Salt Master报错:Minion did not return. [No response]

在salt master端执行salt ‘*’ test.ping时，某一节点出现如下报错：
Minion did not return. [No response]

登陆到这一节点查看minion的日志，发现如下的问题：

 $ tail -f /var/log/salt/minion
 The master may need to be updated if it is a version of Salt lower than 2015.5., or
 If you are confident that you are connecting to a valid Salt Master, then remove the master public key and restart the Salt Minion.
 The master public key can be found at:
 /etc/salt/pki/minion/minion_master.pub
 -- ::, [salt.crypt                               ][ERROR   ][] The Salt Master has cached the public key for this node, this salt minion will wait for  seconds before attempting to re-authenticate
 -- ::, [salt.crypt                               ][ERROR   ][] The Salt Master has cached the public key for this node, this salt minion will wait for  seconds before attempting to re-authenticate
 -- ::, [salt.crypt                               ][ERROR   ][] The Salt Master has cached the public key for this node, this salt minion will wait for  seconds before attempting to re-authenticate
  

minion大概的意思就是，minion端拿到的key与master端的不符，验证无法通过。
解决方法是删除minion端的key，再重新与master进行连接和认证。

 $ cat pki/minion/minion_master.pub
 -----BEGIN PUBLIC KEY-----
 MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAtzq0AjuyQsVEgsx692GN
 ... ...
 7fbuudp4yu5vcYcqksKIFcm0J3E+OR+rx/NUIHt0ZL8HLxcSn4Si/S6dVp/vE7Oc
 swIDAQAB
 -----END PUBLIC KEY-----
 [root@localhost salt]# rm -fr pki/minion/minion_master.pub

 [root@localhost salt]# service salt-minion restart
 Stopping salt-minion daemon:                               [  OK  ]
 Starting salt-minion daemon:                               [  OK  ]
13 salt-key -A　　　　　　##重新加载key

至此，master与minion端的通信正常。