Running a ubuntu container in background using docker compose

Question

I am able to run a docker container using following docker command:

docker run -it  ubuntu /bin/bash

Now I am trying to do it by using docker-compose:

version: "3"
services:
  ubuntu:
    container_name: ubuntu
    image: ubuntu
    restart: on-failure
    command: "/bin/bash"

Now when I do :

 docker-compose up -d

Can see docker container starting and exiting immediately.

I tried looking at the logs :

docker logs b8 //b8 is container id

But there are no error logs.

How do I keep ubuntu container running in background using docker. ( I am using docker on windows , linux version)

Answer 1

This is normal.

You are starting an ubuntu container with bash as the command (thus the root process). The thing is to keep bash alive you need to attach it with a terminal. This is why when you want to get a bash in a container, you're using -ti with your command :

docker container exec -ti [my_container_id] bash

So if you want to keep your ubuntu container alive and don't want to attach it to a terminal, you'll have to use a process that will stay alive for as long as you want.
Below is an example with sleep infinity as your main process

version: "3"
services:
  ubuntu:
    container_name: ubuntu
    image: ubuntu
    restart: on-failure
    command: ["sleep","infinity"]

With this example, you container will stay running indefinitely.