DevOps干货：Saltstack Syndic（minion谷）

#自动化运维# #干货#

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简介

syndic是master和minion之间的一个代理层, 用来转发来自master的指令给minion. syndic可以扩展整个saltstack的架构规模.

组成

一个syndic node包含2个组件

a salt-syndic daemon
a salt-master daemon

配置

CONFIGURING THE SYNDIC

The id option is used by the salt-syndic daemon to identify with the Master node and if unset will default to the hostname or IP address of the Syndic just as with a Minion.

CONFIGURING THE SYNDIC WITH MULTIMASTER

If the master_id value is set in the master config on the higher level masters, job results are returned to the master that originated the request in a best effort fashion. Events/jobs without a master_id are returned to any available master.

命令和结果的传递Permalink

详情参考 https://docs.saltstack.com/en/latest/topics/topology/syndic.html#topology

SYNDIC WAITPermalink

syndic_wait: master等待syndic返回结果的时间, 默认是5s. 该选项在发送指令的master上/etc/salt/master文件里配置.

Debug执行日志Permalink

发送一条指令

[root@master vagrant]# salt 'client.jacky.com' cmd.run 'uptime' client.jacky.com: 11:43:21 up 2:56, 1 user, load average: 0.00, 0.00, 0.00

Master

Syndic

Minion

源码分析Permalink

salt代码版本是2015.8.

Syndic的源码在/salt/salt/minion.py中class Syndic. 核心主逻辑在tune_in方法.

. # Syndic Tune In def tune_in(self, start=True): ''' Lock onto the publisher. This is the main event loop for the syndic ''' signal.signal(signal.SIGTERM, self.clean_die) log.debug('Syndic {0!r} trying to tune in'.format(self.opts['id'])) if start: self.sync_connect_master() # 以'sub'的角色连接到master的pub端口. # Instantiate the local client # 实例化LocalClient对象 self.local = salt.client.get_local_client(self.opts['_minion_conf_file']) self.local.event.subscribe('') self.local.opts['interface'] = self._syndic_interface # add handler to subscriber self.pub_channel.on_recv(self._process_cmd_socket) # 在连接上添加回调函数, 只要接到新命令就解密, 并且转发给local的master. # `_process_cmd_socket`调用了`_handle_decoded_payload`, 又调用了`self.syndic_cmd(data)` # 在`syndic_cmd`方法里调用了`self.local.pub`将从上级Master接收的指令通过LocalClient转发给本地 # 的Master. # register the event sub to the poller self._reset_event_aggregation() self.local_event_stream = zmq.eventloop.zmqstream.ZMQStream(self.local.event.sub, io_loop=self.io_loop) self.local_event_stream.on_recv(self._process_event) # 监听本地的event pub接口获取minion的命令执行结果 # forward events every syndic_event_forward_timeout self.forward_events = tornado.ioloop.PeriodicCallback(self._forward_events, # 通过`_forward_events`方法调用`self._return_pub`将结果转发回上级Master. self.opts['syndic_event_forward_timeout'] * 1000, io_loop=self.io_loop) self.forward_events.start() # Send an event to the master that the minion is live self._fire_master_syndic_start() # Make sure to gracefully handle SIGUSR1 enable_sigusr1_handler() if start: self.io_loop.start()任务异步Permalink

提交异步任务: salt 'client.jacky.com' cmd.run 'uptime' --async --show-jid

执行结果异步化接收的方法有如下几种, 参考这里