使用官方源

  yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

安装docker报错

Loaded plugins: fastestmirror, priorities

Loading mirror speeds from cached hostfile

https://download.docker.com/linux/centos/7/x86_64/stable/repodata/repomd.xml: [Errno 14] curl#7 - "Failed to connect to 2a03:2880:f10d:83:face:b00c:0:25de: Network is unreachable"

Trying other mirror.

https://download.docker.com/linux/centos/7/x86_64/stable/repodata/repomd.xml: [Errno 14] curl#7 - "Failed to connect to 2a03:2880:f10d:83:face:b00c:0:25de: Network is unreachable"

Trying other mirror.

https://download.docker.com/linux/centos/7/x86_64/stable/repodata/repomd.xml: [Errno 14] curl#7 - "Failed to connect to 2a03:2880:f10d:83:face:b00c:0:25de: Network is unreachable"

Trying other mirror.

https://download.docker.com/linux/centos/7/x86_64/stable/repodata/repomd.xml: [Errno 14] curl#7 - "Failed to connect to 2a03:2880:f10d:83:face:b00c:0:25de: Network is unreachable"

Trying other mirror.

https://download.docker.com/linux/centos/7/x86_64/stable/repodata/repomd.xml: [Errno 14] curl#7 - "Failed to connect to 2a03:2880:f10d:83:face:b00c:0:25de: Network is unreachable"

Trying other mirror.

https://download.docker.com/linux/centos/7/x86_64/stable/repodata/repomd.xml: [Errno 14] curl#7 - "Failed to connect to 2a03:2880:f10d:83:face:b00c:0:25de: Network is unreachable"

Trying other mirror.

^Chttps://download.docker.com/linux/centos/7/x86_64/stable/repodata/repomd.xml: [Errno 14] curl#56 - "Callback aborted"

Trying other mirror.

.....................

failure: repodata/repomd.xml from docker-ce-stable: [Errno 256] No more mirrors to try.

 curl#7 - "Failed to connect to 2a03:2880:f10d:83:face:b00c:0:25de: Network is unreachable"

https://download.docker.com/linux/centos/7/x86_64/stable/repodata/repomd.xml: [Errno 14] curl#56 - "Callback aborted"

这个问题可能是由于Docker官方源的问题，可以尝试更换其他的Docker源。以下是一些常用的Docker源：

阿里云：https://mirrors.aliyun.com/docker-ce/linux/centos/7.9/x86_64/stable/网易：http://hub-mirror.c.163.com/docker-ce/linux/centos/7.9/x86_64/stable/中国科技大学：https://mirrors.ustc.edu.cn/docker-ce/linux/centos/7.9/x86_64/stable/

选择一个合适的源，修改yum源配置文件

打开或创建yum源配置文件，路径为/etc/yum.repos.d/docker-ce.repo将以下内容复制到文件中（以阿里云为例）：

[docker-ce-stable]

name=Docker CE Stable - $basearch

baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7.9/x86_64/stable

enabled=1

gpgcheck=1

gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

保存文件并退出，清除缓存并重新尝试安装Docker：

sudo yum clean all

sudo yum install docker-ce

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