TripleO Ansible project repository. Contains playbooks for use with TripleO OpenStack deployments.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

357 lines
14 KiB

# Copyright 2020 Red Hat, Inc.
# All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
__metaclass__ = type
import os
import time
from ansible import constants as C
from ansible.errors import AnsibleError
from ansible.module_utils._text import to_text
from ansible.template import Templar
from ansible.utils.display import Display
import importlib.util
BASESPEC = importlib.util.spec_from_file_location(
os.path.join(os.path.dirname(__file__), '')
BASE = importlib.util.module_from_spec(BASESPEC)
except ImportError:
import imp
BASE = imp.load_source(
os.path.join(os.path.dirname(__file__), '')
strategy: tripleo_free
short_description: TripleO specific free strategy
- Based on the 'free' strategy from Ansible
- Logic broken up to allow for future improvements/extending
- Will fail playbook if any hosts have a failure during the
execution and any_errors_fatal is true (free does not do this).
- Should be backwards compatible for Ansible 2.8
- Handles run_once to only invoke the task a single time for a
given run. It should be noted that run_once does not ensure the
task actually is successful but rather that it is only triggered
once time for the host groups. If the task fails, the playbook
will fail at the end of the play but there is no assurance that
the task will actually complete successfully for a given playbook
execution. Other tasks will continue on the other hosts.
version_added: "2.9"
author: Alex Schultz <>
display = Display()
class TripleoFreeBreak(Exception):
"""Exception used to break loops"""
class TripleoFreeContinue(Exception):
"""Exception used to continue loops"""
class StrategyModule(BASE.TripleoBase):
# this strategy handles throttling
def __init__(self, *args, **kwargs):
super(StrategyModule, self).__init__(*args, **kwargs)
self._last_host = 0
self._workers_free = 0
self._run_once_tasks = set()
def _filter_notified_hosts(self, notified_hosts):
"""Filter notified hosts"""
return [host for host in notified_hosts
if host in self._flushed_hosts and self._flushed_hosts[host]]
def _increment_last_host(self):
"""Increment last host pointer
If the last host pointer exceeds the number of hosts, we set it back to
zero so we can start checking again with the first host
self._last_host += 1
self._debug('last_host is {}'.format(self._last_host))
if self._last_host > len(self._hosts_left) - 1:
self._debug('resetting last host')
self._last_host = 0
def _check_throttle(self, throttle, task):
"""Check if we should throttle"""
if throttle > 0:
same_task = 0
for worker in self._workers:
if (worker and worker.is_alive()
and worker._task._uuid == task._uuid):
same_task += 1
if same_task >= throttle:
return True
return False
def _check_failures(self, results):
"""Check results for failures
If any errors are fatal, kill the playbook at the end of
execution. All non-failed hosts will continue to run the
playbook but it won't move on to the next playbook. This
function returns True if there were failures and False if
there are no failures.
fail_lookup = self._get_current_failures()
if self._any_errors_fatal:
for res in results:
if ((res.is_failed() or res._task.action == 'meta')
and self._iterator.is_failed(res._host)
and self._check_fail_percent(res._host, fail_lookup)):
return True
return False
def _send_task_callback(self, task, templar):
"""Send task start callback"""
name =
try: = to_text(templar.template(,
except Exception:
self._debug('templating failed')
is_conditional=False) = name
def _advance_host(self, host, task):
"""Advance the host's task as necessary"""
self._debug('_advance_host {}'.format(host))
host_name = host.get_name()
# build get_vars call params
vars_params = {'play': self._iterator._play,
'host': host,
'task': task}
# If we have >= 2.9 we can use the hosts cache
if self._has_hosts_cache:
vars_params['_hosts'] = self._hosts_cache
if self._has_hosts_cache_all:
vars_params['_hosts_all'] = self._hosts_cache_all
task_vars = self._variable_manager.get_vars(**vars_params)
templar = Templar(loader=self._loader, variables=task_vars)
# if task has a throttle attribute, check throttle e.g. ansible > 2.9
throttle = getattr(task, 'throttle', None)
if throttle is not None:
throttle = int(templar.template(throttle))
except Exception as e:
raise AnsibleError("Failed to throttle: {}".format(e),
if self._check_throttle(throttle, task):
raise TripleoFreeBreak()
# _blocked_hosts is used in the base strategy to keep track of hosts in
# that have tasks in queue
self._blocked_hosts[host_name] = True
# Refetch the task without peek
(_, task) = self._iterator.get_next_task_for_host(host)
action = self._get_action(task)
try: = to_text(templar.template(,
except Exception:
display.warning('templating of task name failed', host=host_name)
# run once doesn't work with free because we run all of them
run_once = (templar.template(task.run_once) or action
and getattr(action, 'BYPASS_HOST_LOOP', False))
if run_once:
display.warning('tripleo_free run_once does not ensure a task '
'is successful for a given playbook but rather '
'it is only attempted to execute once.')
