Executes the Docker PS command, appearing "Cannot connect to the" Docker daemon at Unix:///var/run/docker.sock. ... "Question

Execute Docker PS command, appear

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

Error

It is now determined that the Docker itself is installed properly.

The problem is because the Docker service did not start, so the Docker process could not be found under the corresponding/var/run/path.

Execute service Docker start command, start Docker services, return

Docker start/running, Process 2662

At this point the process starts successfully, then executes Docker PS, the problem is solved