如题：　docker 安装报错：

Error: Package: containerd.io-1.2.10-3.2.el7.x86_64 (docker-ce-stable)
           Requires: container-selinux >= 2:2.74
           Available: 2:container-selinux-1.10.3-59.el7.centos.x86_64 (extras)
               container-selinux = 2:1.10.3-59.el7.centos
           Available: 2:container-selinux-1.12.5-14.el7.centos.x86_64 (extras)
               container-selinux = 2:1.12.5-14.el7.centos
           Available: 2:container-selinux-2.9-4.el7.noarch (extras)
               container-selinux = 2:2.9-4.el7
           Available: 2:container-selinux-2.10-2.el7.noarch (extras)
               container-selinux = 2:2.10-2.el7
Error: Package: 3:docker-ce-19.03.4-3.el7.x86_64 (docker-ce-stable)
           Requires: container-selinux >= 2:2.74
           Available: 2:container-selinux-1.10.3-59.el7.centos.x86_64 (extras)
               container-selinux = 2:1.10.3-59.el7.centos
           Available: 2:container-selinux-1.12.5-14.el7.centos.x86_64 (extras)
               container-selinux = 2:1.12.5-14.el7.centos
           Available: 2:container-selinux-2.9-4.el7.noarch (extras)
               container-selinux = 2:2.9-4.el7
           Available: 2:container-selinux-2.10-2.el7.noarch (extras)
               container-selinux = 2:2.10-2.el7

查了各种帖子，装各种依赖都不行，后来查到这么一个命令可以了，记录一下：

yum install --setopt=obsoletes=0 \
   docker-ce-17.03.2.ce-1.el7.centos.x86_64 \
   docker-ce-selinux-17.03.2.ce-1.el7.centos.noarch # on a new system with yum repo defined, forcing older version and ignoring obsoletes introduced by 17.06.0