# Copyright 2019, 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 """ Mitogen extends Ansible's target configuration mechanism in several ways that require some care: * Per-task configurables in Ansible like ansible_python_interpreter are connection-layer configurables in Mitogen. They must be extracted during each task execution to form the complete connection-layer configuration. * Mitogen has extra configurables not supported by Ansible at all, such as mitogen_ssh_debug_level. These are extracted the same way as ansible_python_interpreter. * Mitogen allows connections to be delegated to other machines. Ansible has no internal framework for this, and so Mitogen must figure out a delegated connection configuration all on its own. It cannot reuse much of the Ansible machinery for building a connection configuration, as that machinery is deeply spread out and hard-wired to expect Ansible's usual mode of operation. For normal and delegate_to connections, Ansible's PlayContext is reused where possible to maximize compatibility, but for proxy hops, configurations are built up using the HostVars magic class to call VariableManager.get_vars() behind the scenes on our behalf. Where Ansible has multiple sources of a configuration item, for example, ansible_ssh_extra_args, Mitogen must (ideally perfectly) reproduce how Ansible arrives at its value, without using mechanisms that are hard-wired or change across Ansible versions. That is what this file is for. It exports two spec classes, one that takes all information from PlayContext, and another that takes (almost) all information from HostVars. """ import abc import os import ansible.utils.shlex import ansible.constants as C from ansible.executor.interpreter_discovery import discover_interpreter from ansible.module_utils.six import with_metaclass from ansible.utils.unsafe_proxy import AnsibleUnsafeText import mitogen.core def run_interpreter_discovery_if_necessary(s, task_vars, action): """ Triggers ansible python interpreter discovery if requested. Caches this value the same way Ansible does it. """ # special case where we've already called discover_interpreter which then # calls low_level_exec_command which then retriggers spec.python_path() # in connect_ssh(), so we'll return the default '/usr/bin/python' to finish building the stack # TODO: possible issues here? Chicken-and-egg issue, in order to `connect_ssh` we need a python path if action._finding_python_interpreter: return '/usr/bin/python' if s in ['auto', 'auto_legacy', 'auto_silent', 'auto_legacy_silent']: # python is the only supported interpreter_name as of Ansible 2.8.6 interpreter_name = 'python' discovered_interpreter_config = u'discovered_interpreter_%s' % interpreter_name if task_vars.get('ansible_facts') is None: task_vars['ansible_facts'] = {} if discovered_interpreter_config not in task_vars['ansible_facts']: action._finding_python_interpreter = True s = AnsibleUnsafeText(discover_interpreter( action=action, interpreter_name=interpreter_name, discovery_mode=s, task_vars=task_vars)) # cache discovered interpreter task_vars['ansible_facts'][discovered_interpreter_config] = s else: s = task_vars['ansible_facts'][discovered_interpreter_config] action._finding_python_interpreter = False return s def parse_python_path(s, task_vars, action): """ Given the string set for ansible_python_interpeter, parse it using shell syntax and return an appropriate argument vector. If the value detected is one of interpreter discovery then run that first. Caches python interpreter discovery value in `facts_from_task_vars` like how Ansible handles this. """ if s: s = run_interpreter_discovery_if_necessary(s, task_vars, action) return ansible.utils.shlex.shlex_split(s) 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 first_true(it, default=None): """ Return the first truthy element from `it`. """ for elem in it: if elem: return elem return default class Spec(with_metaclass(abc.ABCMeta, object)): """ A source for variables that comprise a connection configuration. """ @abc.abstractmethod def transport(self): """ The name of the Ansible plug-in implementing the connection. """ @abc.abstractmethod def inventory_name(self): """ The name of the target being connected to as it appears in Ansible's inventory. """ @abc.abstractmethod def remote_addr(self): """ The network address of the target, or for container and other special targets, some other unique identifier. """ @abc.abstractmethod def remote_user(self): """ The username of the login account on the target. """ @abc.abstractmethod def password(self): """ The password of the login account on the target. """ @abc.abstractmethod def become(self): """ :data:`True` if privilege escalation should be active. """ @abc.abstractmethod def become_method(self): """ The name of the Ansible become method to use. """ @abc.abstractmethod def become_user(self): """ The username of the target account for become. """ @abc.abstractmethod def become_pass(self): """ The password of the target account for become. """ @abc.abstractmethod def port(self): """ The port of the login service on the target machine. """ @abc.abstractmethod def python_path(self): """ Path to the Python interpreter on the target machine. """ @abc.abstractmethod def private_key_file(self): """ Path to the SSH private key file to use to login. """ @abc.abstractmethod def ssh_executable(self): """ Path to the SSH executable. """ @abc.abstractmethod def timeout(self): """ The generic timeout for all connections. """ @abc.abstractmethod def ansible_ssh_timeout(self): """ The SSH-specific timeout for a connection. """ @abc.abstractmethod def ssh_args(self): """ The list of additional arguments that should be included in an SSH invocation. """ @abc.abstractmethod def become_exe(self): """ The path to the executable implementing the become method on the remote machine. """ @abc.abstractmethod def sudo_args(self): """ The list of additional arguments that should be included in a become invocation. """ # TODO: split out into sudo_args/become_args. @abc.abstractmethod def mitogen_via(self): """ The value of the mitogen_via= variable for this connection. Indicates the connection should be established via an intermediary. """ @abc.abstractmethod def mitogen_kind(self): """ The type of container to use with the "setns" transport. """ @abc.abstractmethod def mitogen_mask_remote_name(self): """ Specifies whether to set a fixed "remote_name" field. The remote_name is the suffix of `argv[0]` for remote interpreters. By default it includes identifying information from the local process, which may be undesirable in some circumstances. """ @abc.abstractmethod def mitogen_buildah_path(self): """ The path to the "buildah" program for the 'buildah' transport. """ @abc.abstractmethod def mitogen_docker_path(self): """ The path to the "docker" program for the 'docker' transport. """ @abc.abstractmethod def mitogen_kubectl_path(self): """ The path to the "kubectl" program for the 'docker' transport. """ @abc.abstractmethod def mitogen_lxc_path(self): """ The path to the "lxc" program for the 'lxd' transport. """ @abc.abstractmethod def mitogen_lxc_attach_path(self): """ The path to the "lxc-attach" program for the 'lxc' transport. """ @abc.abstractmethod def mitogen_lxc_info_path(self): """ The path to the "lxc-info" program for the 'lxc' transport. """ @abc.abstractmethod def mitogen_machinectl_path(self): """ The path to the "machinectl" program for the 'setns' transport. """ @abc.abstractmethod def mitogen_ssh_keepalive_interval(self): """ The SSH ServerAliveInterval. """ @abc.abstractmethod def mitogen_ssh_keepalive_count(self): """ The SSH ServerAliveCount. """ @abc.abstractmethod def mitogen_ssh_debug_level(self): """ The SSH debug level. """ @abc.abstractmethod def mitogen_ssh_compression(self): """ Whether SSH compression is enabled. """ @abc.abstractmethod def extra_args(self): """ Connection-specific arguments. """ @abc.abstractmethod def ansible_doas_exe(self): """ Value of "ansible_doas_exe" variable. """ class PlayContextSpec(Spec): """ PlayContextSpec takes almost all its information as-is from Ansible's PlayContext. It is used for normal connections and delegate_to connections, and should always be accurate. """ def __init__(self, connection, play_context, transport, inventory_name, action): self._connection = connection self._play_context = play_context self._transport = transport self._inventory_name = inventory_name self._task_vars = self._connection._get_task_vars() # used to run interpreter discovery self._action = action def transport(self): return self._transport def inventory_name(self): return self._inventory_name def remote_addr(self): return self._play_context.remote_addr def remote_user(self): return self._play_context.remote_user def become(self): return self._play_context.become def become_method(self): return self._play_context.become_method def become_user(self): return self._play_context.become_user def become_pass(self): return optional_secret(self._play_context.become_pass) def password(self): return optional_secret(self._play_context.password) def port(self): return self._play_context.port def python_path(self): s = self._connection.get_task_var('ansible_python_interpreter') # #511, #536: executor/module_common.py::_get_shebang() hard-wires # "/usr/bin/python" as the