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

[root@ls-bptysztw ~]# docker ps
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
[root@ls-bptysztw ~]# docker-compose version
docker-compose version 1.29.1, build c34c88b2
docker-py version: 5.0.0
CPython version: 3.7.10
OpenSSL version: OpenSSL 1.1.0l  10 Sep 2019

启动docker即可

systemctl start docker