从零制作一个docker的镜像
近期docker的镜像仓库不好用了，很多国内的源也无法使用了，所有今天给大家分享一下怎么从零制作一个CentOS镜像。
准备CentOS7最小环境
mkdir /centos7.9-root# 在该目录准备centos的最小环境
sudo yum --installroot=/centos7.9-root --releasever=7 install -y centos-release
sudo yum --installroot=/centos7.9-root --releasever=7 groupinstall -y "Core"构建镜像
mkdir centos7
cd centos7
mv /centos7.9-root ./# 编写Dockerfile文件
# 这是Docker提供的一个相当于是空白的镜像，直接就可以用的不用下载
cat > Dockerfile << EOF
FROM scratch
ADD centos7.9-root /
CMD ["/bin/bash"]
EOF# 构建镜像
docker build -t centos:7.9 .
[root@bogon centos7]# docker build -t centos:7.9 .
[+] Building 33.3s (5/5) FINISHED docker:default=> [internal] load build definition from Dockerfile 0.0s=> => transferring dockerfile: 89B 0.0s=> [internal] load .dockerignore 0.0s=> => transferring context: 2B 0.0s=> [internal] load build context 14.5s=> => transferring context: 1.37GB 14.5s=> [1/1] ADD centos7.9-root / 7.7s=> exporting to image 10.9s=> => exporting layers 10.9s=> => writing image sha256:359d4c8ae6f4f9d700d847f38066f52344c628789d868e196 0.0s=> => naming to docker.io/library/centos:7.9 0.0s
测试
[root@bogon ~]# docker run -it --rm centos:7.9 bash
[root@c74f76deee3d /]#