执行docker pull redis时出错
Using default tag: latest
Warning: failed to get default registry endpoint from daemon (Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?). Using system default: https://index.docker.io/v1/
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?原来是自己没启动docker
解决方式：
service docker start
现在pull是成功的
Using default tag: latest
latest: Pulling from library/redis
27833a3ba0a5: Downloading 3.189MB/22.5MB
cde8019a4b43: Download complete
97a473b37fb2: Downloading 326.4kB/941.4kB
c6fe0dfbb7e3: Downloading 4.189MB/11.78MB
39c8f5ba1240: Waiting
cfbdd870cf75: Waiting