背景：centos7

1. vi /usr/lib/systemd/system/docker.service 修改 [Service]的ExecStart，ExecStart= 一定要加

[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker
ExecStart=
ExecStart=/usr/bin/dockerd -H tcp://0.0.0.0:2375 -H unix://var/run/docker.sock

2. 刷新配置文件，重启docker

systemctl daemon-reload
systemctl restart docker

3. 查看docker进程是否监听

[root@localhost ~]# netstat -ano | grep 2375
tcp6       0      0 :::2375                 :::*                    LISTEN      off (0.00/0/0)

4.查看系统网络端口2375是否被docker所监听

[root@localhost ~]# netstat -tulp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 0.0.0.0:ssh             0.0.0.0:*               LISTEN      3124/sshd           
tcp        0      0 localhost:smtp          0.0.0.0:*               LISTEN      3379/master         
tcp6       0      0 [::]:2375               [::]:*                  LISTEN      13964/dockerd       
      

5.添加防火墙2375/tcp ，并重载防火墙

[root@localhost ~]#  firewall-cmd --zone=public --add-port=2375/tcp --permanent
success
[root@localhost ~]# firewall-cmd --reload
success

6. 使用idea测试连接docker， 看到Connection successful说明连接成功

启动该Docker就可以运行容器了

Time the study pain is temporary, has not learned the pain is life-long.