【Patroni源码阅读】pg初始化用户配置

post_bootstrap.py

class Ha(object):
    def post_bootstrap(self):
        # 当PG启动后，master节点执行用户名初始化，以及自定义脚本等工作
        with self._async_response:
            result = self._async_response.result
        # bootstrap has failed if postgres is not running
        if not self.state_handler.is_running() or result is False:
            # cancel_initialization() 函数会进行以下操作：
            # - 删除dcs上的initialize 信息
            # - 强制停止pg
            # - 清除数据目录
            self.cancel_initialization()

        # pg正在运行
        if result is None:
            # pg还处在recovery状态
            if not self.state_handler.is_leader():
                return 'waiting for end of recovery after bootstrap'
            # 作为master启动
            self.state_handler.set_role('master')
            # 异步线程启动pg
            # 此处self.state_handler.bootstrap.post_bootstrap 接受两个参数，第一个是启动配置self.patroni.config['bootstrap']，第二个用户接受启动的返回结果
            ret = self._async_executor.try_run_async('post_bootstrap', self.state_handler.bootstrap.post_bootstrap,
                                                     args=(self.patroni.config['bootstrap'], self._async_response))
            return ret or 'running post_bootstrap'

        # 这里清空state_handler.bootstrapping参数，下一个loop不会在进入
        self.state_handler.bootstrapping = False
        if not self.watchdog.activate():
            logger.error('Cancelling bootstrap because watchdog activation failed')
            self.cancel_initialization()
        # 不知道干啥的？
        self._rewind.ensure_checkpoint_after_promote(self.wakeup)
        #
        self.dcs.initialize(create_new=(self.cluster.initialize is None), sysid=self.state_handler.sysid)
        self.dcs.set_config_value(json.dumps(self.patroni.config.dynamic_configuration, separators=(',', ':')))
        self.dcs.take_leader()
        self.set_is_leader(True)
        self.state_handler.call_nowait(ACTION_ON_START)
        self.load_cluster_from_dcs()

        return 'initialized a new cluster'