yum install docker

進入目錄/etc/yum.repos.d/下面新建檔案docker.repo，輸入以下內容

[dockerrepo]
name=Docker Repository
baseurl=https://yum.dockerproject.org/repo/main/centos/7
enabled=1
gpgcheck=1
gpgkey=https://yum.dockerproject.org/gpg

yum install docker-engine

執行上面這個步驟，可能報錯衝突的docker引擎，就直接pass這一步；

安裝完成後執行systemctl start docker.service失敗

Job for docker.service failed because the control process exited with error code. See "systemctl status docker.service" and "journalctl -xe" for details.

解決方法：

vi /etc/sysconfig/selinux    把selinux後面的改為disabled，重啟一波機器，再重啟docker就可以了

設定開機啟動Docker Daemon程序
systemctl start docker.service
systemctl enable docker.service
systemctl grep docker檢視docker程序的狀態
systemctl disable firewalld
yum -y install iptables-services
systemctl enable iptables
systemctl start iptables

問題文件留著備用：https://www.cnblogs.com/276815076/p/4673607.html