1.随便下载一个ubuntu或centos的镜像,如centos:7.4.1708版本。
2.执行如何命令，一定要加上”-it -d”的交互指令,这两个指令其在后台执行，并默认执行交互动作。

docker run --name lnmp-build -itd -v /home/abc/build/lnmp/lnmp1.4-full:/lnmp1.4-full  centos:7.4.1708 /bin/bash
或
docker run --name lnmp-build -itd -v /home/abc/build/lnmp/lnmp1.4-full:/lnmp1.4-full  centos:7.4.1708
#必须带上-it -d参数，
#若只有-d参数时，由于centos没有相应的CMD指令，则会主动退出，且下一次即使docker start mytest也只是容器启动后，马上退出。
#若只有-it参数，则会直接进行交互模式，程序退出后，容器结束执行，但可以使用docker start mytest启动，并不会主动退出。
#交互模式下，不需要指定/bin/bash参数，若指定则相应运算该cmd参数。

3.进入交互模式

docker exec -it lnmp-build /bin/bash
或
docker attach lnmp-build
#前者会新创建一个终端，进行交互，后者会使用现有的终端进行交互。

sudo groupadd docker
sudo usermod -aG dockerroot abc
sudo usermod -aG docker abc
cat /etc/group #检查是否生效。
sudo systemctl restart docker，重启docker镜像
如果提示权限不够，如下：
Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get http://%2Fvar%2Frun%2Fdocker.sock/v1.26/containers/json: dial unix /var/run/docker.sock: connect: permission denied
则修改/var/run/docker.sock权限.
sudo chmod a+rw /var/run/docker.sock

docker logs –follow –tail 10

在使用systemctl start docker启动失败时，使用systemctl status docker.service其报告如下：

docker.service - Docker Application Container Engine
   Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Fri 2018-04-27 02:38:36 EDT; 12s ago
     Docs: http://docs.docker.com
  Process: 2356 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 --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: 2356 (code=exited, status=1/FAILURE)

Apr 27 02:38:35 localhost.localdomain systemd[1]: Starting Docker Application Container Engine...
Apr 27 02:38:35 localhost.localdomain dockerd-current[2356]: time="2018-04-27T02:38:35.166869440-04:00" level=warning msg="could not change group /var/run/docker.sock to docker: group docker not found"
Apr 27 02:38:35 localhost.localdomain dockerd-current[2356]: time="2018-04-27T02:38:35.171487584-04:00" level=info msg="libcontainerd: new containerd process, pid: 2361"
Apr 27 02:38:36 localhost.localdomain dockerd-current[2356]: 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)
Apr 27 02:38:36 localhost.localdomain systemd[1]: docker.service: main process exited, code=exited, status=1/FAILURE
Apr 27 02:38:36 localhost.localdomain systemd[1]: Failed to start Docker Application Container Engine.
Apr 27 02:38:36 localhost.localdomain systemd[1]: Unit docker.service entered failed state.
Apr 27 02:38:36 localhost.localdomain systemd[1]: docker.service failed.

截图如下：

此处意思是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,
解决办法如下：

vi /etc/sysconfig/docker