Interactive shell using Docker Compose

Question

Is there any way to start an interactive shell in a container using Docker Compose only? I've tried something like this, in my docker-compose.yml:

myapp:   image: alpine:latest   entrypoint: /bin/sh 

When I start this container using docker-compose up it's exited immediately. Are there any flags I can add to the entrypoint command, or as an additional option to myapp, to start an interactive shell?

I know there are native docker command options to achieve this, just curious if it's possible using only Docker Compose, too.

Answer 1

You need to include the following lines in your docker-compose.yml:

version: "3" services:   app:     image: app:1.2.3     stdin_open: true # docker run -i     tty: true        # docker run -t  

The first corresponds to -i in docker run and the second to -t.

Answer 2

The canonical way to get an interactive shell with docker-compose is to use:

docker-compose run --rm myapp 

(With the service name myapp taken from your example. More general: it must be an existing service name in your docker-compose file, myapp is not just a command of your choice. Example: bash instead of myapp would not work here.)

You can set stdin_open: true, tty: true, however that won't actually give you a proper shell with up, because logs are being streamed from all the containers.

You can also use

docker exec -ti <container name> /bin/bash 

to get a shell on a running container.