default interpreter path if no other # interpreter is specified. return parse_python_path( s or '/usr/bin/python', task_vars=self._task_vars, action=self._action) def private_key_file(self): return self._play_context.private_key_file def ssh_executable(self): return self._play_context.ssh_executable def timeout(self): return self._play_context.timeout def ansible_ssh_timeout(self): return ( self._connection.get_task_var('ansible_timeout') or self._connection.get_task_var('ansible_ssh_timeout') or self.timeout() ) def ssh_args(self): return [ mitogen.core.to_text(term) for s in ( getattr(self._play_context, 'ssh_args', ''), getattr(self._play_context, 'ssh_common_args', ''), getattr(self._play_context, 'ssh_extra_args', '') ) for term in ansible.utils.shlex.shlex_split(s or '') ] def become_exe(self): # In Ansible 2.8, PlayContext.become_exe always has a default value due # to the new options mechanism. Previously it was only set if a value # ("somewhere") had been specified for the task. # For consistency in the tests, here we make older Ansibles behave like # newer Ansibles. exe = self._play_context.become_exe if exe is None and self._play_context.become_method == 'sudo': exe = 'sudo' return exe def sudo_args(self): return [ mitogen.core.to_text(term) for term in ansible.utils.shlex.shlex_split( first_true(( self._play_context.become_flags, # Ansible <=2.7. getattr(self._play_context, 'sudo_flags', ''), # Ansible <=2.3. getattr(C, 'DEFAULT_BECOME_FLAGS', ''), getattr(C, 'DEFAULT_SUDO_FLAGS', '') ), default='') ) ] def mitogen_via(self): return self._connection.get_task_var('mitogen_via') def mitogen_kind(self): return self._connection.get_task_var('mitogen_kind') def mitogen_mask_remote_name(self): return self._connection.get_task_var('mitogen_mask_remote_name') def mitogen_buildah_path(self): return self._connection.get_task_var('mitogen_buildah_path') def mitogen_docker_path(self): return self._connection.get_task_var('mitogen_docker_path') def mitogen_kubectl_path(self): return self._connection.get_task_var('mitogen_kubectl_path') def mitogen_lxc_path(self): return self._connection.get_task_var('mitogen_lxc_path') def mitogen_lxc_attach_path(self): return self._connection.get_task_var('mitogen_lxc_attach_path') def mitogen_lxc_info_path(self): return self._connection.get_task_var('mitogen_lxc_info_path') def mitogen_ssh_keepalive_interval(self): return self._connection.get_task_var('mitogen_ssh_keepalive_interval') def mitogen_ssh_keepalive_count(self): return self._connection.get_task_var('mitogen_ssh_keepalive_count') def mitogen_machinectl_path(self): return self._connection.get_task_var('mitogen_machinectl_path') def mitogen_ssh_debug_level(self): return self._connection.get_task_var('mitogen_ssh_debug_level') def mitogen_ssh_compression(self): return self._connection.get_task_var('mitogen_ssh_compression') def extra_args(self): return self._connection.get_extra_args() def ansible_doas_exe(self): return ( self._connection.get_task_var('ansible_doas_exe') or os.environ.get('ANSIBLE_DOAS_EXE') ) class MitogenViaSpec(Spec): """ MitogenViaSpec takes most of its information from the HostVars of the running task. HostVars is a lightweight wrapper around VariableManager, so it is better to say that VariableManager.get_vars() is the ultimate source of MitogenViaSpec's information. Due to this, mitogen_via= hosts must have all their configuration information represented as host and group variables. We cannot use any per-task configuration, as all that data belongs to the real target host. Ansible uses all kinds of strange historical logic for calculating variables, including making their precedence configurable. MitogenViaSpec must ultimately reimplement all of that logic. It is likely that if you are having a configruation problem with connection delegation, the answer to your problem lies in the method implementations below! """ def __init__(self, inventory_name, host_vars, task_vars, become_method, become_user, play_context, action): """ :param str inventory_name: The inventory name of the intermediary machine, i.e. not the target machine. :param dict host_vars: The HostVars magic dictionary provided by Ansible in task_vars. :param dict host_vars: The HostVars magic dictionary provided by Ansible in task_vars. :param str become_method: If the mitogen_via= spec included a become method, the method it specifies. :param str become_user: If the mitogen_via= spec included a become user, the user it specifies. :param PlayContext play_context: For some global values **only**, the PlayContext used to describe the real target machine. Values from this object are **strictly restricted** to values