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mitogen/ansible_mitogen/mixins.py

324 lines
12 KiB
Python

# 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
import commands
import os
import pwd
import shutil
import tempfile
import traceback
import ansible
import ansible.plugins
import ansible.plugins.action
try:
from ansible.plugins.loader import module_loader
except ImportError: # Ansible<2.4
from ansible.plugins import module_loader
import mitogen.core
import mitogen.master
from mitogen.utils import cast
import ansible_mitogen.connection
import ansible_mitogen.helpers
from ansible.module_utils._text import to_text
def get_command_module_name(module_name):
"""
Given the name of an Ansible command module, return its canonical module
path within the ansible.
:param module_name:
"shell"
:return:
"ansible.modules.commands.shell"
"""
path = module_loader.find_plugin(module_name, '')
relpath = os.path.relpath(path, os.path.dirname(ansible.__file__))
root, _ = os.path.splitext(relpath)
return 'ansible.' + root.replace('/', '.')
class ActionModuleMixin(ansible.plugins.action.ActionBase):
"""
The Mitogen-patched PluginLoader dynamically mixes this into every action
class that Ansible attempts to load. It exists to override all the
assumptions built into the base action class that should really belong in
some middle layer, or at least in the connection layer.
Functionality is defined here for:
* Capturing the final set of task variables and giving Connection a chance
to update its idea of the correct execution environment, before any
attempt is made to call a Connection method. While it's not expected for
the interpreter to change on a per-task basis, Ansible permits this, and
so it must be supported.
* Overriding lots of methods that try to call out to shell for mundane
reasons, such as copying files around, changing file permissions,
creating temporary directories and suchlike.
* Short-circuiting any use of Ansiballz or related code for executing a
module remotely using shell commands and SSH.
* Short-circuiting most of the logic in dealing with the fact that Ansible
always runs become: tasks across at least the SSH user account and the
destination user account, and handling the security permission issues
that crop up due to this. Mitogen always runs a task completely within
the target user account, so it's not a problem for us.
"""
def __init__(self, task, connection, *args, **kwargs):
"""
Verify the received connection is really a Mitogen connection. If not,
transmute this instance back into the original unadorned base class.
This allows running the Mitogen strategy in mixed-target playbooks,
where some targets use SSH while others use WinRM or some fancier UNIX
connection plug-in. That's because when the Mitogen strategy is active,
ActionModuleMixin is unconditionally mixed into any action module that
is instantiated, and there is no direct way for the monkey-patch to
know what kind of connection will be used upfront.
"""
super(ActionModuleMixin, self).__init__(task, connection, *args, **kwargs)
if not isinstance(connection, ansible_mitogen.connection.Connection):
_, self.__class__ = type(self).__bases__
def run(self, tmp=None, task_vars=None):
"""
Override run() to notify Connection of task-specific data, so it has a
chance to know e.g. the Python interpreter in use.
"""
self._connection.on_action_run(task_vars)
return super(ActionModuleMixin, self).run(tmp, task_vars)
def call(self, func, *args, **kwargs):
"""
Arrange for a Python function to be called in the target context, which
should be some function from the standard library or
ansible_mitogen.helpers module. This junction point exists mainly as a
nice place to insert print statements during debugging.
"""
return self._connection.call(func, *args, **kwargs)
COMMAND_RESULT = {
'rc': 0,
'stdout': '',
'stdout_lines': [],
'stderr': ''
}
def fake_shell(self, func, stdout=False):
"""
Execute a function and decorate its return value in the style of
_low_level_execute_command(). This produces a return value that looks
like some shell command was run, when really func() was implemented
entirely in Python.
If the function raises :py:class:`mitogen.core.CallError`, this will be
translated into a failed shell command with a non-zero exit status.
:param func:
Function invoked as `func()`.
:returns:
See :py:attr:`COMMAND_RESULT`.
"""
dct = self.COMMAND_RESULT.copy()
try:
rc = func()
if stdout:
dct['stdout'] = repr(rc)
except mitogen.core.CallError:
dct['rc'] = 1
dct['stderr'] = traceback.format_exc()
return dct
def _remote_file_exists(self, path):
"""
Determine if `path` exists by directly invoking os.path.exists() in the
target user account.
"""
return self.call(os.path.exists, path)
def _configure_module(self, module_name, module_args, task_vars=None):
"""
Mitogen does not use the Ansiballz framework. This call should never
happen when ActionMixin is active, so crash if it does.
