import json
from collections import namedtuple
from ansible.parsing.dataloader import DataLoader
from ansible.vars import VariableManager
from ansible.inventory import Inventory
from ansible.playbook.play import Play
from ansible.executor.task_queue_manager import TaskQueueManager
from ansible.executor.task_result import TaskResult
from ansible.plugins.callback import CallbackBase


# 自定义 callback，即在运行 api 后调用本类中的 v2_runner_on_ok()，在这里会输出 host 和 result 格式
class ResultCallback(CallbackBase):
    """A sample callback plugin used for performing an action as results come in

    If you want to collect all results into a single object for processing at
    the end of the execution, look into utilizing the ``json`` callback plugin
    or writing your own custom callback plugin
    """
    def v2_runner_on_ok(self, result, **kwargs):
        """Print a json representation of the result

        This method could store the result in an instance attribute for retrieval later
        """
        # result 包含‘_check_key‘, ‘_host‘, ‘_result‘, ‘_task‘, ‘is_changed‘, ‘is_failed‘, ‘is_skipped‘, ‘is_unreachable‘
        host = result._host
        print json.dumps({host.name: result._result}, indent=4)
    
    """
    def v2_on_any(self, *args, **kwargs):
        if isinstance(args[0], TaskResult):
            print json.dumps({args[0]._host.name: args[0]._result}, indent=4)
    """
            
Options = namedtuple(‘Options‘, [‘connection‘, ‘module_path‘, ‘forks‘, ‘become‘, ‘become_method‘, ‘become_user‘, ‘check‘])
# initialize needed objects
variable_manager = VariableManager()
loader = DataLoader()
options = Options(connection=‘smart‘, module_path=None, forks=100, become=None, become_method=None, become_user=None, check=False)
passwords = dict(conn_pass=‘mypassword‘)  # 目前只发现有两个key，conn_pass, become_pass

# Instantiate our ResultCallback for handling results as they come in
results_callback = ResultCallback()

# create inventory and pass to var manager
inventory = Inventory(loader=loader, variable_manager=variable_manager, host_list=‘hosts‘)  # hosts文件，也可以是 ip列表
variable_manager.set_inventory(inventory)

# create play with tasks
play_source =  dict(
        name = "Ansible Play",
        hosts = ‘web‘,   # 对应 playbook 入口yaml文件的 hosts变量，也可以是 ip
        gather_facts = ‘no‘,
        tasks = [
            dict(action=dict(module=‘shell‘, args=‘ifconfig‘), register=‘shell_out‘),
            #dict(action=dict(module=‘debug‘, args=dict(msg=‘{{shell_out.stdout}}‘)))
         ]
    )
play = Play().load(play_source, variable_manager=variable_manager, loader=loader)

# actually run it
# TaskQueueManager 是创建进程池，负责输出结果和多进程间数据结构或者队列的共享协作
tqm = None
try:
    tqm = TaskQueueManager(
              inventory=inventory,
              variable_manager=variable_manager,
              loader=loader,
              options=options,
              passwords=passwords,
              stdout_callback=results_callback,  # Use our custom callback instead of the ``default`` callback plugin
              # 如果注释掉 callback 则会调用原生的 DEFAULT_STDOUT_CALLBACK，输出 task result的output，同 ansible-playbook debug
          )
    result = tqm.run(play)
    print result  # 返回码，只要有一个 host 出错就会返回 非0 数字
finally:
    if tqm is not None:
        tqm.cleanup()

v2_runner_on_failed(self, result, ignore_errors=False)
v2_runner_on_ok(self, result)
v2_runner_on_skipped(self, result)
v2_runner_on_unreachable(self, result)
v2_runner_on_no_hosts(self, task)