centos 7 使用yum 安装docker 报错

错误:

One of the configured repositories failed (Docker CE Stable - x86\_64), and yum doesn't have enough cached data to continue. At this point the only safe thing yum can do is fail. There are a few ways to work "fix" this: 
1. Contact the upstream for the repository and get them to fix the problem.
2. Reconfigure the baseurl/etc. for the repository, to point to a working upstream. This is most often useful if you are using a newer distribution release than is supported by the repository (and the packages for the previous distribution release still work). 
3. Run the command with the repository temporarily disabled yum --disablerepo=docker-ce-stable ... 
4. Disable the repository permanently, so yum won't use it by default. Yum will then just ignore the repository until you permanently enable it again or use --enablerepo for temporary usage: yum-config-manager --disable docker-ce-stable or subscription-manager repos --disable=docker-ce-stable 
5. Configure the failing repository to be skipped, if it is unavailable. Note that yum will try to contact the repo. when it runs most commands, so will have to try and fail each time (and thus. yum will be be much slower). If it is a very temporary problem though, this is often a nice compromise: yum-config-manager --save --setopt=docker-ce-stable.skip\_if\_unavailable=true failure: repodata/repomd.xml from docker-ce-stable: \[Errno 256\] No more mirrors to try. https://download-stage.docker.com/linux/centos/7/x86\_64/stable/repodata/repomd.xml: \[Errno 14\] curl#7 - "Failed to connect to 2600:9000:2012:6c00:4:1d08:9b80:93a1: 网络不可达"

错误原因:

docker-ce.repo中配置的镜像站无法找到对应的镜像

解决办法:

将docker-ce.repo(linux查找方法: find -name docker-ce.repo)
中的镜像地址替换为中科院提供的镜像地址

[docker-ce-stable\] name=Docker CE Stable - $basearch baseurl= https://mirrors.ustc.edu.cn/docker-ce/linux/centos/7/$basearch/stable enabled=1 gpgcheck=1 gpgkey=https://mirrors.ustc.edu.cn/docker-ce/linux/centos/gpg