Docker.报错.Is the docker daemon running?

Is the docker daemon running?

[root@VM-0-12-centos ~]# docker search hello-world
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

启动docker

[root@iZ2zeca7jric8sx4f3n7spZ ~]# docker search redis
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
[root@iZ2zeca7jric8sx4f3n7spZ ~]# systemctl start docker

可以查找

[root@iZ2zeca7jric8sx4f3n7spZ ~]# docker search redis
NAME                             DESCRIPTION                                     STARS     OFFICIAL   AUTOMATED
redis                            Redis is an open source key-value store that…   8901      [OK]
bitnami/redis                    Bitnami Redis Docker Image                      169                  [OK]
sameersbn/redis                                                                  82                   [OK]