Docker官方hub上拉取的镜像，很多时候并不能满足自己公司项目所要使用的环境，需要基于官方镜像进行定制化。

拉取官方镜像

此次测试定制基础镜像使用的是CentOS官方基础镜像,TAG为：centos:centos7.9.2009

docker pull centos:centos7.9.2009

将本地镜像推送到本地镜像仓库（可不做）

推送本地搭建的harbor镜像仓库的目的主要是担心hub.docker.com的访问稳定性。

[root@harbor lab]# docker tag centos:centos7.9.2009 10.100.202.211/centos/centos:centos7.9.2009
[root@harbor lab]# docker push 10.100.202.211/centos/centos:centos7.9.2009
The push refers to repository [10.100.202.211/centos/centos]
174f56854903: Pushed 
centos7.9.2009: digest: sha256:dead07b4d8ed7e29e98de0f4504d87e8880d4347859d839686a31da35a3b532f size: 529

启动容器

启动容器的目的在于接下来要执行的命令需要在容器中验证命令的有效性，以便通过dockerfile构建定制化容器镜像时可以顺利完成。

[root@harbor lab]# docker run -d -it --name centos-ini eeb6ee3f44bd 
440cb009c419ffc72dd242afd650a1cbc244b345e8aef962167f88909f4389d7

修改容器默认软件源为阿里云

连接到容器中，执行以下命令修改软件源：

# 连接到刚刚启动的容器
docker attach centos-ini
# 修改软件源为阿里云
[root@6edc8ad63088 yum.repos.d]# curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  2523  100  2523    0     0    935      0  0:00:02  0:00:02 --:--:--   935
# 因为服务器并非阿里云ECS实例，所以需要删除关于aliyuncs.com相关的域名地址
[root@6edc8ad63088 /]# sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo

通过dockerfile构建定制化容器镜像

# 创建目录
mkdir centos-pdc && cd centos-pdc
[root@harbor centos-pdc]# cat dockerfile 
FROM 10.100.202.211/centos/centos:centos7.9.2009
RUN curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo && sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo
CMD "/bin/bash"

# 基于dockerfile构建定制化容器镜像
[root@harbor centos-pdc]# docker build -t centos-pdc:v1.0 .
Sending build context to Docker daemon  2.048kB
Step 1/3 : FROM 10.100.202.211/centos/centos:centos7.9.2009
 ---> eeb6ee3f44bd
Step 2/3 : RUN curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo && sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo
 ---> Running in 8598ee505816
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed                                          
100  2523  100  2523    0     0   1254      0  0:00:02  0:00:02 --:--:--  1254                                         
Removing intermediate container 8598ee505816                                                                           
 ---> 3daf441e0efc
Step 3/3 : CMD "/bin/bash"
 ---> Running in 81547977b798
Removing intermediate container 81547977b798
 ---> a298bd8361a2
Successfully built a298bd8361a2
Successfully tagged centos-pdc:v1.0

[root@harbor centos-pdc]# docker images
REPOSITORY                                          TAG              IMAGE ID       CREATED         SIZE
centos-pdc                                          v1.0             a298bd8361a2   4 minutes ago   204MB

推送构建的镜像到harbor仓库

上面根据dockerfile构建出的镜像，可以为其打tag后，push到私有化镜像仓库harbor存储，以便其他人直接使用该镜像。

[root@harbor centos-pdc]# docker tag centos-pdc:v1.0 10.100.202.211/centos/centos-pdc:20220718
[root@harbor centos-pdc]# docker push 10.100.202.211/centos/centos-pdc:20220718
The push refers to repository [10.100.202.211/centos/centos-pdc]
6ba235257a6f: Pushed 
174f56854903: Mounted from centos/centos 
20220718: digest: sha256:091768246ae8da68092b36a6a69f6a096c6e56b85b22e51c4acf416c7b274358 size: 737