How can I run docker container without entering into container

Question

I have Dockefile

FROM centos:7

So I have no entrypoint in dockerfile. Then I build it to image

sudo docker build -t my_container .

Then I start it.

sudo docker run -t my_container

And I get open tty to container

root@my_container_id/

If I start it without -t it stopped immidiately after start. How can I run docker container without start tty and without entrypoint?

Solution 1

You can start your container in a detached mode:

docker run -it -d my_container

The -d option here means your container will run in "detached" mode, in the background.

If you want to attach the container and drop to a shell, you can use:

docker exec -it my_container /bin/bash

Note, if your container is based on an alpine image, you need to use sh, i.e.:

docker exec -it my_container /bin/sh 

Solution 2

You can't do that. Your container lives if its main process is running, so you have to have a main process which is the process with PID 1 inside your container, and your container will be up if that process is running.