add docs for metrics

docs/docs/configuration/metrics.md

@@ -0,0 +1,99 @@
+---
+id: metrics
+title: Metrics
+---
+
+# Metrics
+
+Frigate exposes Prometheus metrics at the `/metrics` endpoint that can be used to monitor the performance and health of your Frigate instance.
+
+## Available Metrics
+
+### System Metrics
+- `frigate_cpu_usage_percent{pid="", name="", process="", type="", cmdline=""}` - Process CPU usage percentage
+- `frigate_mem_usage_percent{pid="", name="", process="", type="", cmdline=""}` - Process memory usage percentage
+- `frigate_gpu_usage_percent{gpu_name=""}` - GPU utilization percentage
+- `frigate_gpu_mem_usage_percent{gpu_name=""}` - GPU memory usage percentage
+
+### Camera Metrics
+- `frigate_camera_fps{camera_name=""}` - Frames per second being consumed from your camera
+- `frigate_detection_fps{camera_name=""}` - Number of times detection is run per second
+- `frigate_process_fps{camera_name=""}` - Frames per second being processed
+- `frigate_skipped_fps{camera_name=""}` - Frames per second skipped for processing
+- `frigate_detection_enabled{camera_name=""}` - Detection enabled status for camera
+- `frigate_audio_dBFS{camera_name=""}` - Audio dBFS for camera
+- `frigate_audio_rms{camera_name=""}` - Audio RMS for camera
+
+### Detector Metrics
+- `frigate_detector_inference_speed_seconds{name=""}` - Time spent running object detection in seconds
+- `frigate_detection_start{name=""}` - Detector start time (unix timestamp)
+
+### Storage Metrics
+- `frigate_storage_free_bytes{storage=""}` - Storage free bytes
+- `frigate_storage_total_bytes{storage=""}` - Storage total bytes
+- `frigate_storage_used_bytes{storage=""}` - Storage used bytes
+- `frigate_storage_mount_type{mount_type="", storage=""}` - Storage mount type info
+
+### Service Metrics
+- `frigate_service_uptime_seconds` - Uptime in seconds
+- `frigate_service_last_updated_timestamp` - Stats recorded time (unix timestamp)
+- `frigate_device_temperature{device=""}` - Device Temperature
+
+### Event Metrics
+- `frigate_camera_events{camera="", label=""}` - Count of camera events since exporter started
+
+## Configuring Prometheus
+
+To scrape metrics from Frigate, add the following to your Prometheus configuration:
+
+```yaml
+scrape_configs:
+  - job_name: 'frigate'
+    metrics_path: '/metrics'
+    static_configs:
+      - targets: ['frigate:5000']
+    scrape_interval: 15s
+```
+
+## Example Queries
+
+Here are some example PromQL queries that might be useful:
+
+```promql
+# Average CPU usage across all processes
+avg(frigate_cpu_usage_percent)
+
+# Total GPU memory usage
+sum(frigate_gpu_mem_usage_percent)
+
+# Detection FPS by camera
+rate(frigate_detection_fps{camera_name="front_door"}[5m])
+
+# Storage usage percentage
+(frigate_storage_used_bytes / frigate_storage_total_bytes) * 100
+
+# Event count by camera in last hour
+increase(frigate_camera_events[1h])
+```
+
+## Grafana Dashboard
+
+You can use these metrics to create Grafana dashboards to monitor your Frigate instance. Here's an example of metrics you might want to track:
+
+- CPU, Memory and GPU usage over time
+- Camera FPS and detection rates
+- Storage usage and trends
+- Event counts by camera
+- System temperatures
+
+A sample Grafana dashboard JSON will be provided in a future update.
+
+## Metric Types
+
+The metrics exposed by Frigate use the following Prometheus metric types:
+
+- **Counter**: Cumulative values that only increase (e.g., `frigate_camera_events`)
+- **Gauge**: Values that can go up and down (e.g., `frigate_cpu_usage_percent`)
+- **Info**: Key-value pairs for metadata (e.g., `frigate_storage_mount_type`)
+
+For more information about Prometheus metric types, see the [Prometheus documentation](https://prometheus.io/docs/concepts/metric_types/).

docs/sidebars.ts

@@ -22,6 +22,7 @@ const sidebars: SidebarsConfig = {
     Configuration: {
       'Configuration Files': [
         'configuration/index',
+        'configuration/metrics',
         'configuration/reference',
         {
           type: 'link',