# Copyright: (c) 2020, quidame # GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt) from __future__ import absolute_import, division, print_function __metaclass__ = type import time from ansible.plugins.action import ActionBase from ansible.errors import AnsibleActionFail, AnsibleConnectionFailure from ansible.utils.vars import merge_hash from ansible.utils.display import Display display = Display() class ActionModule(ActionBase): # Keep internal params away from user interactions _VALID_ARGS = frozenset(('path', 'state', 'table', 'noflush', 'counters', 'modprobe', 'ip_version', 'wait')) DEFAULT_SUDOABLE = True MSG_ERROR__ASYNC_AND_POLL_NOT_ZERO = ( "This module doesn't support async>0 and poll>0 when its 'state' param " "is set to 'restored'. To enable its rollback feature (that needs the " "module to run asynchronously on the remote), please set task attribute " "'poll' (=%s) to 0, and 'async' (=%s) to a value >2 and not greater than " "'ansible_timeout' (=%s) (recommended).") MSG_WARNING__NO_ASYNC_IS_NO_ROLLBACK = ( "Attempts to restore iptables state without rollback in case of mistake " "may lead the ansible controller to loose access to the hosts and never " "regain it before fixing firewall rules through a serial console, or any " "other way except SSH. Please set task attribute 'poll' (=%s) to 0, and " "'async' (=%s) to a value >2 and not greater than 'ansible_timeout' (=%s) " "(recommended).") MSG_WARNING__ASYNC_GREATER_THAN_TIMEOUT = ( "You attempt to restore iptables state with rollback in case of mistake, " "but with settings that will lead this rollback to happen AFTER that the " "controller will reach its own timeout. Please set task attribute 'poll' " "(=%s) to 0, and 'async' (=%s) to a value >2 and not greater than " "'ansible_timeout' (=%s) (recommended).") def _async_result(self, module_args, task_vars, timeout): ''' Retrieve results of the asynchonous task, and display them in place of the async wrapper results (those with the ansible_job_id key). ''' # At least one iteration is required, even if timeout is 0. for dummy in range(max(1, timeout)): async_result = self._execute_module( module_name='ansible.builtin.async_status', module_args=module_args, task_vars=task_vars, wrap_async=False) if async_result['finished'] == 1: break time.sleep(min(1, timeout)) return async_result def run(self, tmp=None, task_vars=None): self._supports_check_mode = True self._supports_async = True result = super(ActionModule, self).run(tmp, task_vars) del tmp # tmp no longer has any effect if not result.get('skipped'): # FUTURE: better to let _execute_module calculate this internally? wrap_async = self._task.async_val and not self._connection.has_native_async # Set short names for values we'll have to compare or reuse task_poll = self._task.poll task_async = self._task.async_val check_mode = self._play_context.check_mode max_timeout = self._connection._play_context.timeout module_args = self._task.args if module_args.get('state', None) == 'restored': if not wrap_async: if not check_mode: display.warning(self.MSG_WARNING__NO_ASYNC_IS_NO_ROLLBACK % ( task_poll, task_async, max_timeout)) elif task_poll: raise AnsibleActionFail(self.MSG_ERROR__ASYNC_AND_POLL_NOT_ZERO % ( task_poll, task_async, max_timeout)) else: if task_async > max_timeout and not check_mode: display.warning(self.MSG_WARNING__ASYNC_GREATER_THAN_TIMEOUT % ( task_poll, task_async, max_timeout)) # inject the async directory based on the shell option into the # module args async_dir = self.get_shell_option('async_dir', default="~/.ansible_async") # Bind the loop max duration to consistent values on both # remote and local sides (if not the same, make the loop # longer on the controller); and set a backup file path. module_args['_timeout'] = task_async module_args['_back'] = '%s/iptables.state' % async_dir async_status_args = dict(_async_dir=async_dir) confirm_cmd = 'rm -f %s' % module_args['_back'] starter_cmd = 'touch %s.starter' % module_args['_back'] remaining_time = max(task_async, max_timeout) # do work! result = merge_hash(result, self._execute_module(module_args=module_args, task_vars=task_vars, wrap_async=wrap_async)) # Then the 3-steps "go ahead or rollback": # 1. Catch early errors of the module (in asynchronous task) if any. # Touch a file on the target to signal the module to process now. # 2. Reset connection to ensure a persistent one will not be reused. # 3. Confirm the restored state by removing the backup on the remote. # Retrieve the results of the asynchronous task to return them. if '_back' in module_args: async_status_args['jid'] = result.get('ansible_job_id', None) if async_status_args['jid'] is None: raise AnsibleActionFail("Unable to get 'ansible_job_id'.") # Catch early errors due to missing mandatory option, bad # option type/value, missing required system command, etc. result = merge_hash(result, self._async_result(async_status_args, task_vars, 0)) # The module is aware to not process the main iptables-restore # command before finding (and deleting) the 'starter' cookie on # the host, so the previous query will not reach ssh timeout. dummy = self._low_level_execute_command(starter_cmd, sudoable=self.DEFAULT_SUDOABLE) # As the main command is not yet executed on the target, here # 'finished' means 'failed before main command be executed'. if not result['finished']: try: self._connection.reset() except AttributeError: pass for dummy in range(max_timeout): time.sleep(1) remaining_time -= 1 # - AnsibleConnectionFailure covers rejected requests (i.e. # by rules with '--jump REJECT') # - ansible_timeout is able to cover dropped requests (due # to a rule or policy DROP) if not lower than async_val. try: dummy = self._low_level_execute_command(confirm_cmd, sudoable=self.DEFAULT_SUDOABLE) break except AnsibleConnectionFailure: continue result = merge_hash(result, self._async_result(async_status_args, task_vars, remaining_time)) # Cleanup async related stuff and internal params for key in ('ansible_job_id', 'results_file', 'started', 'finished'): if result.get(key): del result[key] if result.get('invocation', {}).get('module_args'): for key in ('_back', '_timeout', '_async_dir', 'jid'): if result['invocation']['module_args'].get(key): del result['invocation']['module_args'][key] async_status_args['mode'] = 'cleanup' dummy = self._execute_module( module_name='ansible.builtin.async_status', module_args=async_status_args, task_vars=task_vars, wrap_async=False) if not wrap_async: # remove a temporary path we created self._remove_tmp_path(self._connection._shell.tmpdir) return result