Cannot connect to the Docker daemon but hello world from docker works

Question

I've stucked on this for days, I've checked the docker is running by docker run hello-world. But why still see the error?

Answer 1

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

above error messages is related to docker service. Service might be not running.

check first systemctl status docker. if status is stop, please run following commands.

systemctl start docker

systemctl enable docker

And then, please check again .