# Copyright 2017, David Wilson # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions are met: # # 1. Redistributions of source code must retain the above copyright notice, # this list of conditions and the following disclaimer. # # 2. Redistributions in binary form must reproduce the above copyright notice, # this list of conditions and the following disclaimer in the documentation # and/or other materials provided with the distribution. # # 3. Neither the name of the copyright holder nor the names of its contributors # may be used to endorse or promote products derived from this software without # specific prior written permission. # # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE # ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE # LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR # CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF # SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS # INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN # CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) # ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE # POSSIBILITY OF SUCH DAMAGE. from __future__ import absolute_import from __future__ import unicode_literals import logging import os import stat import time import jinja2.runtime import ansible.constants as C import ansible.errors import ansible.plugins.connection import ansible.utils.shlex import mitogen.unix import mitogen.utils import ansible_mitogen.parsing import ansible_mitogen.process import ansible_mitogen.services import ansible_mitogen.target LOG = logging.getLogger(__name__) def optional_secret(value): """ Wrap `value` in :class:`mitogen.core.Secret` if it is not :data:`None`, otherwise return :data:`None`. """ if value is not None: return mitogen.core.Secret(value) def parse_python_path(s): """ Given the string set for ansible_python_interpeter, parse it using shell syntax and return an appropriate argument vector. """ if s: return ansible.utils.shlex.shlex_split(s) def _connect_local(spec): """ Return ContextService arguments for a local connection. """ return { 'method': 'local', 'kwargs': { 'python_path': spec['python_path'], } } def _connect_ssh(spec): """ Return ContextService arguments for an SSH connection. """ if C.HOST_KEY_CHECKING: check_host_keys = 'enforce' else: check_host_keys = 'ignore' return { 'method': 'ssh', 'kwargs': { 'check_host_keys': check_host_keys, 'hostname': spec['remote_addr'], 'username': spec['remote_user'], 'password': optional_secret(spec['password']), 'port': spec['port'], 'python_path': spec['python_path'], 'identity_file': spec['private_key_file'], 'identities_only': False, 'ssh_path': spec['ssh_executable'], 'connect_timeout': spec['ansible_ssh_timeout'], 'ssh_args': spec['ssh_args'], 'ssh_debug_level': spec['mitogen_ssh_debug_level'], } } def _connect_docker(spec): """ Return ContextService arguments for a Docker connection. """ return { 'method': 'docker', 'kwargs': { 'username': spec['remote_user'], 'container': spec['remote_addr'], 'python_path': spec['python_path'], 'connect_timeout': spec['ansible_ssh_timeout'] or spec['timeout'], } } def _connect_jail(spec): """ Return ContextService arguments for a FreeBSD jail connection. """ return { 'method': 'jail', 'kwargs': { 'username': spec['remote_user'], 'container': spec['remote_addr'], 'python_path': spec['python_path'], 'connect_timeout': spec['ansible_ssh_timeout'] or spec['timeout'], } } def _connect_lxc(spec): """ Return ContextService arguments for an LXC Classic container connection. """ return { 'method': 'lxc', 'kwargs': { 'container': spec['remote_addr'], 'python_path': spec['python_path'], 'connect_timeout': spec['ansible_ssh_timeout'] or spec['timeout'], } } def _connect_lxd(spec): """ Return ContextService arguments for an LXD container connection. """ return { 'method': 'lxd', 'kwargs': { 'container': spec['remote_addr'], 'python_path': spec['python_path'], 'connect_timeout': spec['ansible_ssh_timeout'] or spec['timeout'], } } def _connect_machinectl(spec): """ Return ContextService arguments for a machinectl