Monitoring Lidarr with Vigilmon

Lidarr is the music-focused member of the *arr ecosystem, automating music library management by tracking your favorite artists, monitoring release schedules, and routing downloads through your preferred clients. When Lidarr goes down, new releases go unmonitored and queued downloads stall silently. Vigilmon catches these failures immediately — monitoring Lidarr's web interface, API health, and download client connectivity so your music automation keeps running without gaps.

What You'll Set Up

• Web UI availability monitor on Lidarr's default port
• API health check via the /api/v1/system/status endpoint
• Download client connectivity monitoring via response content
• Music metadata provider availability check
• SSL certificate alerts for reverse-proxied installations

Prerequisites

• Lidarr installed and running (via Docker, Unraid, or bare metal)
• Your Lidarr API key (Settings → General → API Key)
• A free Vigilmon account

Step 1: Monitor the Lidarr Web UI

Lidarr's web interface runs on port 8686 by default. Start with a basic HTTP monitor:

1. Log in to vigilmon.online and click Add Monitor.
2. Set Type to HTTP / HTTPS.
3. Enter your Lidarr URL: http://192.168.1.100:8686 (or your reverse proxy domain).
4. Set Check interval to 2 minutes.
5. Set Expected HTTP status to 200.
6. Click Save.

This is your first-level alert for when the Mono/.NET process backing Lidarr crashes or the container exits. If Lidarr is only accessible on your home network, deploy a Vigilmon agent on the same LAN segment.

Step 2: Check the Lidarr System Status API

Lidarr's REST API includes a /api/v1/system/status endpoint that returns detailed information about the running instance: version, OS, database status, and startup time. This gives you a richer health signal than a plain UI check:

1. Add another HTTP / HTTPS monitor.
2. Enter http://192.168.1.100:8686/api/v1/system/status.
3. Expand Request Headers and add:
   • Header: X-Api-Key
   • Value: your_lidarr_api_key
4. Set Expected HTTP status to 200.
5. Under Response body check, enter version to confirm the response contains application version data.
6. Set Check interval to 3 minutes.
7. Click Save.

A healthy response includes:

{
  "version": "2.4.3.4248",
  "buildTime": "2024-06-01T00:00:00Z",
  "isDebug": false,
  "isProduction": true,
  "appName": "Lidarr",
  "startupPath": "/app/lidarr"
}

The version field confirms the application layer is responding. If Lidarr is partially started or in a crash loop, this endpoint returns an error before the web UI becomes obviously broken.

Step 3: Monitor Download Client Connectivity

Lidarr integrates with download clients like qBittorrent, Deluge, SABnzbd, or NZBGet. If the download client goes offline, Lidarr queues up tasks that never execute — releases get marked as grabbed but never downloaded. Use the Lidarr health check API to monitor this:

1. Add an HTTP / HTTPS monitor for http://192.168.1.100:8686/api/v1/health.
2. Add the X-Api-Key header as in Step 2.
3. Set Expected HTTP status to 200.
4. Under Response body check, enter [] to confirm an empty health check array (no warnings).

Alternatively, check for the absence of download client errors by ensuring the response doesn't contain DownloadClientError:

• Under Response body check, configure an alert if the response contains DownloadClientError.

This catches the common scenario where your download client crashes but Lidarr continues running and appearing healthy in the web UI.

Step 4: Check Music Metadata Provider Availability

Lidarr uses MusicBrainz as its primary metadata provider. If MusicBrainz is unreachable (rate limiting, temporary outage, or network issues), Lidarr can't identify new releases or update artist metadata. Monitor this via Lidarr's health endpoint:

1. Edit the /api/v1/health monitor from Step 3.
2. Add a response body check to detect MusicBrainzError — this appears in the health response when the metadata provider is unavailable.

You can also monitor your Lidarr instance's ability to reach external services by adding a separate TCP connectivity check to musicbrainz.org on port 443:

1. Add a new TCP monitor in Vigilmon.
2. Set Host to musicbrainz.org and Port to 443.
3. Set Check interval to 10 minutes.

This gives you an early warning when metadata lookups will fail before Lidarr logs errors.

Step 5: SSL Certificate Alerts

If Lidarr is exposed via a reverse proxy (nginx, Caddy, Traefik) with HTTPS, add an SSL certificate monitor:

1. Open your Lidarr HTTP monitor using the domain URL.
2. Enable Monitor SSL certificate under the SSL section.
3. Set Alert when certificate expires in less than 21 days.
4. Click Save.

For Docker-based setups using a Traefik or nginx reverse proxy container, certificate renewal depends on the proxy container being healthy — another reason to monitor the entire stack rather than just Lidarr itself.

Step 6: Configure Alert Channels

1. Go to Alert Channels in Vigilmon and add your preferred notification channel: email, Slack, Discord, or a webhook to your home automation platform.
2. Set Consecutive failures before alert to 2 on the web UI and API monitors — Lidarr takes 15–30 seconds to restart after a crash and re-initialize its SQLite database.
3. Set Consecutive failures before alert to 1 for the health API monitor — download client failures need immediate attention so queued downloads don't pile up.
4. Use Maintenance windows in Vigilmon around planned Lidarr upgrades to suppress false alerts during restarts.

Summary

| Monitor | Target | What It Catches | |---|---|---| | Web UI | http://lidarr-host:8686 | Process crash, container exit | | System status API | /api/v1/system/status with API key | Application layer failure | | Health API | /api/v1/health | Download client errors, warnings | | Metadata provider | TCP musicbrainz.org:443 | MusicBrainz unreachable | | SSL certificate | Proxied domain | Certificate expiry |

Lidarr's value is in automating what would otherwise be hours of manual release tracking and downloading. When it fails silently, you don't find out until you notice your library is months out of date. With Vigilmon covering the web UI, API health, download client connectivity, and metadata providers, your music automation stack stays visible and accountable — so releases keep arriving without you having to babysit the system.