community.general/lib/ansible/playbook.py

318 lines
11 KiB
Python
Executable File

# (c) 2012, Michael DeHaan <michael.dehaan@gmail.com>
#
# This file is part of Ansible
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ansible. If not, see <http://www.gnu.org/licenses/>.
#############################################
import ansible.runner
import ansible.constants as C
from ansible.utils import *
import yaml
import shlex
import os
#############################################
class PlayBook(object):
'''
runs an ansible playbook, given as a datastructure
or YAML filename. a playbook is a deployment, config
management, or automation based set of commands to
run in series.
multiple patterns do not execute simultaneously,
but tasks in each pattern do execute in parallel
according to the number of forks requested.
'''
def __init__(self,
playbook =None,
host_list =C.DEFAULT_HOST_LIST,
module_path =C.DEFAULT_MODULE_PATH,
forks =C.DEFAULT_FORKS,
timeout =C.DEFAULT_TIMEOUT,
remote_user =C.DEFAULT_REMOTE_USER,
remote_pass =C.DEFAULT_REMOTE_PASS,
verbose=False):
# TODO, once ansible-playbook is it's own script this will
# have much LESS parameters to the constructor and will
# read most everything per pattern from the playbook
# and this will be greatly simplified
self.host_list = host_list
self.module_path = module_path
self.forks = forks
self.timeout = timeout
self.remote_user = remote_user
self.remote_pass = remote_pass
self.verbose = verbose
# store the list of changes/invocations/failure counts
# as a dictionary of integers keyed off the hostname
self.processed = {}
self.dark = {}
self.changed = {}
self.invocations = {}
self.failures = {}
# playbook file can be passed in as a path or
# as file contents (to support API usage)
self.playbook = self._parse_playbook(playbook)
def _parse_playbook(self, playbook):
''' load YAML file, including handling for imported files '''
dirname = os.path.dirname(playbook)
playbook = yaml.load(file(playbook).read())
for play in playbook:
tasks = play.get('tasks',[])
handlers = play.get('handlers', [])
# process tasks in this file as well as imported tasks
new_tasks = []
for task in tasks:
if 'include' in task:
path = path_dwim(dirname, task['include'])
included = yaml.load(file(path).read())
for x in included:
new_tasks.append(x)
else:
new_tasks.append(task)
play['tasks'] = new_tasks
# process handlers as well as imported handlers
new_handlers = []
for handler in handlers:
if 'include' in handler:
path = path_dwim(dirname, handler['include'])
included = yaml.load(file(path).read())
for x in included:
new_handlers.append(x)
else:
new_handlers.append(handler)
play['handlers'] = new_handlers
return playbook
def run(self):
''' run all patterns in the playbook '''
# loop through all patterns and run them
for pattern in self.playbook:
self._run_pattern(pattern)
if self.verbose:
print "\n"
# summarize the results
results = {}
for host in self.processed.keys():
results[host] = {
'resources' : self.invocations.get(host, 0),
'changed' : self.changed.get(host, 0),
'dark' : self.dark.get(host, 0),
'failed' : self.failures.get(host, 0)
}
return results
def _prune_failed_hosts(self, host_list):
new_hosts = []
for x in host_list:
if not x in self.failures and not x in self.dark:
new_hosts.append(x)
return new_hosts
def _run_module(self, pattern, module, args, hosts, remote_user):
''' run a particular module step in a playbook '''
return ansible.runner.Runner(
pattern=pattern,
module_name=module,
module_args=args,
host_list=hosts,
forks=self.forks,
remote_pass=self.remote_pass,
module_path=self.module_path,
timeout=self.timeout,
remote_user=remote_user
).run()
def _run_task(self, pattern=None, task=None, host_list=None,
remote_user=None, handlers=None, conditional=False):
'''
run a single task in the playbook and
recursively run any subtasks.
