docker下配置mysql主从复制之slave无法复制master的问题解决

1.问题：从节点连接主节点错误，初步定位为网络原因

Last_IO_Error: error connecting to master ‘backup@192.168.1.150:3307’ - retry-time: 60 retries: 1

mysql> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Connecting to master
                  Master_Host: 192.168.1.150
                  Master_User: backup
                  Master_Port: 3307
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000001
          Read_Master_Log_Pos: 22499
               Relay_Log_File: 7f89b92077fc-relay-bin.000001
                Relay_Log_Pos: 4
        Relay_Master_Log_File: mysql-bin.000001
             Slave_IO_Running: Connecting
            Slave_SQL_Running: Yes
              Replicate_Do_DB: 
          Replicate_Ignore_DB: mysql,sys,information_schema,performance_schema
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 
      Replicate_Wild_Do_Table: 
  Replicate_Wild_Ignore_Table: 
                   Last_Errno: 0
                   Last_Error: 
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 4
              Relay_Log_Space: 154
              Until_Condition: None
               Until_Log_File: 
                Until_Log_Pos: 0
           Master_SSL_Allowed: No
           Master_SSL_CA_File: 
           Master_SSL_CA_Path: 
              Master_SSL_Cert: 
            Master_SSL_Cipher: 
               Master_SSL_Key: 
        Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 2003
                Last_IO_Error: error connecting to master 'backup@192.168.1.150:3307' - retry-time: 60  retries: 1
               Last_SQL_Errno: 0
               Last_SQL_Error: 
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 0
                  Master_UUID: 
             Master_Info_File: /var/lib/mysql/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           Master_Retry_Count: 86400
                  Master_Bind: 
      Last_IO_Error_Timestamp: 200104 07:26:47
     Last_SQL_Error_Timestamp: 
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
           Retrieved_Gtid_Set: 
            Executed_Gtid_Set: 
                Auto_Position: 0
         Replicate_Rewrite_DB: 
                 Channel_Name: 
           Master_TLS_Version: 
1 row in set (0.00 sec)

ERROR: 
No query specified

2.经历了曲折艰辛的弯路之后，找到了真正的问题所在：linux防火墙问题。之后关闭防火墙，主从同步正常。

[root@localhost data]# systemctl stop firewalld
[root@localhost data]# systemctl disable firewalld
Removed symlink /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.

3.直接关闭防火墙虽然两个docker容器可以互相访问了，但是当重启docker的容器时，会报iptables: No chain/target/match by that name.的错误。原因是因为systemctl start docker时是有防火墙的，在docker启动的状态下关闭防火墙会造成该问题。深度原因没有研究。

解决办法：在防火墙关闭的状态下重启docker。

[root@localhost data]# docker ps 
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                               NAMES
7f89b92077fc        mysql:5.7           "docker-entrypoint.s…"   2 hours ago         Up About an hour    33060/tcp, 0.0.0.0:3316->3306/tcp   mysql-slaver-01
054236fce86e        mysql:5.7           "docker-entrypoint.s…"   2 hours ago         Up About an hour    33060/tcp, 0.0.0.0:3307->3306/tcp   mysql-master
[root@localhost data]# docker restart 7f8
Error response from daemon: Cannot restart container 7f8: driver failed programming external connectivity on endpoint mysql-slaver-01 (c64f19fba0938f6016ff879d52476c0151e98429f1779a23b28b8bd94a28ef96):  (iptables failed: iptables --wait -t nat -A DOCKER -p tcp -d 0/0 --dport 3316 -j DNAT --to-destination 172.17.0.3:3306 ! -i docker0: iptables: No chain/target/match by that name.
 (exit status 1))
[root@localhost data]# SELINUX=disabled
[root@localhost data]# docker start 7f8
Error response from daemon: driver failed programming external connectivity on endpoint mysql-slaver-01 (76b66f4777354c50635ccc39db4d559d28278da055eabee6ce20e5083cac49ee):  (iptables failed: iptables --wait -t nat -A DOCKER -p tcp -d 0/0 --dport 3316 -j DNAT --to-destination 172.17.0.3:3306 ! -i docker0: iptables: No chain/target/match by that name.
 (exit status 1))
Error: failed to start containers: 7f8
[root@localhost data]# docker stop 054
054
[root@localhost data]# systemctl restart docker
[root@localhost data]# docker start 7f8
7f8
[root@localhost data]# docker start 054
054
[root@localhost data]#