Build docker ubuntu image by Dockerfile

Question

If command "docker run ubuntu bash" the container won't last.

but if I command "docker run -it ubuntu bash" the container will make a pseudo-tty and keep this container alive.

my question is is there any way I can make a Dockerfile for building an image based on ubuntu/centos then I just need to command "docker run my-image" and the container will last.

apologize for my poor english, I don't know if my question is clear enough. thanks for any response

Answer 1

There are three ways to run containers:

• task containers - do one thing and then exit, like docker run ubuntu ls /
• interactive containers - open a connection to the container with -it , like docker run -it ubuntu bash
• background containers - keep a container running detached in the background with -d , like docker run -d ubuntu:14.04 ping localhost

Docker keeps the container running as long as there is an active process in the container. The first container exits when the ls command completes. The second container will exit when you exit the bash session. The third container will stay running as long as the ping process keeps running (note that ping has been removed from the recent Ubuntu images, which is why the example specifies 14.04).