Interactive shell using Docker Compose

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.

Solution 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.

Solution 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.

Solution 3:

In the official getting started example (https://docs.docker.com/compose/gettingstarted/) with the following docker-compose.yml:

version: '3'
services:
  web:
    build: .
    ports:
     - "5000:5000"
  redis:
    image: "redis:alpine"

After you start this with docker-compose up, you can easily shell into either your redis container or your web container with:

docker-compose exec redis sh
docker-compose exec web sh 

Solution 4:

docker-compose run myapp sh should do the deal.

There is some confusion with up/run, but docker-compose run docs have great explanation: https://docs.docker.com/compose/reference/run