一 启动进入容器指定bash 退出后容器关闭
[root@Centos-node3 ~]# docker run -it centos bash
[root@83c6b25aca09 /]#
二 docker attach进入容器后退出 如果容器没有指定bash环境会停留在空白页面 退出后容器也会正常退出（进入容器后其他人进入容器可以看到你输入的信息）
[root@Centos-node3 ~]# docker run -it -d --name mynginx nginx /bin/bash
c23ba383b76baa6c3e1a9450e23e6e4f46724a4e2b8e8c2b8c002e54ba2e5f32
[root@Centos-node3 ~]# docker attach mynginx
root@c23ba383b76b:/# ls
bin dev home lib64 mnt proc run srv tmp var
boot etc lib media opt root sbin sys usr
root@c23ba383b76b:/# exit
exit
[root@Centos-node3 ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
三 docker exec 进入容器 会启用一个bash环境
[root@Centos-node3 ~]# docker run -it -d --name mycentos centos /bin/bash
68e1f711a4990f66ad3456b453591c3fa9a7d22d4fed3e50bda1cf27a36cc60a
[root@Centos-node3 ~]# docker exec -it mycentos bash
[root@68e1f711a499 /]# ps -ef
PID TTY TIME CMD
? :: bash
? :: bash
? :: ps
[root@68e1f711a499 /]# exit
exit
[root@Centos-node3 ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
68e1f711a499 centos "/bin/bash" About a minute ago Up About a minute mycentos
c23ba383b76b nginx "/bin/bash" minutes ago Up minutes /tcp mynginx
[root@Centos-node3 ~]# docker exec -it mycentos ls
anaconda-post.log devhome lib64 mnt procrun srv tmpvar
bin etclib media opt rootsbin sys usr
四 nsenter
yum -y install util-linux #安装nsenter命令
[root@Centos-node3 ~]# docker inspect -f "{{ .State.Pid }}" mycentos
30428 #查看容器pid
nsenter -t -m -u -i -n -p
-t：指定PID
–u：参数是进入到uts namespace中
–i：参数是进入到System V IPC namaspace中
–n：参数是进入到network namespace中
–p：参数是进入到pid namespace中
脚本方式进入（可直接传参docker name 或者ID）
[root@Centos-node2 ~]# cat docker_in.sh
#!/bin/bash #Use nsenter to access docker docker_in(){
NAME_ID=$
PID=$(docker inspect -f "{{ .State.Pid }}" $NAME_ID)
nsenter -t $PID -m -u -i -n -p
} docker_in $