'''
if host_list is None:
# pruned host lists occur when running triggered
# actions where not all hosts have changed
# though top-level tasks will pass in "None" here
host_list = self.host_list
(host_list, groups) = ansible.runner.Runner.parse_hosts(host_list)
# do not continue to run tasks on hosts that have had failures
host_list = self._prune_failed_hosts(host_list)
# load the module name and parameters from the task entry
name = task['name']
action = task['action']
# comment = task.get('comment', '')
tokens = shlex.split(action)
module_name = tokens[0]
module_args = tokens[1:]
# tasks can be direct (run on all nodes matching
# the pattern) or conditional, where they ran
# as the result of a change handler on a subset
# of all of the hosts
if self.verbose:
print task_start_msg(name, conditional)
# load up an appropriate ansible runner to
# run the task in parallel
results = self._run_module(pattern, module_name,
module_args, host_list, remote_user)
# if no hosts are matched, carry on, unlike /bin/ansible
# which would warn you about this
if results is None:
results = {}
# walk through the results and build up
# summary information about successes and
# failures. TODO: split into subfunction
dark = results.get("dark", {})
contacted = results.get("contacted", {})
for host, msg in dark.items():
self.processed[host] = 1
if self.verbose:
print "unreachable: [%s] => %s" % (host, msg)
if not host in self.dark:
self.dark[host] = 1
else:
self.dark[host] = self.dark[host] + 1
for host, results in contacted.items():
self.processed[host] = 1
if is_failed(results):
if self.verbose:
print "failed: [%s] => %s\n" % (host, smjson(results))
if not host in self.failures:
self.failures[host] = 1
else:
self.failures[host] = self.failures[host] + 1
else:
if self.verbose:
print "ok: [%s]\n" % host
if not host in self.invocations:
self.invocations[host] = 1
else:
self.invocations[host] = self.invocations[host] + 1
if results.get('changed', False):
if not host in self.changed:
self.changed[host] = 1
else:
self.changed[host] = self.changed[host] + 1
# flag which notify handlers need to be run
# this will be on a SUBSET of the actual host list. For instance
# a file might need to be written on only half of the nodes so
# we would only trigger restarting Apache on half of the nodes
subtasks = task.get('notify', [])
if len(subtasks) > 0:
for host, results in contacted.items():
if results.get('changed', False):
for subtask in subtasks:
self._flag_handler(handlers, subtask, host)
def _flag_handler(self, handlers, match_name, host):
'''
if a task has any notify elements, flag handlers for run
at end of execution cycle for hosts that have indicated
changes have been made
'''
# for all registered handlers in the ansible playbook
# for this particular pattern group
for x in handlers:
name = x['name']
if match_name == name:
# flag the handler with the list of hosts
# it needs to be run on, it will be run later
if not 'run' in x:
x['run'] = []
x['run'].append(host)
def _run_pattern(self, pg):
'''
run a list of tasks for a given pattern, in order
'''
# get configuration information about the pattern
pattern = pg['hosts']
tasks = pg['tasks']
handlers = pg['handlers']
user = pg.get('user', C.DEFAULT_REMOTE_USER)
self.host_list, groups = ansible.runner.Runner.parse_hosts(self.host_list)
if self.verbose:
print "PLAY [%s] ****************************\n" % pattern
# run all the top level tasks, these get run on every node
for task in tasks:
self._run_task(
pattern=pattern,
task=task,
handlers=handlers,
remote_user=user
)
# handlers only run on certain nodes, they are flagged by _flag_handlers
# above. They only run on nodes when things mark them as changed, and
# handlers only get run once. For instance, the system is designed
# such that multiple config files if changed can ask for an Apache restart
# but Apache will only be restarted once (at the end).
for task in handlers:
if type(task.get("run", None)) == list:
self._run_task(
pattern=pattern,
task=task,
handlers=handlers,
host_list=task.get('run',[]),
conditional=True,
remote_user=user
)
# end of execution for this particular pattern. Multiple patterns
# can be in a single playbook file