docker

Docker instructions

The Qt 6 app ships as a Docker image. Build once, run whenever you want.

Requirements

• Docker 20.10+ with Compose v2 (docker compose, not docker-compose) and BuildKit enabled (default on recent Docker).
• An X server reachable from the container:
  • Linux — your session already provides one.
  • WSL2 (Windows) — WSLg exposes one automatically. No extra setup.
  • Allow local Docker clients on first run: xhost +local:docker (the start.sh script does this for you).

Quick start

From the project root:

cd docker
./start.sh

That script builds the image (if needed) and launches the app. The container is removed on exit.

Equivalent by hand:

cd docker
DOCKER_BUILDKIT=1 docker compose build
docker compose run --rm app

Shared data folder

docker/data/ on the host is bind-mounted to /data inside the container. It is also the default open/save directory in the app's file dialog (via the APP_IMAGES_DIR env variable), so:

• Drop the images you want to inpaint in docker/data/ — they show up immediately when you click Import image.
• Exported images land in the same folder and are visible from the host.

Rebuilding after code changes

Thanks to BuildKit cache mounts (apt + ccache) and the layered COPY, incremental rebuilds recompile only the .cpp files you touched — typically a few seconds.

docker compose build   # rebuilds just the changed layers
./start.sh             # or: docker compose run --rm app

For a fully clean build:

docker compose build --no-cache

Display troubleshooting

The compose file sets DISPLAY=${DISPLAY:-:0}. If your X server listens on a different display, override it:

DISPLAY=:1 docker compose run --rm app

If the host's DISPLAY variable is set to something odd, unset it before running:

unset DISPLAY && ./start.sh

If Qt complains about the platform plugin, make sure the X socket is mounted (/tmp/.X11-unix, already in the compose file) and that xhost +local:docker has been run.

Distributing the image

# Save to a .tar for offline transfer
docker save -o image-inpainting-app.tar image-inpainting-app:local

# On another machine
docker load -i image-inpainting-app.tar

# Or push to a registry
docker tag image-inpainting-app:local <user>/image-inpainting-app:<tag>
docker push <user>/image-inpainting-app:<tag>