docker修改镜像名称

[root@localhost ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
pujh/centos         tomcat-centos       70ff7873d7cd        About an hour ago    MB
docker.io/centos    latest              9f38484d220f         days ago          MB
[root@localhost ~]# docker tag 70ff7873d7cd my_centos:tomcat-centos
[root@localhost ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
my_centos           tomcat-centos       70ff7873d7cd        About an hour ago   612 MB
pujh/centos         tomcat-centos       70ff7873d7cd        About an hour ago    MB
docker.io/centos    latest              9f38484d220f         days ago          MB

[root@localhost ~]# docker rmi 70ff7873d7cd
Error response from daemon: conflict: unable to delete 70ff7873d7cd (cannot be forced) - image is being used by running container 70859e710147
[root@localhost ~]# docker ps -a
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                      PORTS                    NAMES
70859e710147        70ff                "/bin/sh -c '/root..."   About an hour ago   Up About an hour            0.0.0.0:->/tcp   dazzling_hopper
[root@localhost ~]# docker stop 70859e710147 

[root@localhost ~]# docker rm 70859e710147 

[root@localhost ~]# docker rmi 70ff7873d7cd

[root@localhost ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
my_centos           tomcat-centos       70ff7873d7cd        About an hour ago   612 MB
docker.io/centos    latest              9f38484d220f        11 days ago         202 MB