mitogen/ansible_mitogen/planner.py

577 lines
19 KiB
Python

# 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.
"""
Classes to detect each case from [0] and prepare arguments necessary for the
corresponding Runner class within the target, including preloading requisite
files/modules known missing.
[0] "Ansible Module Architecture", developing_program_flow_modules.html
"""
from __future__ import absolute_import
from __future__ import unicode_literals
import json
import logging
import os
import random
from ansible.executor import module_common
import ansible.errors
import ansible.module_utils
import ansible.release
import mitogen.core
import mitogen.select
import ansible_mitogen.loaders
import ansible_mitogen.parsing
import ansible_mitogen.target
LOG = logging.getLogger(__name__)
NO_METHOD_MSG = 'Mitogen: no invocation method found for: '
NO_INTERPRETER_MSG = 'module (%s) is missing interpreter line'
NO_MODULE_MSG = 'The module %s was not found in configured module paths.'
_planner_by_path = {}
class Invocation(object):
"""
Collect up a module's execution environment then use it to invoke
target.run_module() or helpers.run_module_async() in the target context.
"""
def __init__(self, action, connection, module_name, module_args,
task_vars, templar, env, wrap_async, timeout_secs):
#: ActionBase instance invoking the module. Required to access some
#: output postprocessing methods that don't belong in ActionBase at
#: all.
self.action = action
#: Ansible connection to use to contact the target. Must be an
#: ansible_mitogen connection.
self.connection = connection
#: Name of the module ('command', 'shell', etc.) to execute.
self.module_name = module_name
#: Final module arguments.
self.module_args = module_args
#: Task variables, needed to extract ansible_*_interpreter.
self.task_vars = task_vars
#: Templar, needed to extract ansible_*_interpreter.
self.templar = templar
#: Final module environment.
self.env = env
#: Boolean, if :py:data:`True`, launch the module asynchronously.
self.wrap_async = wrap_async
#: Integer, if >0, limit the time an asynchronous job may run for.
self.timeout_secs = timeout_secs
#: Initially ``None``, but set by :func:`invoke`. The path on the
#: master to the module's implementation file.
self.module_path = None
#: Initially ``None``, but set by :func:`invoke`. The raw source or
#: binary contents of the module.
self._module_source = None
def get_module_source(self):
if self._module_source is None:
self._module_source = read_file(self.module_path)
return self._module_source
def __repr__(self):
return 'Invocation(module_name=%s)' % (self.module_name,)
class Planner(object):
"""
A Planner receives a module name and the contents of its implementation
file, indicates whether or not it understands how to run the module, and
exports a method to run the module.
"""
def __init__(self, invocation):
self._inv = invocation
@classmethod
def detect(cls, path, source):
"""
Return true if the supplied `invocation` matches the module type
implemented by this planner.
"""
raise NotImplementedError()
def should_fork(self):
"""
Asynchronous tasks must always be forked.
"""
return self._inv.wrap_async
def get_push_files(self):
"""
Return a list of files that should be propagated to the target context
using PushFileService. The default implementation pushes nothing.
"""
return []
def get_module_deps(self):
"""
Return a list of the Python module names imported by the module.
"""
return []
def get_kwargs(self, **kwargs):
"""
If :meth:`detect` returned :data:`True`, plan for the module's
execution, including granting access to or delivering any files to it
that are known to be absent, and finally return a dict::
{
# Name of the class from runners.py that implements the
# target-side execution of this module type.
"runner_name": "...",
# Remaining keys are passed to the constructor of the class
# named by `runner_name`.
}
"""
binding = self._inv.connection.get_binding()
new = dict((mitogen.core.UnicodeType(k), kwargs[k])
for k in kwargs)
new.setdefault('good_temp_dir',
self._inv.connection.get_good_temp_dir())
new.setdefault('cwd', self._inv.connection.get_default_cwd())
new.setdefault('extra_env', self._inv.connection.get_default_env())
new.setdefault('emulate_tty', True)
new.setdefault('service_context', binding.get_child_service_context())
return new
def __repr__(self):
return '%s()' % (type(self).__name__,)
class BinaryPlanner(Planner):
"""
Binary modules take their arguments and will return data to Ansible in the
same way as want JSON modules.
"""
runner_name = 'BinaryRunner'
@classmethod
def detect(cls, path, source):
return module_common._is_binary(source)
def get_push_files(self):
return [mitogen.core.to_text(self._inv.module_path)]
def get_kwargs(self, **kwargs):
return super(BinaryPlanner, self).get_kwargs(
runner_name=self.runner_name,
module=self._inv.module_name,
path=self._inv.module_path,
json_args=json.dumps(self._inv.module_args),
env=self._inv.env,
**kwargs
)
class ScriptPlanner(BinaryPlanner):
"""
Common functionality for script module planners -- handle interpreter
detection and rewrite.
"""
def _rewrite_interpreter(self, path):
"""
Given the original interpreter binary extracted from the script's
interpreter line, look up the associated `ansible_*_interpreter`
variable, render it and return it.
