Managing Dofigen in the build section

[taorepoara]

Description

Dofigen help creating Dockerfiles by defining the structure using YAML.

Managing Dofigen to make it usable instead of the Dockerfile field to define the Dofigen file:

services:
  webapp:
    build:
      context: .
      dofigen: dofigen.yml

Or directly define it like in the next example the builds a TypeScript project:

services:
  webapp:
    build:
      context: .
      dofigen: 
        builders:
          - name: module-loader
            from: &image "docker.io/bitnami/node:18"
            workdir: /tmp/module
            adds:
              - package.json
              - package-lock.json
            script:
              - npm ci --omit=dev --cache /tmp/cache
            caches:
              - /tmp/cache
          - name: builder
            from: *image
            workdir: /tmp/app
            adds:
              - .
            script:
              - npm i --cache /tmp/cache
              - npm run build
            caches:
              - /tmp/cache
        from: *image
        workdir: /app
        artifacts:
          - builder: module-loader
            source: "/tmp/module/"
            destination: "/app/"
          - builder: builder
            source: "/tmp/app/dist/"
            destination: "/app/dist/"
          - builder: builder
            source: "/tmp/app/resources/"
            destination: "/app/resources/"
        cmd:
          - node
          - node_modules/@lenra/app-server/dist/bin/app-lenra.js
        ports:
          - 3000
        envs:
          NODE_ENV: production
        ignores:
          - "**"
          - "!/*.json"
          - "!/src/"
          - "!/resources/"

[ndeloof]

Changes in the compose file format should be discussed on github.com/compose-spec/compose-spec.
Anyway, I don't expect we approve introducing into the compose-spec schema support for a nested format. Anyway it makes sense imho we don't get stuck with docker build approach for building images from a Dockerfile.

I suggest we investigate the ability to declare a configurable image builder:

services:
  webapp:
      build:
          context: .
          image-builder: # defaults to `docker`

with this set, docker compose build could then delegate image build to third party tool. For your example this would result into:

services:
  webapp:
      build:
          context: .
          image-builder: dofigen
          x-dofigen-file: dofigen.yml  # custom extension can be used to pass parameters to plugable image builder

This could also be used to force use of buildkit, even when disabled by configuration, as Dockerfile might require advanced features and would fail with the classic builder.

Same would allow to integrate dotnet publish or any comparable solution

[taorepoara]

Actually, Dofigen is not a builder, it only generate the Dockerfile and .dockerignore, but I uderstand the point. I'll think to make it generic and I'll propose it on compose-spec.

[ndeloof]

I'm closing this issue as such discussion should take place under compose specification.