that are Ansible-global, e.g. the passwords specified interactively. :param ActionModuleMixin action: Backref to the ActionModuleMixin required for ansible interpreter discovery """ self._inventory_name = inventory_name self._host_vars = host_vars self._task_vars = task_vars self._become_method = become_method self._become_user = become_user # Dangerous! You may find a variable you want in this object, but it's # almost certainly for the wrong machine! self._dangerous_play_context = play_context self._action = action def transport(self): return ( self._host_vars.get('ansible_connection') or C.DEFAULT_TRANSPORT ) def inventory_name(self): return self._inventory_name def remote_addr(self): # play_context.py::MAGIC_VARIABLE_MAPPING return ( self._host_vars.get('ansible_ssh_host') or self._host_vars.get('ansible_host') or self._inventory_name ) def remote_user(self): return ( self._host_vars.get('ansible_ssh_user') or self._host_vars.get('ansible_user') or C.DEFAULT_REMOTE_USER ) def become(self): return bool(self._become_user) def become_method(self): return ( self._become_method or self._host_vars.get('ansible_become_method') or C.DEFAULT_BECOME_METHOD ) def become_user(self): return self._become_user def become_pass(self): return optional_secret( self._host_vars.get('ansible_become_password') or self._host_vars.get('ansible_become_pass') ) def password(self): return optional_secret( self._host_vars.get('ansible_ssh_pass') or self._host_vars.get('ansible_password') ) def port(self): return ( self._host_vars.get('ansible_ssh_port') or self._host_vars.get('ansible_port') or C.DEFAULT_REMOTE_PORT ) def python_path(self): s = self._host_vars.get('ansible_python_interpreter') # #511, #536: executor/module_common.py::_get_shebang() hard-wires # "/usr/bin/python" as the default interpreter path if no other # interpreter is specified. return parse_python_path( s or '/usr/bin/python', task_vars=self._task_vars, action=self._action) def private_key_file(self): # TODO: must come from PlayContext too. return ( self._host_vars.get('ansible_ssh_private_key_file') or self._host_vars.get('ansible_private_key_file') or C.DEFAULT_PRIVATE_KEY_FILE ) def ssh_executable(self): return ( self._host_vars.get('ansible_ssh_executable') or C.ANSIBLE_SSH_EXECUTABLE ) def timeout(self): # TODO: must come from PlayContext too. return C.DEFAULT_TIMEOUT def ansible_ssh_timeout(self): return ( self._host_vars.get('ansible_timeout') or self._host_vars.get('ansible_ssh_timeout') or self.timeout() ) def ssh_args(self): return [ mitogen.core.to_text(term) for s in ( ( self._host_vars.get('ansible_ssh_args') or getattr(C, 'ANSIBLE_SSH_ARGS', None) or os.environ.get('ANSIBLE_SSH_ARGS') # TODO: ini entry. older versions. ), ( self._host_vars.get('ansible_ssh_common_args') or os.environ.get('ANSIBLE_SSH_COMMON_ARGS') # TODO: ini entry. ), ( self._host_vars.get('ansible_ssh_extra_args') or os.environ.get('ANSIBLE_SSH_EXTRA_ARGS') # TODO: ini entry. ), ) for term in ansible.utils.shlex.shlex_split(s) if s ] def become_exe(self): return ( self._host_vars.get('ansible_become_exe') or C.DEFAULT_BECOME_EXE ) def sudo_args(self): return [ mitogen.core.to_text(term) for s in ( self._host_vars.get('ansible_sudo_flags') or '', self._host_vars.get('ansible_become_flags') or '', ) for term in ansible.utils.shlex.shlex_split(s) ] def mitogen_via(self): return self._host_vars.get('mitogen_via') def mitogen_kind(self): return self._host_vars.get('mitogen_kind') def mitogen_mask_remote_name(self): return self._host_vars.get('mitogen_mask_remote_name') def mitogen_buildah_path(self): return self._host_vars.get('mitogen_buildah_path') def mitogen_docker_path(self): return self._host_vars.get('mitogen_docker_path') def mitogen_kubectl_path(self): return self._host_vars.get('mitogen_kubectl_path') def mitogen_lxc_path(self): return self.host_vars.get('mitogen_lxc_path') def mitogen_lxc_attach_path(self): return self._host_vars.get('mitogen_lxc_attach_path') def mitogen_lxc_info_path(self): return self._host_vars.get('mitogen_lxc_info_path') def mitogen_ssh_keepalive_interval(self): return self._host_vars.get('mitogen_ssh_keepalive_interval') def mitogen_ssh_keepalive_count(self): return self._host_vars.get('mitogen_ssh_keepalive_count') def mitogen_machinectl_path(self): return self._host_vars.get('mitogen_machinectl_path') def mitogen_ssh_debug_level(self): return self._host_vars.get('mitogen_ssh_debug_level') def mitogen_ssh_compression(self): return self._host_vars.get('mitogen_ssh_compression') def extra_args(self): return [] # TODO def ansible_doas_exe(self): return ( self._host_vars.get('ansible_doas_exe') or os.environ.get('ANSIBLE_DOAS_EXE') )