docker info命令
輸出顯示：
Server: ERROR: Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
本次解決問題的資料：
關於Docker啟動報錯：docker.socket: Failed to listen on sockets: Address already in use
https://www.cnblogs.com/Conwie/p/14462232.html
不能解決的網上資料：
網上查了一堆資料，沒找到解決方法
編輯 vim /etc/docker/daemon.json （解決不了） https://blog.csdn.net/sdrfengmi/article/details/87929593 寫在docker后重新安裝 （不考慮） 添加docker用戶組 （已經有用戶組了） https://www.dazhuanlan.com/2019/12/31/5e0b0af5a3191/ 還有修改 vi /etc/sysconfig/selinux文件信息的（不考慮） https://blog.csdn.net/qq_40996741/article/details/98473966
然后想着先停掉docker服務。
停服務時候報錯了
systemctl stop docker.service
Warning: Stopping docker.service, but it can still be activated by:
docker.socket
docker服務還是存活了，根據docker.socket文件。
接着啟動docker服務
systemctl start docker.service
錯誤信息如下：
A dependency job for docker.service failed. See 'journalctl -xe' for details
systemctl status docker.service
查看服務狀態：
● docker.service - Docker Application Container Engine Loaded: loaded (/usr/lib/systemd/system/docker.service; enabled; vendor preset: disabled) Active: inactive (dead) since Tue 2021-06-08 09:53:44 CST; 10min ago Docs: https://docs.docker.com Main PID: 4695 (code=exited, status=0/SUCCESS) Jun 08 09:53:42 VM-0-13-centos dockerd[4695]: time="2021-06-08T09:53:42.8864784..." Jun 08 09:53:42 VM-0-13-centos dockerd[4695]: time="2021-06-08T09:53:42.9251783..." Jun 08 09:53:44 VM-0-13-centos dockerd[4695]: time="2021-06-08T09:53:44.9135121..." Jun 08 09:53:44 VM-0-13-centos systemd[1]: Stopped Docker Application Container.... Jun 08 09:57:52 VM-0-13-centos systemd[1]: Dependency failed for Docker Applica.... Jun 08 09:57:52 VM-0-13-centos systemd[1]: Job docker.service/start failed with.... Jun 08 10:01:29 VM-0-13-centos systemd[1]: Dependency failed for Docker Applica.... Jun 08 10:01:29 VM-0-13-centos systemd[1]: Job docker.service/start failed with.... Jun 08 10:03:09 VM-0-13-centos systemd[1]: Dependency failed for Docker Applica.... Jun 08 10:03:09 VM-0-13-centos systemd[1]: Job docker.service/start failed with.... Hint: Some lines were ellipsized, use -l to show in full
看不出來錯誤信息
然后使用 journalctl -xe 命令查看系統日志信息
主要就是紅框里
Jun 08 10:08:41 VM-0-13-centos systemd[1]: docker.socket failed to listen on sockets: Address already in use
Jun 08 10:08:41 VM-0-13-centos systemd[1]: Failed to listen on Docker Socket for the API.
錯誤提示：監聽socket時，發現地址已經被使用。
然后去查看 /var/run/ 目錄的docker文件
發現docker.sock 文件變成的目錄 docker.dock/
刪除這個目錄就可以解決問題
rm -rf /var/run/docker.sock/
然后能正常啟動docker服務
systemctl restart docker
