# Deploying Vellum

Vellum is a single Go binary in a single container with a single SQLite
database. This document covers a container deployment with `compose.yml`.

## Prerequisites

- **Podman or Docker** with the Compose plugin (`podman compose` or
  `docker compose`).
- **A media folder** on the host, laid out one directory per media kind
  (`ebooks/`, `comics/`, `audiobooks/`, `music/`, `photos/`, `games/`).
  Vellum scans these; it never writes to them.
- A host directory for the database and cache (e.g.
  `/opt/mediaserver/vellum/{data,config}`).

The image is built locally with `make docker` (Podman) or
`docker build -t localhost/vellum:0.1.0-dev .`.

## Configuration: `.env`

Every setting is an environment variable with a working default, so Vellum
starts with no configuration at all. Copy the relevant values into a `.env`
next to `compose.yml`:

```dotenv
# --- Media roots (colon-separated, read-only) -------------------------------
VELLUM_MEDIA_DIRS=/media/ebooks:/media/comics:/media/audiobooks:/media/music:/media/photos:/media/games

# --- Server -----------------------------------------------------------------
VELLUM_LISTEN=:7788
VELLUM_LOG_LEVEL=info

# --- First admin (only used on an EMPTY database) ---------------------------
VELLUM_ADMIN_USER=admin
VELLUM_ADMIN_PASSWORD=change-me-at-least-8-chars

# --- Optional metadata providers --------------------------------------------
VELLUM_COMICVINE_API_KEY=
VELLUM_IGDB_CLIENT_ID=
VELLUM_IGDB_CLIENT_SECRET=

# --- Set to true once you serve over TLS ------------------------------------
VELLUM_COOKIE_SECURE=false
```

The same names are what the process reads directly; `compose.yml` passes them
through. Defaults, for reference: `VELLUM_LISTEN=:7788`,
`VELLUM_LOG_LEVEL=info`, `VELLUM_COOKIE_SECURE=false`.

## Volumes and SELinux

`compose.yml` uses three kinds of mount:

| Mount | Mode | Purpose |
| --- | --- | --- |
| `/data` | read/write | SQLite database (`vellum.db`) and persistent state |
| `/config` | read/write | Regenerable cache: covers, thumbnails, extracted pages |
| `/media/<kind>` | **read-only** | The media library |

Each media kind is bind-mounted individually and read-only. **Vellum never
writes to `/media`.** If you add a media root, add a matching read-only mount
and a matching entry in `VELLUM_MEDIA_DIRS`.

Every bind mount carries the `:z` suffix, which is **mandatory on SELinux
hosts** (this stack runs with `getenforce = Enforcing`). Without `:z` the
container cannot read the host paths and Vellum fails to start with permission
errors. `:z` relabels the files so the container's SELinux context may access
them; `:ro` keeps the media read-only.

## First admin bootstrap

Set `VELLUM_ADMIN_USER` and `VELLUM_ADMIN_PASSWORD` (minimum 8 characters)
before the first start. On boot, if the users table is empty, Vellum creates
that administrator.

This happens **only on an empty database**. Setting these on an established
install does nothing — the credentials are ignored. If the database is empty
and both are unset, the server logs a warning and refuses to invent a default
password. Once your admin exists, remove the two variables from `.env`.

## Reverse proxy and TLS

Vellum speaks plain HTTP on `:7788`; `compose.yml` binds it to
`127.0.0.1:7788` so it is only reachable from the host. Put a reverse proxy
(nginx, Caddy, Traefik) in front of it to terminate TLS and forward to
`http://127.0.0.1:7788`.

Once traffic arrives over HTTPS, set:

```dotenv
VELLUM_COOKIE_SECURE=true
```

This marks session cookies `Secure`, so browsers only send them over TLS. When
it is `false` Vellum logs a warning at boot because session cookies can be sent
over plain HTTP. Restart the container after changing it.

## Backup

The entire persistent state is the SQLite database at `/data/vellum.db` (in
WAL mode). Two safe options:

- **Stop the container, then copy the database.**
  ```bash
  podman compose stop vellum
  cp /opt/mediaserver/vellum/data/vellum.db /backup/vellum-$(date +%F).db
  podman compose start vellum
  ```
- **Take a consistent snapshot while running** with SQLite's `VACUUM INTO`:
  ```bash
  podman exec vellum \
    sqlite3 /data/vellum.db "VACUUM INTO '/data/backup.db'"
  ```
  `VACUUM INTO` writes a single consistent file without stopping the server;
  copy that file off the volume when it is done.

`/config` holds only regenerable cache and does not need backing up.

## Upgrading

1. **Back up first** (see above). Migrations are one-way.
2. Pull or rebuild the image, then recreate the container:
   ```bash
   make docker
   podman compose up -d
   ```

**Migrations run automatically at boot.** They are embedded and applied in
filename order, recorded by number in `PRAGMA user_version`. Never edit an
applied migration; a new schema change is always a new file. If a migration
fails, the process exits and the container restarts — restore your backup.

## Logs

Vellum logs to **stdout/stderr**, so container logs are the log. With the
`json-file` driver configured in `compose.yml` (10 MB per file, 3 files):

```bash
podman logs -f vellum          # follow
podman logs --tail 100 vellum  # last 100 lines
```

Verbosity is controlled by `VELLUM_LOG_LEVEL` (`debug`, `info`, `warn`,
`error`). Set `VELLUM_LOG_FORMAT=json` for structured output if you ship logs
to a collector.