[davior]

Problem

docker-compose.yml already mounts all of ./data at /app/data, but the app wasn't writing there.

With no DATA_DIR set, config.py derives the data directory from its own location: Path(__file__).resolve().parents[2] / "data". That works for a local checkout (backend/app/config.py → repo root). In the image, though, the file sits at /app/app/config.py, so parents[2] is / and everything is written to /data, outside the volume.

Only the database survived a rebuild, because DATABASE_URL is set explicitly. Everything else under the data directory was lost every time:

• finished renders (renders/),
• the cache of GAM files a render fetched,
• pictures attached to the assistant (added in Let the assistant work from attached files, pictures, notes and web pages #9).

Fix

• backend/Dockerfile: ENV DATA_DIR=/app/data, so the image is correct even when run without compose.
• docker-compose.yml: DATA_DIR=/app/data beside DATABASE_URL, with a comment on why it is load-bearing.
• CLAUDE.md: the deploy note now says all of data/ is mounted, not just data/db/.

GAM isn't affected: its compose already sets MEDIA_DIR explicitly.

Testing

• I reproduced the image layout (app/ copied under a root directory) and printed settings.resolved_data_dir. Without the variable it resolves to the parent of the root plus /data, which is /data in the image. With DATA_DIR=/app/data it resolves to /app/data.
• docker-compose.yml still parses.
• I couldn't build the image in this environment (no Docker daemon). CI's Docker build job will check that.
• Existing renders recorded in the database whose files are already gone stay gone. This change only keeps new ones.

---

Generated by Claude Code