# Quartermaster (repo instructions)

## Database safety rule

The SQLite database at `./quartermaster.db` (or whatever path
`QUARTERMASTER_DB_URL` points at) holds real user data. It is
`.gitignored`, so losing it means the data is gone.

**Before any operation that interacts with the database at the schema
or destructive level**, run:

```sh
./scripts/backup-db.sh <reason>
```

That includes:

* `rm`, `mv`, truncate, or otherwise replace `quartermaster.db`
* Ad-hoc `sqlite3` sessions that might `DROP`, `DELETE`, or `UPDATE`
* Any script that does data migration or cleanup outside the running
  application

Alembic runs `scripts/backup-db.sh alembic` automatically on every
`alembic upgrade`, `alembic downgrade`, or `alembic revision --autogenerate`
via the hook in `alembic/env.py`, so you do not need to call it
manually for ordinary schema work. The hook is defense in depth, not
a substitute for thinking.

Routine writes through the running web application are NOT covered by
this rule. Those are normal application behaviour, not "interactions"
in the sense meant here.

## Where backups go

Default: `<dir-of-db-file>/backups/quartermaster-YYYYMMDD-HHMMSS-{slug}.db`.
For the standard `./quartermaster.db` that resolves to `./backups/`.
Override with `QUARTERMASTER_BACKUP_DIR=/some/path`.

The `backups/` directory is `.gitignored`. Retention is forever:
backups are small. Prune manually if you need to.

## Restoring

A backup is a complete SQLite file. To restore, stop the app, replace
`quartermaster.db` with the chosen backup (`cp backups/... quartermaster.db`),
then restart.
