Docker Compose keep container running

Based on the comment of @aanand on GitHub Aug 26, 2015, one could use tail -f /dev/null in docker-compose to keep the container running.

docker-compose.yml example

version: '3'
services:
  some-app:
    command: tail -f /dev/null

Why this command?

The only reason for choosing this option was that it received a lot of thumbs up on GitHub, but the highest voted answer does not mean that it is the best answer. The second reason was a pragmatic one as issues had to be solved as soon as possible due to deadlines.

To keep a container running when you start it with docker-compose, use the following command

command: tail -F anything

In the above command the last part anything should be included literally, and the assumption is that such a file is not present in the container, but with the -F option (capital -F not to be confused with -f which in contrast will terminate immediateley if the file is not found) the tail command will wait forever for the file anything to appear. A forever waiting process is basically what we need.

So your docker-compose.yml becomes

version: '2'
services:
  my-test:
    image: ubuntu
    command: tail -F anything

and you can run a shell to get into the container using the following command

docker exec -i -t composename_my-test_1 bash

where composename is the name that docker-compose prepends to your containers.

You can use tty configuration option.

version: '3'

services:
  app:
    image: node:8
    tty: true           # <-- This option

Note: If you use Dockerfile for image and CMD in Dockerfile, this option won't work; however, you can use the entrypoint option in the compose file which clears the CMD from the Dockerfile.