_handler.consume()
            finally:
                exec_socket.close()
        else:
            stdout, stderr = self._call_client(lambda: self.client.post_json_to_stream(
                '/exec/{0}/start', exec_id, stream=False, demux=True, tty=False, data=data))

        result = self._call_client(lambda: self.client.get_json('/exec/{0}/json', exec_id))

        return result.get('ExitCode') or 0, stdout or b'', stderr or b''

    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 are not guaranteed that a home dir will
            exist in any given chroot.  So for now we are choosing "/" instead.
            This also happens to be the former default.

            Can revisit using $HOME instead if it is a problem
        '''
        if getattr(self._shell, "_IS_WINDOWS", False):
            import ntpath
            return ntpath.normpath(remote_path)
        else:
            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 docker container """
        super(Connection, self).put_file(in_path, out_path)
        display.vvv("PUT %s TO %s" % (in_path, out_path), host=self.get_option('remote_addr'))

        out_path = self._prefix_login_path(out_path)

        if self.actual_user not in self.ids:
            dummy, ids, dummy = self.exec_command(b'id -u && id -g')
            try:
                user_id, group_id = ids.splitlines()
                self.ids[self.actual_user] = int(user_id), int(group_id)
                display.vvvv(
                    'PUT: Determined uid={0} and gid={1} for user "{2}"'.format(user_id, group_id, self.actual_user),
                    host=self.get_option('remote_addr')
                )
            except Exception as e:
                raise AnsibleConnectionFailure(
                    'Error while determining user and group ID of current user in container "{1}": {0}\nGot value: {2!r}'
                    .format(e, self.get_option('remote_addr'), ids)
                )

        user_id, group_id = self.ids[self.actual_user]
        try:
            self._call_client(
                lambda: put_file(
                    self.client,
                    container=self.get_option('remote_addr'),
                    in_path=in_path,
                    out_path=out_path,
                    user_id=user_id,
                    group_id=group_id,
                    user_name=self.actual_user,
                    follow_links=True,
                ),
                not_found_can_be_resource=True,
            )
        except DockerFileNotFound as exc:
            raise AnsibleFileNotFound(to_native(exc))
        except DockerFileCopyError as exc:
            raise AnsibleConnectionFailure(to_native(exc))

    def fetch_file(self, in_path, out_path):
        """ Fetch a file from container to local. """
        super(Connection, self).fetch_file(in_path, out_path)
        display.vvv("FETCH %s TO %s" % (in_path, out_path), host=self.get_option('remote_addr'))

        in_path = self._prefix_login_path(in_path)

        try:
            self._call_client(
                lambda: fetch_file(
                    self.client,
                    container=self.get_option('remote_addr'),
                    in_path=in_path,
                    out_path=out_path,
                    follow_links=True,
                    log=lambda msg: display.vvvv(msg, host=self.get_option('remote_addr')),
                ),
                not_found_can_be_resource=True,
            )
        except DockerFileNotFound as exc:
            raise AnsibleFileNotFound(to_native(exc))
        except DockerFileCopyError as exc:
            raise AnsibleConnectionFailure(to_native(exc))

    def close(self):
        """ Terminate the connection. Nothing to do for Docker"""
        super(Connection, self).close()
        self._connected = False

    def reset(self):
        self.ids.clear()