connection. """ return _connect_setns(dict(spec, mitogen_kind='machinectl')) def _connect_setns(spec): """ Return ContextService arguments for a mitogen_setns connection. """ return { 'method': 'setns', 'kwargs': { 'container': spec['remote_addr'], 'username': spec['remote_user'], 'python_path': spec['python_path'], 'kind': spec['mitogen_kind'], 'docker_path': spec['mitogen_docker_path'], 'lxc_info_path': spec['mitogen_lxc_info_path'], 'machinectl_path': spec['mitogen_machinectl_path'], } } def _connect_su(spec): """ Return ContextService arguments for su as a become method. """ return { 'method': 'su', 'enable_lru': True, 'kwargs': { 'username': spec['become_user'], 'password': optional_secret(spec['become_pass']), 'python_path': spec['python_path'], 'su_path': spec['become_exe'], 'connect_timeout': spec['timeout'], } } def _connect_sudo(spec): """ Return ContextService arguments for sudo as a become method. """ return { 'method': 'sudo', 'enable_lru': True, 'kwargs': { 'username': spec['become_user'], 'password': optional_secret(spec['become_pass']), 'python_path': spec['python_path'], 'sudo_path': spec['become_exe'], 'connect_timeout': spec['timeout'], 'sudo_args': spec['sudo_args'], } } def _connect_doas(spec): """ Return ContextService arguments for doas as a become method. """ return { 'method': 'doas', 'enable_lru': True, 'kwargs': { 'username': spec['become_user'], 'password': optional_secret(spec['become_pass']), 'python_path': spec['python_path'], 'doas_path': spec['become_exe'], 'connect_timeout': spec['timeout'], } } def _connect_mitogen_su(spec): """ Return ContextService arguments for su as a first class connection. """ return { 'method': 'su', 'kwargs': { 'username': spec['remote_user'], 'password': optional_secret(spec['password']), 'python_path': spec['python_path'], 'su_path': spec['become_exe'], 'connect_timeout': spec['timeout'], } } def _connect_mitogen_sudo(spec): """ Return ContextService arguments for sudo as a first class connection. """ return { 'method': 'sudo', 'kwargs': { 'username': spec['remote_user'], 'password': optional_secret(spec['password']), 'python_path': spec['python_path'], 'sudo_path': spec['become_exe'], 'connect_timeout': spec['timeout'], 'sudo_args': spec['sudo_args'], } } def _connect_mitogen_doas(spec): """ Return ContextService arguments for doas as a first class connection. """ return { 'method': 'doas', 'kwargs': { 'username': spec['remote_user'], 'password': optional_secret(spec['password']), 'python_path': spec['python_path'], 'doas_path': spec['become_exe'], 'connect_timeout': spec['timeout'], } } #: Mapping of connection method names to functions invoked as `func(spec)` #: generating ContextService keyword arguments matching a connection #: specification. CONNECTION_METHOD = { 'docker': _connect_docker, 'jail': _connect_jail, 'local': _connect_local, 'lxc': _connect_lxc, 'lxd': _connect_lxd, 'machinectl': _connect_machinectl, 'setns': _connect_setns, 'ssh': _connect_ssh, 'su': _connect_su, 'sudo': _connect_sudo, 'doas': _connect_doas, 'mitogen_su': _connect_mitogen_su, 'mitogen_sudo': _connect_mitogen_sudo, 'mitogen_doas': _connect_mitogen_doas, } def config_from_play_context(transport, inventory_name, connection): """ Return a dict representing all important connection configuration, allowing the same functions to work regardless of whether configuration came from play_context (direct connection) or host vars (mitogen_via=). """ return { 'transport': transport, 'inventory_name': inventory_name, 'remote_addr': connection._play_context.remote_addr, 'remote_user': connection._play_context.remote_user, 'become': connection._play_context.become, 'become_method': connection._play_context.become_method, 'become_user': connection._play_context.become_user, 'become_pass': connection._play_context.become_pass, 'password': connection._play_context.password, 'port': connection._play_context.port, 'python_path': parse_python_path( connection.get_task_var('ansible_python_interpreter', default='/usr/bin/python') ), 'private_key_file': connection._play_context.private_key_file, 