在1中我们已经完成docker的安装，接下来安装镜像。我们安装一个centos7的镜像。
首先我们可以将docker设置成开机自启动：
[root@localhost ~]# systemctl enable docker.service Created symlink /etc/systemd/system/multi-user.target.wants/docker.service → /usr/lib/systemd/system/docker.service. [root@localhost ~]# systemctl enable containerd.service Created symlink /etc/systemd/system/multi-user.target.wants/containerd.service → /usr/lib/systemd/system/containerd.service.
然后开始下载镜像，我这里下载一个centos7的镜像文件，如下：
[root@localhost ~]# docker pull centos:centos7
centos7: Pulling from library/centos
2d473b07cdd5: Downloading [===> ] 4.823MB/76.1MB
下载之前也可以搜索一下看哪个镜像更合适，命令如下：
[root@localhost ~]# docker search centos
NAME DESCRIPTION STARS OFFICIAL AUTOMATED
centos The official build of CentOS. 6484 [OK]
ansible/centos7-ansible Ansible on Centos7 133 [OK]
consol/centos-xfce-vnc Centos container with "headless" VNC session… 127 [OK]
jdeathe/centos-ssh OpenSSH / Supervisor / EPEL/IUS/SCL Repos - … 117 [OK]
centos/systemd systemd enabled base container. 97 [OK]
centos/mysql-57-centos7 MySQL 5.7 SQL database server 87
imagine10255/centos6-lnmp-php56 centos6-lnmp-php56 58 [OK]
tutum/centos Simple CentOS docker image with SSH access 47
kinogmt/centos-ssh CentOS with SSH 29 [OK]
pivotaldata/centos-gpdb-dev CentOS image for GPDB development. Tag names… 13
guyton/centos6 From official centos6 container with full up… 10 [OK]
nathonfowlie/centos-jre Latest CentOS image with the JRE pre-install… 8 [OK]
centos/tools Docker image that has systems administration… 7 [OK]
drecom/centos-ruby centos ruby 6 [OK]
pivotaldata/centos Base centos, freshened up a little with a Do… 5
pivotaldata/centos-gcc-toolchain CentOS with a toolchain, but unaffiliated wi… 3
darksheer/centos Base Centos Image -- Updated hourly 3 [OK]
由于dockerhub默认使用的是国外源，下载速度较慢，可以修改为国内源，方式如下，修改或者创建/etc/docker/daemon.json文件，添加上国内源即可。
[root@localhost ~]# vi /etc/docker/daemon.json
{
"registry-mirrors": ["http://hub-mirror.c.163.com"]
}
目前常用的国内源有：
Docker 官方中国区 https://registry.docker-cn.com 网易 http://hub-mirror.c.163.com 中国科技大学 https://docker.mirrors.ustc.edu.cn 阿里云 https://pee6w651.mirror.aliyuncs.com
然后下载完成，可以看到如下：
[root@localhost ~]# docker pull centos:centos7 centos7: Pulling from library/centos 2d473b07cdd5: Pull complete Digest: sha256:0f4ec88e21daf75124b8a9e5ca03c37a5e937e0e108a255d890492430789b60e Status: Downloaded newer image for centos:centos7 docker.io/library/centos:centos7 [root@localhost ~]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE hello-world latest d1165f221234 3 weeks ago 13.3kB centos centos7 8652b9f0cb4c 4 months ago 204MB
接下来我们可以运行这个容器：
[root@localhost ~]# docker run -it centos:centos7 /bin/bash
[root@c1c3d9b90171 /]# ls
bin dev etc home lib lib64 lost+found media mnt opt proc root run sbin srv sys tmp usr var
参数说明：cc9cf968068e
-i: 交互式操作。
-t: 终端。
centos:centos7: 这是指用 centos版本镜像为基础来启动容器。centos7表示用版本7的镜像运行，若不加centos7则默认使用centos:latest运行。
/bin/bash：放在镜像名后的是命令，这里我们希望有个交互式 Shell，因此用的是 /bin/bash。
删除镜像：
[root@localhost ~]# docker rmi hello-world
Error response from daemon: conflict: unable to remove repository reference "hello-world" (must force) - container cc9cf968068e is using its referenced image d1165f221234
我们看到在删除hello-world的时候出现报错，说容器cc9cf968068e正在使用该镜像，所以在删除镜像之前需要删除该镜像创建的容器，然后再删除镜像即可。
[root@localhost ~]# docker rm cc9cf968068e cc9cf968068e [root@localhost ~]# docker rmi hello-world Untagged: hello-world:latest Untagged: hello-world@sha256:308866a43596e83578c7dfa15e27a73011bdd402185a84c5cd7f32a88b501a24 Deleted: sha256:d1165f2212346b2bab48cb01c1e39ee8ad1be46b87873d9ca7a4e434980a7726 Deleted: sha256:f22b99068db93900abe17f7f5e09ec775c2826ecfe9db961fea68293744144bd
若是要查看所有容器的ID或者所有镜像的ID，并针对镜像ID做操作可以使用如下方式
[root@localhost ~]# docker images -q #查看所有镜像ID d1165f221234 300e315adb2f 8652b9f0cb4c [root@localhost ~]# docker ps -aq #查看所有容器ID e63520d23e40 c1c3d9b90171 301f9596af4d c6763b64f608 8ce62505290a deca3b2f0da9 [root@localhost ~]# docker stop $(docker ps -aq) #停止所有容器 e63520d23e40 c1c3d9b90171 301f9596af4d c6763b64f608 8ce62505290a deca3b2f0da9 [root@localhost ~]# docker rm $(docker ps -aq) #删除所有容器 e63520d23e40 c1c3d9b90171 301f9596af4d c6763b64f608 8ce62505290a deca3b2f0da9 [root@localhost ~]# docker rmi $(docker images -q) #删除全部镜像 d1165f221234 300e315adb2f 8652b9f0cb4c