if action and getattr(action, 'BYPASS_HOST_LOOP', False):
raise AnsibleError('Cannot bypass host loop with strategy')
if task._uuid in self._run_once_tasks:
# If the task was previously executed, just drop it
# by clearing the blocked host and telling the parent
# function to continue.
self._debug("Skipping run_once task {} on {}".format(
task._uuid, host))
del self._blocked_hosts[host_name]
raise TripleoFreeContinue()
# handle role deduplication logic
if task._role and task._role.has_run(host):
if (task._role._metadata is None or task._role._metadata
and not task._role._metadata.allow_duplicates):
del self._blocked_hosts[host_name]
raise TripleoFreeContinue()
if task.action == 'meta':
self._execute_meta(task, self._play_context, self._iterator,
self._blocked_hosts[host_name] = False
if not self._step or self._take_step(task, host_name):
if self._get_task_errors_fatal(task, templar):
display.warning('any_errors_fatal only stops any future '
'tasks running on the host that fails '
'with the tripleo_free strategy.')
self._any_errors_fatal = True
self._send_task_callback(task, templar)
self._queue_task(host, task, task_vars, self._play_context)
self._workers_free -= 1
del task_vars
return True
def process_work(self):
"""Run pending tasks"""
result = self._tqm.RUN_OK
start_host = self._last_host
self._strat_results = []
while True:
self._debug('process_work loop')
host = self._hosts_left[self._last_host]
host_name = host.get_name()
(s, t) = self._iterator.get_next_task_for_host(host, peek=True)
self._print("host: {}, task: {}".format(host, t))
if host_name not in self._tqm._unreachable_hosts and t:
self._debug('{} has work to do, has_work = True'.format(
self._has_work = True
if not self._blocked_hosts.get(host_name, False):
self._advance_host(host, t)
except TripleoFreeBreak:
except TripleoFreeContinue:
self._print('{} still blocked'.format(host_name))
self._debug('{} is unreachable or no task'.format(host_name))
# handle host pinned by going back to the start and waiting
# for the next free host
if (self._host_pinned and self._workers_free == 0
and self._has_work):
self._last_host = start_host
if self._last_host == start_host:
self._debug('We hit the start host, break our loop')
self._debug('pending results....')
results = self._process_pending_results(self._iterator)
self._debug('results: {}'.format(results))
if self._check_failures(results):
# NOTE(mwhahaha): this is the bit of code that the upstream free
# does not do
result |= self._tqm.RUN_FAILED_BREAK_PLAY
self._workers_free += len(results)
self._debug('update connections....')
return result
def run(self, iterator, play_context):
"""Run out strategy"""
self._iterator = iterator
self._play_context = play_context
self._has_work = True
self._workers_free = len(self._workers)
result = self._tqm.RUN_OK
# check for < 2.9 and set vars so we know if we can use hosts cache
if getattr(self, '_set_hosts_cache', False):
self._has_hosts_cache = True
if getattr(self, '_set_hosts_cache_all', False):
self._has_hosts_cache_all = True
# while we still have tasks and ansible is still running
while self._has_work and not self._tqm._terminated:
self._has_work = False
self._debug('play: {}'.format(self._iterator._play))
# get the hosts with tasks
self._hosts_left = self.get_hosts_left(self._iterator)
if len(self._hosts_left) == 0:
# check if we previously had an error...
if result == self._tqm.RUN_OK:
# by setting this to false, the parent run function
# will determine if the run was ok based on a check
# of the unreachable/failed hosts.
result = False
# do work
result |= self.process_work()
# handle includes
include_result = self.process_includes(self._strat_results)
if self._any_errors_fatal and not include_result:
# NOTE(mwhahaha): This bit of code fails the playbook if
# an include fails. Upstream free does not have this today
display.error('An include failure occurred, we will not '
'continue to process after this play '
result |= self._tqm.RUN_FAILED_BREAK_PLAY
except (IOError, EOFError) as e:
display.error("Exception while running task loop: "
return self._tqm.RUN_UNKNOWN_ERROR
self._debug('sleeping... {}'.format(
# wait for any pending results
_ = self._wait_on_pending_results(iterator)
# call parent run to handle status
return super(StrategyModule, self).run(self._iterator,