解决 saltstack 的 authenticate 问题

master 重启后，test.ping 测试不通，报错如下：

# salt "*" test.ping
Salt request timed out. The master is not responding. 
You may need to run your command with `--async` in order to bypass the congested event bus. 
With `--async`, the CLI tool will print the job id (jid) and exit immediately without listening for responses. 
You can then use `salt-run jobs.lookup_jid` to look up the results of the job in the job cache later.

经查是防火墙原因，依次执行以下命令：

# iptables -A INPUT -p tcp --dport 4505 -j ACCEPT
# iptables -A INPUT -p tcp --dport 4506 -j ACCEPT

查看 iptables 发现添加成功：

# iptables -L -n
Chain INPUT (policy ACCEPT)
target     prot opt source               destination
ACCEPT     udp  --  0.0.0.0/0            0.0.0.0/0            udp dpt:53
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:53
ACCEPT     udp  --  0.0.0.0/0            0.0.0.0/0            udp dpt:67
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:67
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:4505    // 添加成功
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:4506    // 添加成功

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination
ACCEPT     all  --  0.0.0.0/0            192.168.122.0/24     ctstate RELATED,ESTABLISHED
ACCEPT     all  --  192.168.122.0/24     0.0.0.0/0
ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0
REJECT     all  --  0.0.0.0/0            0.0.0.0/0            reject-with icmp-port-unreachable
REJECT     all  --  0.0.0.0/0            0.0.0.0/0            reject-with icmp-port-unreachable
DOCKER-ISOLATION  all  --  0.0.0.0/0            0.0.0.0/0
DOCKER     all  --  0.0.0.0/0            0.0.0.0/0
ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0            ctstate RELATED,ESTABLISHED
ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0
ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination
ACCEPT     udp  --  0.0.0.0/0            0.0.0.0/0            udp dpt:68

Chain DOCKER (1 references)
target     prot opt source               destination

Chain DOCKER-ISOLATION (1 references)
target     prot opt source               destination
RETURN     all  --  0.0.0.0/0            0.0.0.0/0

等待片刻（salt 的反应有时真的挺慢的...），就可以恢复了：

# salt "*" test.ping
node-5:
    True
node-4:
    True

后续：
经过以上的处理，test.ping 依旧有时正常有时不正常...
再查，通过修改 master 文件，增大了 worker_thread 的数量，目前看起来总能返回正常结果了...