docker研究-4 docker镜像制作

　　这次实验以centos镜像为基础镜像进行相关docker镜像制作。

1.　下载centos镜像　　　　

[root@localhost ~]# docker pull centos
Using default tag: latest
Trying to pull repository docker.io/library/centos ...
latest: Pulling from docker.io/library/centos
729ec3a6ada3: Pull complete
Digest: sha256:f94c1d992c193b3dc09e297ffd54d8a4f1dc946c37cbeceb26d35ce1647f88d9
Status: Downloaded newer image for docker.io/centos:latest

 　　例子：制作nginx镜像