🎵 lyrion-sync

Automatically syncs favorite albums from Lyrion Music Server to a local directory — packaged as a Docker container with a configurable cron schedule.

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How It Works

Lyrion Music Server (LMS)
        │
        │  JSON-RPC API
        ▼
  ┌─────────────┐
  │   sync.py   │  1. Load all albums & build index
  │             │  2. Fetch favorite albums for player
  │             │  3. Resolve track URLs per album
  │             │  4. Write rsync filter playlist
  └──────┬──────┘
         │
         │  rsync --filter
         ▼
  Music source directory  ──►  Sync target directory

The container runs continuously and executes sync.py on the configured cron schedule. If the LMS is unreachable at the time of execution, the run is silently skipped — the next cron trigger will try again automatically.

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Requirements

• Docker & Docker Compose
• Lyrion Music Server (LMS) reachable on the network

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Quick Start

# 1. Clone the repository
git clone https://github.com/Bitpainter75/lyrion-sync.git
cd lyrion-sync

# 2. Edit docker-compose.yml  →  set LMS IP, paths, cron schedule
nano docker-compose.yml

# 3. Build and start the container
docker compose up -d --build

# 4. Follow live logs
docker compose logs -f

On first start — if SYNC_ON_START=true (default) — a sync runs immediately. After that, the cron schedule takes over.

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Repository Structure

lyrion-sync/
├── sync.py            # Main script: LMS query → playlist → rsync
├── entrypoint.sh      # Container entry point: cron setup + optional immediate run
├── Dockerfile         # Python 3.12 Slim + rsync + cron
├── docker-compose.yml # All parameters configured as environment variables
├── requirements.txt   # Python dependencies (only: requests)
└── README.md

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Configuration

All parameters are set as environment variables in docker-compose.yml — no rebuild required after changes.

Lyrion Music Server

Variable	Default	Description
LMS_HOST	http://10.3.3.3:9002	LMS URL including port
LMS_PLAYER_ID	30:30:30:30:30:30	MAC address / player ID of the client
LMS_TIMEOUT	10	HTTP timeout in seconds

Scheduling

Variable	Default	Description
CRON_SCHEDULE	0 3 * * *	Cron expression (default: daily 03:00)
SYNC_ON_START	true	Run a sync immediately on container start

Cron Examples

Expression	Meaning
0 3 * * *	Every day at 03:00
*/30 * * * *	Every 30 minutes
0 */6 * * *	Every 6 hours
0 2 * * 0	Every Sunday at 02:00

Tip: Generate cron expressions interactively at crontab.guru

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Volumes

Host paths are mapped to container paths in docker-compose.yml:

volumes:
  - /host/path/music:/music:ro    # Music source (read-only recommended)
  - /host/path/sync:/sync         # rsync target
  - /host/path/data:/data         # Playlist output + log files

The music source directory is mounted :ro (read-only) — the container does not need write access there.

The /data directory also contains the log files, one per sync run:

File	Description
2026-05-26_14-30-00_lyrion-sync.log	Example log file for a single run

Log files older than 5 days are deleted automatically at the start of each run.

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Behavior When LMS Is Unreachable

Cron trigger
     │
     ▼
LMS reachable?
  No  ──► exit 0  (silent skip, no error alert)
            │
            └── Cron keeps running, retries on next trigger
  Yes ──► Sync proceeds normally

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LMS Also Running in Docker?

Option A – Host network (simplest):

services:
  lyrion-sync:
    network_mode: host

Option B – Shared Docker network:

networks:
  lyrion-sync:
    external: true          # must already exist

services:
  lyrion-sync:
    networks:
      - lms-net

Then set LMS_HOST to the LMS container name, e.g. http://lms:9002.

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Useful Commands

# Check container status
docker compose ps

# Follow live logs
docker compose logs -f

# Trigger a sync immediately (without waiting for cron)
docker compose exec lyrion-sync python /app/sync.py

# Restart after configuration changes
docker compose up -d

# Stop the container
docker compose down

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Sync Process in Detail

1. Reachability check — HTTP GET to LMS_HOST. On failure: exit 0, skip run.
2. Album index — All albums in LMS are loaded via JSON-RPC and indexed as favorites_url → album_id.
3. Favorites — The favorites list of the configured player is fetched (want_url:1).
4. Track URLs — For each favorite album, track URLs are resolved (tags:u).
5. Write playlist — An rsync filter file is generated:

   + */
   + *[*10]
   + /Artist/Album/track.flac
   ...
   - *
   

6. UTF-8 BOM is stripped via sed for rsync compatibility.
7. rsync — Syncs MUSIC_BASE_PATH → MUSIC_SYNC_PATH using the playlist (--delete-excluded, --prune-empty-dirs).

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License

MIT — see LICENSE