国外镜像太慢了。可以找一个国内的。比如：https://hub.daocloud.io/ 【其它的应用安装我都是用的 阿里 镜像：https://cr.console.aliyun.com/】

[root@localhost ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
tomcat9             latest              f1338fd7a813        2 days ago          712MB
mysql               5.7                 84164b03fa2e        7 days ago          456MB
centos              latest              470671670cac        7 weeks ago         237MB
#daocloud.io/library/redis:3.2.9 后面不指定版本号，将会拉取最新版本，imags tag 里面会显示  latest
[root@localhost ~]# docker pull daocloud.io/library/redis:3.2.9
3.2.9: Pulling from library/redis
552d35eef8d3: Pull complete 
1456a69aa136: Pull complete 
1f49a48e1dbe: Pull complete 
1875385cdd4d: Pull complete 
f069bec08661: Pull complete 
ba86db61d6ab: Pull complete 
Digest: sha256:1abd60075275d7d821a885a4c6d835d7ff1c7a08854ec9a3a277d2847900d863
Status: Downloaded newer image for daocloud.io/library/redis:3.2.9
[root@localhost ~]# docker images
REPOSITORY                  TAG                 IMAGE ID            CREATED             SIZE
tomcat9                     latest              f1338fd7a813        2 days ago          712MB
mysql                       5.7                 84164b03fa2e        7 days ago          456MB
centos                      latest              470671670cac        7 weeks ago         237MB
daocloud.io/library/redis   3.2.9               3459037fcc3a        2 years ago         98.9MB
[root@localhost ~]# docker run -d -p 6379:6379 --name redis3.2.9 daocloud.io/library/redis:3.2.9 --requirepass "123456"
542603098bbfd0686ffbf777d77485b5e1ae1ee89ed95774d1d800a7258784a1
#-d 守护进程运行（后台运行）
# -p 端口映射
#--name 容器名称
#daocloud.io/library/redis:3.2.9 容器名:TAG ,见 docker images 命令,如果pull有版本号，这边不指定版本号，将会重新pull一次最新版本，并启动
#--requirepass 设置密码
[root@localhost ~]#