'ssh_executable': connection._play_context.ssh_executable, 'timeout': connection._play_context.timeout, 'ansible_ssh_timeout': connection.get_task_var('ansible_ssh_timeout', default=C.DEFAULT_TIMEOUT), 'ssh_args': [ mitogen.core.to_text(term) for s in ( getattr(connection._play_context, 'ssh_args', ''), getattr(connection._play_context, 'ssh_common_args', ''), getattr(connection._play_context, 'ssh_extra_args', '') ) for term in ansible.utils.shlex.shlex_split(s or '') ], 'become_exe': connection._play_context.become_exe, 'sudo_args': [ mitogen.core.to_text(term) for s in ( connection._play_context.sudo_flags, connection._play_context.become_flags ) for term in ansible.utils.shlex.shlex_split(s or '') ], 'mitogen_via': connection.get_task_var('mitogen_via'), 'mitogen_kind': connection.get_task_var('mitogen_kind'), 'mitogen_docker_path': connection.get_task_var('mitogen_docker_path'), 'mitogen_lxc_info_path': connection.get_task_var('mitogen_lxc_info_path'), 'mitogen_machinectl_path': connection.get_task_var('mitogen_machinectl_path'), 'mitogen_ssh_debug_level': connection.get_task_var('mitogen_ssh_debug_level'), } def config_from_hostvars(transport, inventory_name, connection, hostvars, become_user): """ Override config_from_play_context() to take equivalent information from host vars. """ config = config_from_play_context(transport, inventory_name, connection) hostvars = dict(hostvars) return dict(config, **{ 'remote_addr': hostvars.get('ansible_host', inventory_name), 'become': bool(become_user), 'become_user': become_user, 'become_pass': None, 'remote_user': hostvars.get('ansible_user'), # TODO 'password': (hostvars.get('ansible_ssh_pass') or hostvars.get('ansible_password')), 'port': hostvars.get('ansible_port'), 'python_path': parse_python_path(hostvars.get('ansible_python_interpreter')), 'private_key_file': (hostvars.get('ansible_ssh_private_key_file') or hostvars.get('ansible_private_key_file')), 'mitogen_via': hostvars.get('mitogen_via'), 'mitogen_kind': hostvars.get('mitogen_kind'), 'mitogen_docker_path': hostvars.get('mitogen_docker_path'), 'mitogen_lxc_info_path': hostvars.get('mitogen_lxc_info_path'), 'mitogen_machinectl_path': hostvars.get('mitogen_machinctl_path'), }) class CallChain(mitogen.parent.CallChain): call_aborted_msg = ( 'Mitogen was disconnected from the remote environment while a call ' 'was in-progress. If you feel this is in error, please file a bug. ' 'Original error was: %s' ) def _rethrow(self, recv): try: return recv.get().unpickle() except mitogen.core.ChannelError as e: raise ansible.errors.AnsibleConnectionFailure( self.call_aborted_msg % (e,) ) def call(self, func, *args, **kwargs): """ Like :meth:`mitogen.parent.CallChain.call`, but log timings. """ t0 = time.time() try: recv = self.call_async(func, *args, **kwargs) return self._rethrow(recv) finally: LOG.debug('Call took %d ms: %r', 1000 * (time.time() - t0), mitogen.parent.CallSpec(func, args, kwargs)) class Connection(ansible.plugins.connection.ConnectionBase): #: mitogen.master.Broker for this worker. broker = None #: mitogen.master.Router for this worker. router = None #: mitogen.parent.Context representing the parent Context, which is #: presently always the connection multiplexer process. parent = None #: mitogen.parent.Context for the target account on the target, possibly #: reached via become. context = None #: Context for the login account on the target. This is always the login #: account, even when become=True. login_context = None #: Only sudo, su, and doas are supported for now. become_methods = ['sudo', 'su', 'doas'] #: Dict containing init_child() return vaue as recorded at startup by #: ContextService. Contains: #: #: fork_context: Context connected to the fork parent : process in the #: target account. #: home_dir: Target context's home directory. #: temp_dir: A writeable temporary directory managed by the #: target, automatically destroyed at shutdown. init_child_result = None #: A private temporary directory destroyed during :meth:`close`, or #: automatically during shutdown if :meth:`close` failed or was never #: called. temp_dir = None #: A :class:`mitogen.parent.CallChain` to use for calls made to the target #: account, to ensure subsequent calls fail if pipelined directory creation #: or file transfer fails. This eliminates roundtrips when a call is likely #: to succeed, and ensures subsequent actions will fail with the original #: exception if the pipelined call failed. chain = None # # Note: any of the attributes below may be :data:`None` if the connection # plugin was constructed directly by a non-cooperative action, such as in # the case of the synchronize module. # #: Set to the host name as it appears in inventory by on_action_run(). inventory_hostname = None #: Set to task_vars by on_action_run(). _task_vars = None #: Set to 'hostvars' by on_action_run() host_vars = None #: Set by on_action_run() delegate_to_hostname = None #: Set to '_loader.get_basedir()' by on_action_run(). Used by mitogen_local #: to change the working directory to that of the current playbook, #: matching vanilla Ansible behaviour. loader_basedir = None def __init__(self, play_context, new_stdin, **kwargs): assert ansible_mitogen.process.MuxProcess.unix_listener_path, ( 'Mitogen connection types may only be instantiated ' 'while the "mitogen" strategy is active.' ) super(Connection, self).__init__(play_context, new_stdin) def __del__(self): """ Ansible cannot be trusted to always call close() e.g. the synchronize action constructs a local connection like this. So provide a destructor in the hopes of catching these cases. """ # https://github.com/dw/mitogen/issues/140 self.close() def on_action_run(self, task_vars, delegate_to_hostname, loader_basedir): """ Invoked by ActionModuleMixin to indicate a new task is about to start executing. We use the opportunity to grab relevant bits from the task-specific data. :param dict task_vars: Task variable dictionary. :param str delegate_to_hostname: :data:`None`, or the template-expanded inventory hostname this task is being delegated to. A similar variable exists on PlayContext when ``delegate_to:`` is active, however it is unexpanded. :param str loader_basedir: Loader base directory; see :attr:`loader_basedir`. """ self.inventory_hostname = task_vars['inventory_hostname'] self._task_vars = task_vars self.host_vars = task_vars['hostvars'] self.delegate_to_hostname = delegate_to_hostname self.loader_basedir = loader_basedir self.close(new_task=True) def get_task_var(self, key, default=None): if self._task_vars and key in self._task_vars: return self._task_vars[key] return default @property def homedir(self): self._connect() return self.init_child_result['home_dir'] @property def connected(self): return self.context is not None def _config_from_via(self, via_spec): """ Produce a dict connection specifiction given a string `via_spec`, of the form `[become_user@]inventory_hostname`. """ become_user, _, inventory_name = via_spec.rpartition('@') via_vars = self.host_vars[inventory_name] if isinstance(via_vars, jinja2.runtime.Undefined): raise ansible.errors.AnsibleConnectionFailure( self.unknown_via_msg % ( via_spec, inventory_name, ) ) return config_from_hostvars( transport=via_vars.get('ansible_connection', 'ssh'), inventory_name=inventory_name, connection=self, hostvars=via_vars, become_user=become_user or None, ) unknown_via_msg = 'mitogen_via=%s of %s specifies an unknown hostname' via_cycle_msg = 'mitogen_via=%s of %s creates a cycle (%s)' def _stack_from_config(self, config, stack=(), seen_names=()): if config['inventory_name'] in seen_names: raise ansible.errors.AnsibleConnectionFailure( self.via_cycle_msg % ( config['mitogen_via'], config['inventory_name'], ' -> '.join(reversed( seen_names + (config['inventory_name'],) )), ) ) if config['mitogen_via']: stack, seen_names = self._stack_from_config( self._config_from_via(config['mitogen_via']), stack=stack, seen_names=seen_names + (config['inventory_name'],) ) stack += (CONNECTION_METHOD[config['transport']](config),) if config['become']: stack += (CONNECTION_METHOD[config['become_method']](config),) return stack, seen_names def _connect_broker(self): """ Establish a reference to the Broker, Router and parent context used for connections. """ if not self.broker: self.broker = mitogen.master.Broker() self.router, self.parent = mitogen.unix.connect( path=ansible_mitogen.process.MuxProcess.unix_listener_path, broker=self.broker, ) def _config_from_direct_connection(self): """ """ return config_from_play_context( transport=self.transport, inventory_name=self.inventory_hostname, connection=self ) def _config_from_delegate_to(self): return config_from_hostvars( transport=self._play_context.connection, inventory_name=self.delegate_to_hostname, connection=self, hostvars=self.host_vars[self.delegate_to_hostname], become_user=(self._play_context.become_user if self._play_context.become else None), ) def _build_stack(self): """ Construct a list of dictionaries representing the connection configuration between the controller and the target. This is additionally used by the integration tests "mitogen_get_stack" action to fetch the would-be connection configuration. """ if self.delegate_to_hostname is not None: target_config = self._config_from_delegate_to() else: target_config = self._config_from_direct_connection() stack, _ = self._stack_from_config(target_config) return stack def _connect_stack(self, stack): """ Pass `stack` to ContextService, requesting a copy of the context object representing the target. If no connection exists yet, ContextService will establish it before returning it or throwing an error. """ dct = self.parent.call_service( service_name='ansible_mitogen.services.ContextService', method_name='get', stack=mitogen.utils.cast(list(stack)), ) if dct['msg']: if dct['method_name'] in self.become_methods: raise ansible.errors.AnsibleModuleError(dct['msg']) raise ansible.errors.AnsibleConnectionFailure(dct['msg']) self.context = dct['context'] self.chain = CallChain(self.context, pipelined=True) if self._play_context.become: self.login_context = dct['via'] else: self.login_context = self.context self.init_child_result = dct['init_child_result'] def _init_temp_dir(self): """ """ self.temp_dir = os.path.join( self.init_child_result['temp_dir'], 'worker-%d-%x' % (os.getpid(), id(self)) ) self.get_chain().call_no_reply(os.mkdir, self.temp_dir) def _connect(self): """ Establish a connection to the master process's UNIX listener socket, constructing a mitogen.master.Router to communicate with the master, and a mitogen.parent.Context to represent it. Depending on the original transport we should emulate, trigger one of the _connect_*() service calls defined above to cause the master process to establish the real connection on our behalf, or return a reference to the existing one. """ if self.connected: return self._connect_broker() stack = self._build_stack() self._connect_stack(stack) self._init_temp_dir() def close(self, new_task=False): """ Arrange for the mitogen.master.Router running in the worker to gracefully shut down, and wait for shutdown to complete. Safe to call multiple times. """ if self.context: self.chain.reset() # No pipelining to ensure exception is logged on failure. self.context.call_no_reply(ansible_mitogen.target.prune_tree, self.temp_dir) self.parent.call_service( service_name='ansible_mitogen.services.ContextService', method_name='put', context=self.context ) self.temp_dir = None self.context = None self.login_context = None self.init_child_result = None self.chain = None if self.broker and not new_task: self.broker.shutdown() self.broker.join() self.broker = None self.router = None def get_chain(self, use_login=False, use_fork=False): """ Return the :class:`mitogen.parent.CallChain` to use for executing function calls. :param bool use_login: If :data:`True`, always return the chain for the login account rather than any active become user. :param bool use_fork: If :data:`True`, return the chain for the fork parent. :returns mitogen.parent.CallChain: """ self._connect() if use_login: return self.login_context.default_call_chain if use_fork: return self.init_child_result['fork_context'].default_call_chain return self.chain def create_fork_child(self): """ Fork a new child off the target context. The actual fork occurs from the 'virginal fork parent', which does not any Ansible modules prior to fork, to avoid conflicts resulting from custom module_utils paths. :returns: mitogen.core.Context of the new child. """ return self.get_chain(use_fork=True).call( ansible_mitogen.target.create_fork_child ) def get_default_cwd(self): """ Overridden by connections/mitogen_local.py to emulate behaviour of CWD being fixed to that of ActionBase._loader.get_basedir(). """ return None def get_default_env(self): """ Overridden by connections/mitogen_local.py to emulate behaviour of WorkProcess environment inherited from WorkerProcess. """ return None def exec_command(self, cmd, in_data='', sudoable=True, mitogen_chdir=None): """ Implement exec_command() by calling the corresponding ansible_mitogen.target function in the target. :param str cmd: Shell command to execute. :param bytes in_data: Data to supply on ``stdin`` of the process. :returns: (return code, stdout bytes, stderr bytes) """ emulate_tty = (not in_data and sudoable) rc, stdout, stderr = self.call( ansible_mitogen.target.exec_command, cmd=mitogen.utils.cast(cmd), in_data=mitogen.utils.cast(in_data), chdir=mitogen_chdir or self.get_default_cwd(), emulate_tty=emulate_tty, ) stderr += 'Shared connection to %s closed.%s' % ( self._play_context.remote_addr, ('\r\n' if emulate_tty else '\n'), ) return rc, stdout, stderr def fetch_file(self, in_path, out_path): """ Implement fetch_file() by calling the corresponding ansible_mitogen.target function in the target. :param str in_path: Remote filesystem path to read. :param str out_path: Local filesystem path to write. """ output = self.get_chain().call( ansible_mitogen.target.read_path, mitogen.utils.cast(in_path), ) ansible_mitogen.target.write_path(out_path, output) def put_data(self, out_path, data, mode=None, utimes=None): """ Implement put_file() by caling the corresponding ansible_mitogen.target function in the target, transferring small files inline. This is pipelined and will return immediately; failed transfers are reported as exceptions in subsequent functon calls. :param str out_path: Remote filesystem path to write. :param byte data: File contents to put. """ self.get_chain().call_no_reply( ansible_mitogen.target.write_path, mitogen.utils.cast(out_path), mitogen.core.Blob(data), mode=mode, utimes=utimes, ) #: Maximum size of a small file before switching to streaming #: transfer. This should really be the same as #: mitogen.services.FileService.IO_SIZE, however the message format has #: slightly more overhead, so just randomly subtract 4KiB. SMALL_FILE_LIMIT = mitogen.core.CHUNK_SIZE - 4096 def put_file(self, in_path, out_path): """ Implement put_file() by streamily transferring the file via FileService. :param str in_path: Local filesystem path to read. :param str out_path: Remote filesystem path to write. """ st = os.stat(in_path) if not stat.S_ISREG(st.st_mode): raise IOError('%r is not a regular file.' % (in_path,)) # If the file is sufficiently small, just ship it in the argument list # rather than introducing an extra RTT for the child to request it from # FileService. if st.st_size <= self.SMALL_FILE_LIMIT: fp = open(in_path, 'rb') try: s = fp.read(self.SMALL_FILE_LIMIT + 1) finally: fp.close() # Ensure did not grow during read. if len(s) == st.st_size: return self.put_data(out_path, s, mode=st.st_mode, utimes=(st.st_atime, st.st_mtime)) self.parent.call_service( service_name='mitogen.service.FileService', method_name='register', path=mitogen.utils.cast(in_path) ) # A roundtrip is always necessary for the target to request the file # from FileService, however, by pipelining the transfer function, the # subsequent step (probably a module invocation) can get its # dependencies and function call in-flight before the transfer is # complete. This saves at least 1 RTT between the transfer completing # and the start of the follow-up task. self.get_chain().call_no_reply( ansible_mitogen.target.transfer_file, context=self.parent, in_path=in_path, out_path=out_path )