在ansible1.9的时候，API是一个非常简单的东西。官方说“it's pretty simple”，真是又pretty又simple。
import ansible.runner runner = ansible.runner.Runner( module_name='ping', module_args='', pattern='web*', forks=10) datastructure = runner.run()
到了ansible2.0以后，是“a bit more complicated”，Oh my，简直让人难受。
简洁和灵活是鱼和熊掌。
ansible2.0 API怎么用？
ansible2.0更贴近于ansible cli的常用命令执行方式，不同于上一版本只能发送单个命令或playbook；而更推荐用户在调用ansibleAPI的时候，将playbook的每个task拆分出来，获取每个task的结果。能够跟灵活处理在执行批量作业过程中的各种反馈。
将执行操作的队列模型，包含各类环境参数设置，归结到“ansible.executor.task_queue_manager”类中
将执行过程中的各个task的设置，或者说playbook中的编排内容，归结到“ansible.playbook.play”中
上述两个东西，几乎囊括了可以在执行过程中设置的所有参数，足够灵活，也让人抓狂，相当于需要自己写一个1.9版本中的runner。
他们的确也都是原生类，并非专用于外部调用。
ansible.executor.task_queue_manager
这是ansible的一个内部模块（ansible/executor/task_queue_manager.py）。初始化的源码如下：
class TaskQueueManager: ''' This class handles the multiprocessing requirements of Ansible by creating a pool of worker forks, a result handler fork, and a manager object with shared datastructures/queues for coordinating work between all processes. The queue manager is responsible for loading the play strategy plugin, which dispatches the Play's tasks to hosts. ''' def __init__(self, inventory, variable_manager, loader, options, passwords, stdout_callback=None, run_additional_callbacks=True, run_tree=False): self._inventory = inventory self._variable_manager = variable_manager self._loader = loader self._options = options self._stats = AggregateStats() self.passwords = passwords self._stdout_callback = stdout_callback self._run_additional_callbacks = run_additional_callbacks self._run_tree = run_tree self._callbacks_loaded = False self._callback_plugins = [] self._start_at_done = False self._result_prc = None ……
创建时，需要的主要参数包括：
inventory --> 由ansible.inventory模块创建，用于导入inventory文件
variable_manager --> 由ansible.vars模块创建，用于存储各类变量信息
loader --> 由ansible.parsing.dataloader模块创建，用于数据解析
options --> 存放各类配置信息的数据字典
passwords --> 登录密码，可设置加密信息
stdout_callback --> 回调函数
ansible.playbook.play
ansible.playbook是一个原生模块，既用于CLI也用于API。从源码可以看出来：
try: from __main__ import displayexcept ImportError: from ansible.utils.display import Display display = Display()
ansible.playbook.play（ansible/playbook/play.py）。初始化源码的介绍如下：
__all__ = ['Play']class Play(Base, Taggable, Become): """ A play is a language feature that represents a list of roles and/or task/handler blocks to execute on a given set of hosts. Usage: Play.load(datastructure) -> Play Play.something(...) """
最后，用task_queue_manager(play)来执行，老规矩，源码的官方解释。
def run(self, play): ''' Iterates over the roles/tasks in a play, using the given (or default) strategy for queueing tasks. The default is the linear strategy, which operates like classic Ansible by keeping all hosts in lock-step with a given task (meaning no hosts move on to the next task until all hosts are done with the current task). '''
一个完整的例子
# -*- coding:utf-8 -*-# !/usr/bin/env python## Author: Shawn.T# Email: shawntai.ds@gmail.com## this is the Interface package of Ansible2 API#from collections import namedtuplefrom ansible.parsing.dataloader import DataLoaderfrom ansible.vars import VariableManagerfrom ansible.inventory import Inventoryfrom ansible.playbook.play import Playfrom ansible.executor.task_queue_manager import TaskQueueManagerfrom tempfile import NamedTemporaryFileimport osclass AnsibleTask(object):
def __init__(self, targetHost):
Options = namedtuple( 'Options', [ 'listtags', 'listtasks', 'listhosts', 'syntax', 'connection','module_path', 'forks', 'remote_user', 'private_key_file', 'ssh_common_args', 'ssh_extra_args', 'sftp_extra_args', 'scp_extra_args', 'become', 'become_method', 'become_user', 'verbosity', 'check'
]
) # initialize needed objects
self.variable_manager = VariableManager()
self.options = Options(
listtags=False, listtasks=False, listhosts=False, syntax=False, connection='smart',
module_path='/usr/lib/python2.7/site-packages/ansible/modules', forks=100,
remote_user='root', private_key_file=None, ssh_common_args=None, ssh_extra_args=None,
sftp_extra_args=None, scp_extra_args=None, become=False, become_method=None, become_user='root',
verbosity=None, check=False
)
self.passwords = dict(vault_pass='secret')
self.loader = DataLoader() # create inventory and pass to var manager
self.hostsFile = NamedTemporaryFile(delete=False)
self.hostsFile.write(targetHost)
self.hostsFile.close()
self.inventory = Inventory(loader=self.loader, variable_manager=self.variable_manager, host_list=self.hostsFile.name)
self.variable_manager.set_inventory(self.inventory) def ansiblePlay(self, action):
# create play with tasks
args = "ls /"
play_source = dict(
name = "Ansible Play",
hosts = 'all',
gather_facts = 'no',
tasks = [
dict(action=dict(module='shell', args=args), register='shell_out'),
dict(action=dict(module='debug', args=dict(msg='{{shell_out.stdout}}')))
]
)
play = Play().load(play_source, variable_manager=self.variable_manager, loader=self.loader) # run it
tqm = None
try:
tqm = TaskQueueManager(
inventory=self.inventory,
variable_manager=self.variable_manager,
loader=self.loader,
options=self.options,
passwords=self.passwords,
stdout_callback='default',
)
result = tqm.run(play) finally: # print result
if tqm is not None:
tqm.cleanup()
os.remove(self.hostsFile.name)
self.inventory.clear_pattern_cache() return result写一个ansibleTask类，创建了上述的各类必要的配置信息对象，最后使用ansibleTask.ansiblePlay()函数执行。
inventory文件的动态生成
写上面的代码的过程中，碰到一个问题：inventory对象创建时需要一个实体的hosts文件，而文件需要动态生成。
生成的方法参考了这篇牛逼闪闪的文章。使用tempfile.NamedTemporaryFile这个方法来创建一个有名称的临时文件，可以选择关闭后删除或保留。上面的处理办法是：不删除，在执行完毕之后，通过os.remove(self.hostsFile.name)进行删除。
ps.经YiChenWang指出，inventory的创建参数host_list可以使列表。使用以下方式创建inventory也是可以的：
self.inventory = Inventory(loader=self.loader, variable_manager=self.variable_manager, host_list=['xx.xx.xx.xx', 'xx.xx.xx.xx'])
不过，源码中指出，采用list格式参数是无法加载inventory data的。如果需要加载，还是得使用临时文件的办法。
作者：茶客furu声
链接：https://www.jianshu.com/p/8558befb16c1
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