Compose: Allow compose to accept arbitrary command on 'up'

[velvetcat]

and override the appropriate service/command clause in the docker-compose.yml

Usage:
up [options] [SERVICE [COMMAND [ARGS...]]]

This will allow reusing services in a more flexible way.

[aanand]

This is what docker-compose run is for:

Run a one-off command on a service.

For example:

    $ docker-compose run web python manage.py shell

By default, linked services will be started, unless they are already
running. If you do not want to start linked services, use
`docker-compose run --no-deps SERVICE COMMAND [ARGS...]`.

Usage: run [options] [-p PORT...] [-e KEY=VAL...] SERVICE [COMMAND] [ARGS...]

Options:
    -d                    Detached mode: Run container in the background, print
                          new container name.
    --name NAME           Assign a name to the container
    --entrypoint CMD      Override the entrypoint of the image.
    -e KEY=VAL            Set an environment variable (can be used multiple times)
    -u, --user=""         Run as specified username or uid
    --no-deps             Don't start linked services.
    --rm                  Remove container after run. Ignored in detached mode.
    -p, --publish=[]      Publish a container's port(s) to the host
    --service-ports       Run command with the service's ports enabled and mapped
                          to the host.
    -T                    Disable pseudo-tty allocation. By default `docker-compose run`
                          allocates a TTY.
    -w, --workdir=""      Working directory inside the container

[velvetcat]

Doesn't the "one-off" term imply some conceptual limitations? And real, for example, the "run" command doesn't aggregate logs from the containers.

P.S. Just noted that "up SERVICE" doesn't aggregate logs as well.

[aanand]

What are you trying to achieve?

[velvetcat]

I have the following docker-compose.yml (the most important part of):

version: '2'

services:

  node:
    build:
      context: .
      dockerfile: dockerfile-node
    ports:
      - 3000:3000

  test:
    extends:
      service: node
    volumes_from:
      - sources
    working_dir: /src
    command: npm test

  prod:
    extends:
      service: node
    volumes_from:
      - sources
    working_dir: /src
    command: npm start

  sources:
    build:
      context: .
      dockerfile: dockerfile-sources

The 'services' test and prod both extend the node one and only differ in the command to execute. I would like to get rid of that test and prod pseudo services to remove duplication, and cast up with a command to execute inside the containers.

Actually, the run command suits that very well, but I'm afraid of present and future conceptual issues.

Thank you very much.

[aanand]

This sounds like exactly what run is for. All that's meant by "one-off" is that run is not designed for long-running, always-up containers. Try this:

version: '2'

services:
  node:
    build:
      context: .
      dockerfile: dockerfile-node
    ports:
      - 3000:3000
    volumes_from:
      - sources
    working_dir: /src
    command: npm start

  sources:
    build:
      context: .
      dockerfile: dockerfile-sources

To run the production command:

$ docker-compose up

To run the test command:

$ docker-compose run node npm test

You can always shove that last command into a Makefile if you don't want to repeat it all the time.

Alternatively, you can additionally define a test override file, say docker-compose.test.yml:

version: "2"

services:
  node:
    command: npm test

And then run:

$ docker-compose -f docker-compose.yml -f docker-compose.test.yml up

But that's significantly more typing for a pretty simple use case.

[velvetcat]

Thank you so much for so complete answer. Definitely these cases are enough for me.