"""
assert False, "_configure_module() should never be called."
def _is_pipelining_enabled(self, module_style, wrap_async=False):
"""
Mitogen does not use SSH pipelining. This call should never happen when
ActionMixin is active, so crash if it does.
"""
assert False, "_is_pipelining_enabled() should never be called."
def _make_tmp_path(self, remote_user=None):
"""
Replace the base implementation's use of shell to implement mkdtemp()
with an actual call to mkdtemp().
"""
path = self.call(tempfile.mkdtemp, prefix='ansible-mitogen-tmp-')
self._cleanup_remote_tmp = True
return path
def _remove_tmp_path(self, tmp_path):
"""
Replace the base implementation's invocation of rm -rf with a call to
shutil.rmtree().
"""
if self._should_remove_tmp_path(tmp_path):
return self.call(shutil.rmtree, tmp_path)
def _transfer_data(self, remote_path, data):
"""
This is used by the base implementation of _execute_module(), it should
never be called.
"""
assert False, "_transfer_data() should never be called."
def _fixup_perms2(self, remote_paths, remote_user=None, execute=True):
"""
Mitogen always executes ActionBase helper methods in the context of the
target user account, so it is never necessary to modify permissions
except to ensure the execute bit is set if requested.
"""
if execute:
return self._remote_chmod(remote_paths, mode='u+x')
return self.COMMAND_RESULT.copy()
def _remote_chmod(self, paths, mode, sudoable=False):
"""
Issue an asynchronous set_file_mode() call for every path in `paths`,
then format the resulting return value list with fake_shell().
"""
return self.fake_shell(lambda: mitogen.master.Select.all(
self._connection.call_async(
ansible_mitogen.helpers.set_file_mode, path, mode
)
for path in paths
))
def _remote_chown(self, paths, user, sudoable=False):
"""
Issue an asynchronous os.chown() call for every path in `paths`, then
format the resulting return value list with fake_shell().
"""
ent = self.call(pwd.getpwnam, user)
return self.fake_shell(lambda: mitogen.master.Select.all(
self._connection.call_async(
os.chown, path, ent.pw_uid, ent.pw_gid
)
for path in paths
))
def _remote_expand_user(self, path, sudoable=True):
"""
Replace the base implementation's attempt to emulate
os.path.expanduser() with an actual call to os.path.expanduser().
"""
if path.startswith('~'):
path = self.call(os.path.expanduser, path)
return path
def _execute_module(self, module_name=None, module_args=None, tmp=None,
task_vars=None, persist_files=False,
delete_remote_tmp=True, wrap_async=False):
"""
Collect up a module's execution environment then use it to invoke
helpers.run_module() or helpers.run_module_async() in the target
context.
"""
module_name = module_name or self._task.action
module_args = module_args or self._task.args
task_vars = task_vars or {}
self._update_module_args(module_name, module_args, task_vars)
if wrap_async:
helper = ansible_mitogen.helpers.run_module_async
else:
helper = ansible_mitogen.helpers.run_module
env = {}
self._compute_environment_string(env)
js = self.call(
helper,
get_command_module_name(module_name),
args=cast(module_args),
env=cast(env),
)
data = self._parse_returned_data({
'rc': 0,
'stdout': js,
'stdout_lines': [js],
'stderr': ''
})
# Cutpasted from the base implementation.
if 'stdout' in data and 'stdout_lines' not in data:
data['stdout_lines'] = (data['stdout'] or u'').splitlines()
if 'stderr' in data and 'stderr_lines' not in data:
data['stderr_lines'] = (data['stderr'] or u'').splitlines()
return data
def _low_level_execute_command(self, cmd, sudoable=True, in_data=None,
executable=None,
encoding_errors='surrogate_then_replace',
chdir=None):
"""
Replace the mad rat's nest of logic in the base implementation by
simply calling helpers.exec_command() in the target context.
"""
if executable is None: # executable defaults to False
executable = self._play_context.executable
if executable:
cmd = executable + ' -c ' + commands.mkarg(cmd)
rc, stdout, stderr = self.call(
ansible_mitogen.helpers.exec_command,
cast(cmd),
cast(in_data),
chdir=cast(chdir),
)
stdout_text = to_text(stdout, errors=encoding_errors)
return {
'rc': rc,
'stdout': stdout_text,
'stdout_lines': stdout_text.splitlines(),
'stderr': stderr,
}