:param str path:
Absolute UNIX path to original interpreter.
:returns:
Shell fragment prefix used to execute the script via "/bin/sh -c".
While `ansible_*_interpreter` documentation suggests shell isn't
involved here, the vanilla implementation uses it and that use is
exploited in common playbooks.
"""
key = u'ansible_%s_interpreter' % os.path.basename(path).strip()
try:
template = self._inv.task_vars[key]
except KeyError:
return path
return mitogen.utils.cast(self._inv.templar.template(template))
def _get_interpreter(self):
path, arg = ansible_mitogen.parsing.parse_hashbang(
self._inv.get_module_source()
)
if path is None:
raise ansible.errors.AnsibleError(NO_INTERPRETER_MSG % (
self._inv.module_name,
))
fragment = self._rewrite_interpreter(path)
if arg:
fragment += ' ' + arg
return fragment, path.startswith('python')
def get_kwargs(self, **kwargs):
interpreter_fragment, is_python = self._get_interpreter()
return super(ScriptPlanner, self).get_kwargs(
interpreter_fragment=interpreter_fragment,
is_python=is_python,
**kwargs
)
class JsonArgsPlanner(ScriptPlanner):
"""
Script that has its interpreter directive and the task arguments
substituted into its source as a JSON string.
"""
runner_name = 'JsonArgsRunner'
@classmethod
def detect(cls, path, source):
return module_common.REPLACER_JSONARGS in source
class WantJsonPlanner(ScriptPlanner):
"""
If a module has the string WANT_JSON in it anywhere, Ansible treats it as a
non-native module that accepts a filename as its only command line
parameter. The filename is for a temporary file containing a JSON string
containing the module's parameters. The module needs to open the file, read
and parse the parameters, operate on the data, and print its return data as
a JSON encoded dictionary to stdout before exiting.
These types of modules are self-contained entities. As of Ansible 2.1,
Ansible only modifies them to change a shebang line if present.
"""
runner_name = 'WantJsonRunner'
@classmethod
def detect(cls, path, source):
return b'WANT_JSON' in source
class NewStylePlanner(ScriptPlanner):
"""
The Ansiballz framework differs from module replacer in that it uses real
Python imports of things in ansible/module_utils instead of merely
preprocessing the module.
"""
runner_name = 'NewStyleRunner'
marker = b'from ansible.module_utils.'
@classmethod
def detect(cls, path, source):
return cls.marker in source
def _get_interpreter(self):
return None, None
def get_push_files(self):
return super(NewStylePlanner, self).get_push_files() + [
mitogen.core.to_text(path)
for fullname, path, is_pkg in self.get_module_map()['custom']
]
def get_module_deps(self):
return self.get_module_map()['builtin']
#: Module names appearing in this set always require forking, usually due
#: to some terminal leakage that cannot be worked around in any sane
#: manner.
ALWAYS_FORK_MODULES = frozenset([
'dnf', # issue #280; py-dnf/hawkey need therapy
'firewalld', # issue #570: ansible module_utils caches dbus conn
])
def should_fork(self):
"""
In addition to asynchronous tasks, new-style modules should be forked
if:
* the user specifies mitogen_task_isolation=fork, or
* the new-style module has a custom module search path, or
* the module is known to leak like a sieve.
"""
return (
super(NewStylePlanner, self).should_fork() or
(self._inv.task_vars.get('mitogen_task_isolation') == 'fork') or
(self._inv.module_name in self.ALWAYS_FORK_MODULES) or
(len(self.get_module_map()['custom']) > 0)
)
def get_search_path(self):
return tuple(
path
for path in ansible_mitogen.loaders.module_utils_loader._get_paths(
subdirs=False
)
)
_module_map = None
def get_module_map(self):
if self._module_map is None:
binding = self._inv.connection.get_binding()
self._module_map = mitogen.service.call(
call_context=binding.get_service_context(),
service_name='ansible_mitogen.services.ModuleDepService',
method_name='scan',
module_name='ansible_module_%s' % (self._inv.module_name,),
module_path=self._inv.module_path,
search_path=self.get_search_path(),
builtin_path=module_common._MODULE_UTILS_PATH,
context=self._inv.connection.context,
)
return self._module_map
def get_kwargs(self):
return super(NewStylePlanner, self).get_kwargs(
module_map=self.get_module_map(),
py_module_name=py_modname_from_path(
self._inv.module_name,
self._inv.module_path,
),
)
class ReplacerPlanner(NewStylePlanner):
"""
The Module Replacer framework is the original framework implementing
new-style modules. It is essentially a preprocessor (like the C
Preprocessor for those familiar with that programming language). It does
straight substitutions of specific substring patterns in the module file.
There are two types of substitutions.
* Replacements that only happen in the module file. These are public
replacement strings that modules can utilize to get helpful boilerplate
or access to arguments.
"from ansible.module_utils.MOD_LIB_NAME import *" is replaced with the
contents of the ansible/module_utils/MOD_LIB_NAME.py. These should only
be used with new-style Python modules.
