Docker configuration

Dockerfile overview

The Dockerfile defines three final and some intermediate targets. The final targets are run_nginx, run_backend and run_celery. All build targets are described in comments in the Dockerfile itself. The graph below visualizes the build-time layer dependencies.

The images are based on Alpine Linux or on Debian. The variables DEBIAN_VER and ALPINE_VER are used to select versions of the base images. The same versions should albo be used when specifying image versions in docker-compose.yml. Using common versions let's Docker reduce the disk space used by the images.

Targets in Dockerfile

• A solid line from a to b represents the FROM a AS b instruction.
• A dashed line from a to b represents COPY --from a as a layer of target b.

flowchart TD
    nginx{{"`_nginx..._
        (alpine)`"}}
    rust{{"`_rust..._
        (alpine)`"}}
    node{{"`_node..._
        (alpine)`"}}
    uv{{"`_uv:python..._
        (debian)`"}}
        
    rust --> build_docs
    
    node --> build_webapp

    uv --> setup_base
    setup_base --> setup_django

    setup_django --> collect_static

    setup_django ---> run_backend([run_backend])

    setup_base ----> run_celery([run_celery])
    setup_django -. copy /app/backend .-> run_celery

    nginx --> run_nginx
    build_docs -. "copy /app/docs/book" ..-> run_nginx([run_nginx])
    build_webapp -. "copy /app/webapp/.output/html" .-> run_nginx([run_nginx])
    build_webapp -. "copy /app/webapp/.output/public" .-> collect_static
    collect_static -. copy /app/staticroot .-> run_nginx([run_nginx])

Django setting modules used by each target

The Django setting files used by Docker are split into several layers to allow the server admins to customize some of the settings. All the settings are part of the backend/gutenberg/settings module.

flowchart LR

base[base.py]
base ---> local(["`local_settings.py
         _(user provided_,
         _not used in Docker)_`"])
base ---> production(["`production_settings.py
         _(user provided_,
         _not used in Docker)_`"])
base --> docker_base[docker_base.py]
docker_base --> docker_settings(["`docker_settings.py
                _(user provided)_`"])
docker_settings --> docker_server_overrides[docker_server_overrides.py]

The base.py, docker_base.py and docker_server_overrides.py are all included in the repository and should not be changed by the admins.

The docker_settings.py file is not stored in the GitHub repo, it should copied by the admin from the docker_settings.py.example file and customized. docker_settings.py is ignored in .dockerignore and is not used in any build steps in the Dockerfile. It should be mounted by the admin at /etc/gutenberg/docker_settings.py and it is symlinked to be accessible from /app/backend/gutenberg/settings/docker_settings.py.

Build-time steps (like running the collectstatic command) use docker_base.py as the settings module. Run-time commands (starting the Django server and Celery worker) use docker_server_overrides.py. See the ENV DJANGO_SETTINGS_MODULE= commands in the Dockerfile.