CentOS7 docker.repo 用阿里云Docker Yum源

yum安装软件的时候经常出现找不到镜像的情况

https://download.docker.com/linux/centos/7/x86_64/stable/repodata/repomd.xml: [Errno 12] Timeout on 

解决方法：更新/etc/yum.repos.d目录下的docker.repo文件内容，使用阿里的镜像源

[docker-ce-stable]
name=Docker CE Stable - $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/$basearch/stable
enabled=
gpgcheck=
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-stable-debuginfo]
name=Docker CE Stable - Debuginfo $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/debug-$basearch/stable
enabled=
gpgcheck=
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-stable-source]
name=Docker CE Stable - Sources
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/source/stable
enabled=
gpgcheck=
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-edge]
name=Docker CE Edge - $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/$basearch/edge
enabled=
gpgcheck=
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-edge-debuginfo]
name=Docker CE Edge - Debuginfo $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/debug-$basearch/edge
enabled=
gpgcheck=
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-edge-source]
name=Docker CE Edge - Sources
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/source/edge
enabled=
gpgcheck=
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-test]
name=Docker CE Test - $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/$basearch/test
enabled=
gpgcheck=
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-test-debuginfo]
name=Docker CE Test - Debuginfo $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/debug-$basearch/test
enabled=
gpgcheck=
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-test-source]
name=Docker CE Test - Sources
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/source/test
enabled=
gpgcheck=
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-nightly]
name=Docker CE Nightly - $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/$basearch/nightly
enabled=
gpgcheck=
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-nightly-debuginfo]
name=Docker CE Nightly - Debuginfo $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/debug-$basearch/nightly
enabled=
gpgcheck=
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-nightly-source]
name=Docker CE Nightly - Sources
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/source/nightly
enabled=
gpgcheck=
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

如果是CentOS-Base.repo，则改成

 # CentOS-Base.repo
 #
 # The mirror system uses the connecting IP address of the client and the
 # update status of each mirror to pick mirrors that are updated to and
 # geographically close to the client.  You should use this for CentOS updates
 # unless you are manually picking other mirrors.
 #
 # If the mirrorlist= does not work for you, as a fall back you can try the
 # remarked out baseurl= line instead.
 #
 #

 [base]
 name=CentOS-$releasever - Base - mirrors.aliyun.com
 failovermethod=priority
 baseurl=http://mirrors.aliyun.com/centos/$releasever/os/$basearch/
         http://mirrors.aliyuncs.com/centos/$releasever/os/$basearch/
         http://mirrors.cloud.aliyuncs.com/centos/$releasever/os/$basearch/
 gpgcheck=
 gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7

 #released updates
 [updates]
 name=CentOS-$releasever - Updates - mirrors.aliyun.com
 failovermethod=priority
 baseurl=http://mirrors.aliyun.com/centos/$releasever/updates/$basearch/
         http://mirrors.aliyuncs.com/centos/$releasever/updates/$basearch/
         http://mirrors.cloud.aliyuncs.com/centos/$releasever/updates/$basearch/
 gpgcheck=
 gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7

 #additional packages that may be useful
 [extras]
 name=CentOS-$releasever - Extras - mirrors.aliyun.com
 failovermethod=priority
 baseurl=http://mirrors.aliyun.com/centos/$releasever/extras/$basearch/
         http://mirrors.aliyuncs.com/centos/$releasever/extras/$basearch/
         http://mirrors.cloud.aliyuncs.com/centos/$releasever/extras/$basearch/
 gpgcheck=
 gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7

 #additional packages that extend functionality of existing packages
 [centosplus]
 name=CentOS-$releasever - Plus - mirrors.aliyun.com
 failovermethod=priority
 baseurl=http://mirrors.aliyun.com/centos/$releasever/centosplus/$basearch/
         http://mirrors.aliyuncs.com/centos/$releasever/centosplus/$basearch/
         http://mirrors.cloud.aliyuncs.com/centos/$releasever/centosplus/$basearch/
 gpgcheck=
 enabled=
 gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7

 #contrib - packages by Centos Users
 [contrib]
 name=CentOS-$releasever - Contrib - mirrors.aliyun.com
 failovermethod=priority
 baseurl=http://mirrors.aliyun.com/centos/$releasever/contrib/$basearch/
         http://mirrors.aliyuncs.com/centos/$releasever/contrib/$basearch/
         http://mirrors.cloud.aliyuncs.com/centos/$releasever/contrib/$basearch/
 gpgcheck=
 enabled=
 gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7

或者

wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo