From 28cd17cf56ec573ad92a79b3566730c5230cdd82 Mon Sep 17 00:00:00 2001 From: David Wilson Date: Fri, 30 Mar 2018 15:55:38 +0545 Subject: [PATCH] issue #106: import skeletal new executor. --- ansible_mitogen/executor.py | 287 ++++++++++++++++++++++++++++++++++++ 1 file changed, 287 insertions(+) create mode 100644 ansible_mitogen/executor.py diff --git a/ansible_mitogen/executor.py b/ansible_mitogen/executor.py new file mode 100644 index 00000000..00e91d05 --- /dev/null +++ b/ansible_mitogen/executor.py @@ -0,0 +1,287 @@ +# 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 json +import os +import tempfile + +import ansible_mitogen.helpers + +try: + from shlex import quote as shlex_quote +except ImportError: + from pipes import quote as shlex_quote + +# Prevent accidental import of an Ansible module from hanging on stdin read. +import ansible.module_utils.basic +ansible.module_utils.basic._ANSIBLE_ARGS = '{}' + + +class Exit(Exception): + """ + Raised when a module exits with success. + """ + def __init__(self, dct): + self.dct = dct + + +class ModuleError(Exception): + """ + Raised when a module voluntarily indicates failure via .fail_json(). + """ + def __init__(self, msg, dct): + Exception.__init__(self, msg) + self.dct = dct + + +class TemporaryEnvironment(object): + def __init__(self, env=None): + self.original = os.environ.copy() + self.env = env or {} + os.environ.update((k, str(v)) for k, v in self.env.iteritems()) + + def revert(self): + os.environ.clear() + os.environ.update(self.original) + + +class MethodOverrides(object): + @staticmethod + def exit_json(self, **kwargs): + """ + Replace AnsibleModule.exit_json() with something that doesn't try to + kill the process or JSON-encode the result dictionary. Instead, cause + Exit to be raised, with a `dct` attribute containing the successful + result dictionary. + """ + self.add_path_info(kwargs) + kwargs.setdefault('changed', False) + kwargs.setdefault('invocation', { + 'module_args': self.params + }) + kwargs = ansible.module_utils.basic.remove_values( + kwargs, + self.no_log_values, + ) + self.do_cleanup_files() + raise Exit(kwargs) + + @staticmethod + def fail_json(self, **kwargs): + """ + Replace AnsibleModule.fail_json() with something that raises + ModuleError, which includes a `dct` attribute. + """ + self.add_path_info(kwargs) + kwargs.setdefault('failed', True) + kwargs.setdefault('invocation', { + 'module_args': self.params + }) + kwargs = ansible.module_utils.basic.remove_values( + kwargs, + self.no_log_values, + ) + self.do_cleanup_files() + raise ModuleError(kwargs.get('msg'), kwargs) + + klass = ansible.module_utils.basic.AnsibleModule + + def __init__(self): + self._original_exit_json = self.klass.exit_json + self._original_fail_json = self.klass.fail_json + self.klass.exit_json = self.exit_json + self.klass.fail_json = self.fail_json + + def revert(self): + self.klass.exit_json = self._original_exit_json + self.klass.fail_json = self._original_fail_json + + +class ModuleArguments(object): + """ + Patch the ansible.module_utils.basic global arguments variable on + construction, and revert the changes on call to :meth:`revert`. + """ + def __init__(self, args): + self.original = ansible.module_utils.basic._ANSIBLE_ARGS + ansible.module_utils.basic._ANSIBLE_ARGS = json.dumps({ + 'ANSIBLE_MODULE_ARGS': args + }) + + def revert(self): + ansible.module_utils.basic._ANSIBLE_ARGS = self._original_args + + +class Runner(object): + def __init__(self, module, raw_params=None, args=None, env=None, + runner_params=None): + if args is None: + args = {} + if raw_params is not None: + args['_raw_params'] = raw_params + if runner_params is None: + runner_params = {} + + self.module = module + self.raw_params = raw_params + self.args = args + self.env = env + self.runner_params = runner_params + + def setup(self): + self._env = TemporaryEnvironment(self.env) + + def revert(self): + self._env.revert() + + def _run(self): + raise NotImplementedError() + + def run(self): + """ + Set up the process environment in preparation for running an Ansible + module. This monkey-patches the Ansible libraries in various places to + prevent it from trying to kill the process on completion, and to + prevent it from reading sys.stdin. + """ + self.setup() + try: + return self._run() + finally: + self.revert() + + +class PythonRunner(object): + """ + Execute a new-style Ansible module, where Module Replacer-related tricks + aren't required. + """ + def setup(self): + super(PythonRunner, self).setup() + self._overrides = MethodOverrides() + self._args = ModuleArguments(self.args) + + def revert(self): + super(PythonRunner, self).revert() + self._args.revert() + self._overrides.revert() + + def _run(self): + try: + mod = __import__(self.module, {}, {}, ['']) + # Ansible modules begin execution on import. Thus the above + # __import__ will cause either Exit or ModuleError to be raised. If + # we reach the line below, the module did not execute and must + # already have been imported for a previous invocation, so we need + # to invoke main explicitly. + mod.main() + except (Exit, ModuleError), e: + return json.dumps(e.dct) + + assert False, "Module returned no result." + + +class BinaryRunner(object): + def setup(self): + super(BinaryRunner, self).setup() + self._setup_binary() + self._setup_args() + + def _get_binary(self): + """ + Fetch the module binary from the master if necessary. + """ + return ansible_mitogen.helpers.get_file( + path=self.runner_params['path'], + ) + + def _get_args(self): + """ + Return the module arguments formatted as JSON. + """ + return json.dumps(self.args) + + def _setup_program(self): + """ + Create a temporary file containing the program code. The code is + fetched via :meth:`_get_binary`. + """ + self.bin_fp = tempfile.NamedTemporaryFile( + prefix='ansible_mitogen', + suffix='-binary', + ) + self.bin_fp.write(self._get_binary()) + self.bin_fp.flush() + os.chmod(self.fp.name, int('0700', 8)) + + def _setup_args(self): + """ + Create a temporary file containing the module's arguments. The + arguments are formatted via :meth:`_get_args`. + """ + self.args_fp = tempfile.NamedTemporaryFile( + prefix='ansible_mitogen', + suffix='-args', + ) + self.args_fp.write(self._get_args()) + self.args_fp.flush() + + def revert(self): + """ + Delete the temporary binary and argument files. + """ + self.args_fp.close() + self.bin_fp.close() + super(BinaryRunner, self).revert() + + def _run(self): + rc, stdout, stderr = ansible_mitogen.helpers.exec_args( + args=[self.bin_fp.name, self.args_fp.name], + ) + # ... + assert 0 + + +class WantJsonRunner(BinaryRunner): + def _get_binary(self): + s = super(WantJsonRunner, self)._get_binary() + # fix up shebang. + return s + + +class OldStyleRunner(BinaryRunner): + def _get_args(self): + """ + Mimic the argument formatting behaviour of + ActionBase._execute_module(). + """ + return ' '.join( + '%s=%s' % (key, shlex_quote(str(self.args[key]))) + for key in self.args + )