Compose: build not follow the order specified

[vochicong]

docker-compose build
does not follow the order in which the services are specified.

docker-compose build base prod dev

will actually try to build in the order base, dev and prod,
which is alphabetical order and not the order specified on the command line.

[shin-]

Hi @vochicong

Thank you for your report. We don't consider this to be a bug. Is this causing issues with your application?

[vochicong]

Hi @shin- . Yes, I have dev built upon prod upon base.

#Dockerfile.base
FROM ruby
...

#Dockerfile.prod
FROM myapp-base
...

#Dockerfile.dev
FROM myapp-prod
...

#docker-compose.yml
version: '2'

services:
  base:
    image: myapp-base
    build:
      context: .
      dockerfile: Dockerfile.base

  prod:
    extends: base
    image: myapp-prod
    build:
      context: .
      dockerfile: Dockerfile.prod

  dev:
    extends: prod
    image: myapp-dev
    build:
      context: .
      dockerfile: Dockerfile.dev

[shin-]

Ok, one simple solution would be to run docker-compose build base && docker-compose build prod && docker-compose build dev instead, but if you have some time, I highly recommend you look into using multi-stage builds: https://docs.docker.com/engine/userguide/eng-image/multistage-build/

[frezbo]

@shin- I would like to re-open this, I am following multi stage builds that depends on another multi stage builds (micorservices). I would like the docker compose to build in the order specified , so that we build our common base first, then depends all our services on top of this. If the common base image exists already, compose skips it even though the Dockerfile for the base image have been changed, and the dependent images use the old image, literally wanting me to run compose twice. (BTW i dont want to use a script that builds it as compose definition is super easy to pass metadata as env variables during build).

[vochicong]

Users would expect that docker compose builds images in the order specified.
Multi-stage build is for building an image efficiently.

[cenkalti]

I run into the same problem but solved by reordering the service definitions in docker-compose.yaml file. docker-compose follows the service order defined in that file. See: https://github.com/docker/compose/blob/e9220f45df07c1f884d5d496507778d2cd4a1687/compose/project.py#L182-L183