剛安裝完docker後
執行docker pull ubuntu 時報錯：
[root@comk ~]# docker pull ubuntu
Post http:///var/run/docker.sock/v1.19/p_w_picpaths/create?fromImage=ubuntu%3Alatest:
dial unix /var/run/docker.sock: no such file or directory. Are you trying to con
nect to a TLS-enabled daemon without TLS?
解決：service docker start