community.general/v2/ansible/executor/playbook_iterator.py
2014-11-08 01:44:21 -06:00

97 lines
3.8 KiB
Python

# (c) 2012-2014, 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/>.
# Make coding more python3-ish
from __future__ import (absolute_import, division, print_function)
__metaclass__ = type
class PlaybookState:
'''
A helper class, which keeps track of the task iteration
state for a given playbook. This is used in the PlaybookIterator
class on a per-host basis.
'''
def __init__(self, parent_iterator):
self._parent_iterator = parent_iterator
self._cur_play = 0
self._task_list = None
self._cur_task_pos = 0
def next(self):
'''
Determines and returns the next available task from the playbook,
advancing through the list of plays as it goes.
'''
while True:
# when we hit the end of the playbook entries list, we return
# None to indicate we're there
if self._cur_play > len(self._parent_iterator._playbook._entries) - 1:
return None
# initialize the task list by calling the .compile() method
# on the play, which will call compile() for all child objects
if self._task_list is None:
self._task_list = self._parent_iterator._playbook._entries[self._cur_play].compile()
# if we've hit the end of this plays task list, move on to the next
# and reset the position values for the next iteration
if self._cur_task_pos > len(self._task_list) - 1:
self._cur_play += 1
self._task_list = None
self._cur_task_pos = 0
continue
else:
# FIXME: do tag/conditional evaluation here and advance
# the task position if it should be skipped without
# returning a task
task = self._task_list[self._cur_task_pos]
self._cur_task_pos += 1
# Skip the task if it is the member of a role which has already
# been run, unless the role allows multiple executions
if task._role:
# FIXME: this should all be done via member functions
# instead of direct access to internal variables
if task._role.has_run() and not task._role._metadata._allow_duplicates:
continue
return task
class PlaybookIterator:
'''
The main iterator class, which keeps the state of the playbook
on a per-host basis using the above PlaybookState class.
'''
def __init__(self, inventory, log_manager, playbook):
self._playbook = playbook
self._log_manager = log_manager
self._host_entries = dict()
# build the per-host dictionary of playbook states
for host in inventory.get_hosts():
self._host_entries[host.get_name()] = PlaybookState(parent_iterator=self)
def get_next_task_for_host(self, host):
''' fetch the next task for the given host '''
if host.get_name() not in self._host_entries:
raise AnsibleError("invalid host specified for playbook iteration")
return self._host_entries[host.get_name()].next()