"#<<INCLUDE_ANSIBLE_MODULE_COMMON>>" is equivalent to
"from ansible.module_utils.basic import *" and should also only apply to
new-style Python modules.
"# POWERSHELL_COMMON" substitutes the contents of
"ansible/module_utils/powershell.ps1". It should only be used with
new-style Powershell modules.
"""
runner_name = 'ReplacerRunner'
@classmethod
def detect(cls, path, source):
return module_common.REPLACER in source
class OldStylePlanner(ScriptPlanner):
runner_name = 'OldStyleRunner'
@classmethod
def detect(cls, path, source):
# Everything else.
return True
_planners = [
BinaryPlanner,
# ReplacerPlanner,
NewStylePlanner,
JsonArgsPlanner,
WantJsonPlanner,
OldStylePlanner,
]
try:
_get_ansible_module_fqn = module_common._get_ansible_module_fqn
except AttributeError:
_get_ansible_module_fqn = None
def py_modname_from_path(name, path):
"""
Fetch the logical name of a new-style module as it might appear in
:data:`sys.modules` of the target's Python interpreter.
* For Ansible <2.7, this is an unpackaged module named like
"ansible_module_%s".
* For Ansible <2.9, this is an unpackaged module named like
"ansible.modules.%s"
* Since Ansible 2.9, modules appearing within a package have the original
package hierarchy approximated on the target, enabling relative imports
to function correctly. For example, "ansible.modules.system.setup".
"""
# 2.9+
if _get_ansible_module_fqn:
try:
return _get_ansible_module_fqn(path)
except ValueError:
pass
if ansible.__version__ < '2.7':
return 'ansible_module_' + name
return 'ansible.modules.' + name
def read_file(path):
fd = os.open(path, os.O_RDONLY)
try:
bits = []
chunk = True
while True:
chunk = os.read(fd, 65536)
if not chunk:
break
bits.append(chunk)
finally:
os.close(fd)
return mitogen.core.b('').join(bits)
def _propagate_deps(invocation, planner, context):
binding = invocation.connection.get_binding()
mitogen.service.call(
call_context=binding.get_service_context(),
service_name='mitogen.service.PushFileService',
method_name='propagate_paths_and_modules',
context=context,
paths=planner.get_push_files(),
modules=planner.get_module_deps(),
)
def _invoke_async_task(invocation, planner):
job_id = '%016x' % random.randint(0, 2**64)
context = invocation.connection.spawn_isolated_child()
_propagate_deps(invocation, planner, context)
with mitogen.core.Receiver(context.router) as started_recv:
call_recv = context.call_async(
ansible_mitogen.target.run_module_async,
job_id=job_id,
timeout_secs=invocation.timeout_secs,
started_sender=started_recv.to_sender(),
kwargs=planner.get_kwargs(),
)
# Wait for run_module_async() to crash, or for AsyncRunner to indicate
# the job file has been written.
for msg in mitogen.select.Select([started_recv, call_recv]):
if msg.receiver is call_recv:
# It can only be an exception.
raise msg.unpickle()
break
return {
'stdout': json.dumps({
# modules/utilities/logic/async_wrapper.py::_run_module().
'changed': True,
'started': 1,
'finished': 0,
'ansible_job_id': job_id,
})
}
def _invoke_isolated_task(invocation, planner):
context = invocation.connection.spawn_isolated_child()
_propagate_deps(invocation, planner, context)
try:
return context.call(
ansible_mitogen.target.run_module,
kwargs=planner.get_kwargs(),
)
finally:
context.shutdown()
def _get_planner(name, path, source):
for klass in _planners:
if klass.detect(path, source):
LOG.debug('%r accepted %r (filename %r)', klass, name, path)
return klass
LOG.debug('%r rejected %r', klass, name)
raise ansible.errors.AnsibleError(NO_METHOD_MSG + repr(invocation))
def invoke(invocation):
"""
Find a Planner subclass corresponding to `invocation` and use it to invoke
the module.
:param Invocation invocation:
:returns:
Module return dict.
:raises ansible.errors.AnsibleError:
Unrecognized/unsupported module type.
"""
path = ansible_mitogen.loaders.module_loader.find_plugin(
invocation.module_name,
'',
)
if path is None:
raise ansible.errors.AnsibleError(NO_MODULE_MSG % (
invocation.module_name,
))
invocation.module_path = mitogen.core.to_text(path)
if invocation.module_path not in _planner_by_path:
_planner_by_path[invocation.module_path] = _get_planner(
invocation.module_name,
invocation.module_path,
invocation.get_module_source()
)
planner = _planner_by_path[invocation.module_path](invocation)
if invocation.wrap_async:
response = _invoke_async_task(invocation, planner)
elif planner.should_fork():
response = _invoke_isolated_task(invocation, planner)
else:
_propagate_deps(invocation, planner, invocation.connection.context)
response = invocation.connection.get_chain().call(
ansible_mitogen.target.run_module,
kwargs=planner.get_kwargs(),
)
return invocation.action._postprocess_response(response)