Linux中的docker報錯 Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

偶然一次在centos中安裝啟動docker時報錯：

Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

 

解決辦法如下：

1. Create the docker group.

   sudo groupadd docker

2. Add the user to the docker group.

   sudo usermod -aG docker $(whoami)

3. Log out and log back in to ensure docker runs with correct permissions.
4. Start docker.

   sudo service docker start