今天在服务器上安装docker时遇到一些问题。
第一步：yum安装docker;
yum install docker
启动docker；
systemctl start docker
到这里的时候就报错了，错误信息如下：
[huangpeng@centos-linux ~]$ sudo service docker start Redirecting to /bin/systemctl start docker.service Job for docker.service failed because the control process exited with error code. See "systemctl status docker.service" and "journalctl -xe" for details.
按照它的说法，我运行
systemctl status -l docker.service
这个命令，加了-l参数是因为不加字符显示不全。然后看到：
docker.service - Docker Application Container Engine Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled) Active: failed (Result: exit-code) since 五 2018-08-03 15:31:27 HKT; 3min 2s ago Docs: http://docs.docker.com Process: 29122 ExecStart=/usr/bin/dockerd-current --add-runtime docker-runc=/usr/libexec/docker/docker-runc-current --default-runtime=docker-runc --exec-opt native.cgroupdriver=systemd --userland-proxy-path=/usr/libexec/docker/docker-proxy-current --init-path=/usr/libexec/docker/docker-init-current --seccomp-profile=/etc/docker/seccomp.json $OPTIONS $DOCKER_STORAGE_OPTIONS $DOCKER_NETWORK_OPTIONS $ADD_REGISTRY $BLOCK_REGISTRY $INSECURE_REGISTRY $REGISTRIES (code=exited, status=1/FAILURE) Main PID: 29122 (code=exited, status=1/FAILURE)8月 03 15:31:25 centos-linux.shared systemd[1]: Starting Docker Application Container Engine... 重点是下面这一句：8月 03 15:31:25 centos-linux.shared dockerd-current[29122]: time="2018-08-03T15:31:25.721701961+08:00" level=warning msg="could not change group /var/run/docker.sock to docker: group docker not found"8月 03 15:31:25 centos-linux.shared dockerd-current[29122]: time="2018-08-03T15:31:25.725025504+08:00" level=info msg="libcontainerd: new containerd process, pid: 29127"8月 03 15:31:27 centos-linux.shared dockerd-current[29122]: Error starting daemon: SELinux is not supported with the overlay2 graph driver on this kernel. Either boot into a newer kernel or disable selinux in docker (--selinux-enabled=false)8月 03 15:31:27 centos-linux.shared systemd[1]: docker.service: main process exited, code=exited, status=1/FAILURE8月 03 15:31:27 centos-linux.shared systemd[1]: Failed to start Docker Application Container Engine.8月 03 15:31:27 centos-linux.shared systemd[1]: Unit docker.service entered failed state.8月 03 15:31:27 centos-linux.shared systemd[1]: docker.service failed.
could not change group /var/run/docker.sock to docker: group docker not found说明没有docker这个用户组，然后谷歌一下，发现需要自己创建用户组，于是。
sudo groupadd docker sudo usermod -aG docker $(whoami) 先退出一下再重新登录来保证有了正确的权限 sudo service docker start
然后再启动，又报了错，不过这次不一样了
Error starting daemon: SELinux is not supported with the overlay2 graph driver on this kernel. Either boot into a newer kernel or disable selinux in docker (--selinux-enabled=false)
意思是说：此linux的内核中的SELinux不支持 overlay2 graph driver ，解决方法有两个，要么启动一个新内核，要么就在docker里禁用selinux，--selinux-enabled=false.
重新编辑docker配置文件：
vi /etc/sysconfig/docker
改为：--selinux-enabled=false
image.png
再次启动一下docker，就好了。
作者：lunabird
链接：https://www.jianshu.com/p/45d158a45582