Monitoring

Prometheus metrics, packet logs, and live packet stream

Graywolf provides several monitoring interfaces for observing station activity and diagnosing issues.

Packet Logs page showing live packet stream with callsigns, directions, and decoded info

The packet log viewer with live streaming, search filtering, and CSV export

Web UI Dashboard

The web UI dashboard shows real-time station status including uptime, per-channel statistics (RX/TX frame counts, DCD state, audio peak levels), and iGate connection status. The Logs page provides a live packet stream with filtering by direction and channel.

Prometheus Metrics

Graywolf exposes a Prometheus-compatible /metrics endpoint on the HTTP port. Point your Prometheus scrape config at it to collect station telemetry.

prometheus.yml (excerpt)

scrape_configs:
  - job_name: graywolf
    static_configs:
      - targets: ['graywolf-host:8080']

Available Metrics

Radio & Modem

Metric	Type	Description
`graywolf_rx_frames_total`	counter	Received packets (label: `channel`)
`graywolf_tx_frames_total`	counter	Transmitted packets (label: `channel`)
`graywolf_dcd_active`	gauge	Data carrier detect state (label: `channel`)
`graywolf_audio_level`	gauge	Peak audio level 0–1 (label: `channel`)
`graywolf_child_up`	gauge	Rust modem process alive (1) or dead (0)
`graywolf_child_restarts_total`	counter	Modem crash/restart count

TX Governor

Metric	Type	Description
`graywolf_tx_deduped_total`	counter	Duplicate TX packets suppressed
`graywolf_tx_rate_limited_total`	counter	Packets dropped by rate limiter

APRS Features

Metric	Type	Description
`graywolf_digipeater_packets_total`	counter	Packets digipeated
`graywolf_beacon_packets_total`	counter	Beacon transmissions (label: `type`)
`graywolf_igate_rf_to_is_gated_total`	counter	Packets gated from RF to APRS-IS
`graywolf_igate_is_to_rf_gated_total`	counter	Packets gated from APRS-IS to RF

Interfaces

Metric	Type	Description
`graywolf_kiss_clients_active`	gauge	Connected KISS clients (label: `interface`)
`graywolf_agw_clients_active`	gauge	Connected AGWPE clients
`graywolf_gps_parse_errors_total`	counter	GPS parse errors (label: `source`)

Packet Log API

The packet log maintains a ring buffer of the most recent packets (up to 1000 entries, 30-minute age limit). Query it via the REST API or view it in real time through the web UI.

Method	Endpoint	Description
GET	`/api/packets`	Query packet history (filterable by time, direction, channel)
WebSocket	`/ws/packets`	Live packet stream

Packet Entry Fields

Field	Description
`timestamp`	ISO 8601 timestamp
`channel`	Radio channel number
`direction`	`RX`, `TX`, or `IS`
`source`	Origin: `modem`, `kiss`, `agw`, `beacon`, `digi`, `igate-tx`, `igate-is`
`display`	Human-readable packet string
`type`	APRS type: `position`, `message`, `weather`, etc.
`decoded`	Parsed APRS data (position, message, telemetry objects)
`raw`	Base64-encoded raw AX.25 frame

Health Check

A lightweight health endpoint is available for load balancers and monitoring systems:

GET /api/health

{
  "status": "ok",
  "time": "2026-04-11T10:00:00Z",
  "started_at": "2026-04-11T08:30:00Z"
}

Status Endpoint

The status endpoint returns aggregated dashboard data in a single request — uptime, per-channel stats (RX/TX counts, DCD state, audio peak), and iGate connection status:

GET /api/status

Logging

Graywolf outputs structured logs to stderr. By default, logs are at INFO level. Enable verbose logging with the -debug flag.

When running under systemd, logs are captured by the journal and queryable with:

journalctl -u graywolf -f

✓

Debug logging includes per-packet decode details, IPC message traces, and CSMA timing decisions. Enable it when troubleshooting decode or transmission issues.