feat(prometheus): add metrics to Subsonic API and Plugins (#4266)

* Add prometheus metrics to subsonic and plugins

* address feedback, do not log error if operation is not supported

* add missing timestamp and client to stats

* remove .view from subsonic route

* directly inject DataStore in Prometheus, to avoid having to pass it in every call

Signed-off-by: Deluan <deluan@navidrome.org>

---------

Signed-off-by: Deluan <deluan@navidrome.org>
Co-authored-by: Deluan <deluan@navidrome.org>

cmd/wire_gen.go

@@ -67,7 +67,8 @@ func CreateSubsonicAPIRouter(ctx context.Context) *subsonic.Router {
 	dataStore := persistence.New(sqlDB)
 	fileCache := artwork.GetImageCache()
 	fFmpeg := ffmpeg.New()
-	manager := plugins.GetManager(dataStore)
+	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
+	manager := plugins.GetManager(dataStore, metricsMetrics)
 	agentsAgents := agents.GetAgents(dataStore, manager)
 	provider := external.NewProvider(dataStore, agentsAgents)
 	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, fFmpeg, provider)
@@ -79,11 +80,10 @@ func CreateSubsonicAPIRouter(ctx context.Context) *subsonic.Router {
 	cacheWarmer := artwork.NewCacheWarmer(artworkArtwork, fileCache)
 	broker := events.GetBroker()
 	playlists := core.NewPlaylists(dataStore)
-	metricsMetrics := metrics.NewPrometheusInstance(dataStore)
 	scannerScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
 	playTracker := scrobbler.GetPlayTracker(dataStore, broker, manager)
 	playbackServer := playback.GetInstance(dataStore)
-	router := subsonic.New(dataStore, artworkArtwork, mediaStreamer, archiver, players, provider, scannerScanner, broker, playlists, playTracker, share, playbackServer)
+	router := subsonic.New(dataStore, artworkArtwork, mediaStreamer, archiver, players, provider, scannerScanner, broker, playlists, playTracker, share, playbackServer, metricsMetrics)
 	return router
 }
 
@@ -92,7 +92,8 @@ func CreatePublicRouter() *public.Router {
 	dataStore := persistence.New(sqlDB)
 	fileCache := artwork.GetImageCache()
 	fFmpeg := ffmpeg.New()
-	manager := plugins.GetManager(dataStore)
+	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
+	manager := plugins.GetManager(dataStore, metricsMetrics)
 	agentsAgents := agents.GetAgents(dataStore, manager)
 	provider := external.NewProvider(dataStore, agentsAgents)
 	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, fFmpeg, provider)
@@ -128,7 +129,7 @@ func CreateInsights() metrics.Insights {
 func CreatePrometheus() metrics.Metrics {
 	sqlDB := db.Db()
 	dataStore := persistence.New(sqlDB)
-	metricsMetrics := metrics.NewPrometheusInstance(dataStore)
+	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
 	return metricsMetrics
 }
 
@@ -137,14 +138,14 @@ func CreateScanner(ctx context.Context) scanner.Scanner {
 	dataStore := persistence.New(sqlDB)
 	fileCache := artwork.GetImageCache()
 	fFmpeg := ffmpeg.New()
-	manager := plugins.GetManager(dataStore)
+	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
+	manager := plugins.GetManager(dataStore, metricsMetrics)
 	agentsAgents := agents.GetAgents(dataStore, manager)
 	provider := external.NewProvider(dataStore, agentsAgents)
 	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, fFmpeg, provider)
 	cacheWarmer := artwork.NewCacheWarmer(artworkArtwork, fileCache)
 	broker := events.GetBroker()
 	playlists := core.NewPlaylists(dataStore)
-	metricsMetrics := metrics.NewPrometheusInstance(dataStore)
 	scannerScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
 	return scannerScanner
 }
@@ -154,14 +155,14 @@ func CreateScanWatcher(ctx context.Context) scanner.Watcher {
 	dataStore := persistence.New(sqlDB)
 	fileCache := artwork.GetImageCache()
 	fFmpeg := ffmpeg.New()
-	manager := plugins.GetManager(dataStore)
+	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
+	manager := plugins.GetManager(dataStore, metricsMetrics)
 	agentsAgents := agents.GetAgents(dataStore, manager)
 	provider := external.NewProvider(dataStore, agentsAgents)
 	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, fFmpeg, provider)
 	cacheWarmer := artwork.NewCacheWarmer(artworkArtwork, fileCache)
 	broker := events.GetBroker()
 	playlists := core.NewPlaylists(dataStore)
-	metricsMetrics := metrics.NewPrometheusInstance(dataStore)
 	scannerScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
 	watcher := scanner.NewWatcher(dataStore, scannerScanner)
 	return watcher
@@ -177,13 +178,14 @@ func GetPlaybackServer() playback.PlaybackServer {
 func getPluginManager() *plugins.Manager {
 	sqlDB := db.Db()
 	dataStore := persistence.New(sqlDB)
-	manager := plugins.GetManager(dataStore)
+	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
+	manager := plugins.GetManager(dataStore, metricsMetrics)
 	return manager
 }
 
 // wire_injectors.go:
 
-var allProviders = wire.NewSet(core.Set, artwork.Set, server.New, subsonic.New, nativeapi.New, public.New, persistence.New, lastfm.NewRouter, listenbrainz.NewRouter, events.GetBroker, scanner.New, scanner.NewWatcher, plugins.GetManager, metrics.NewPrometheusInstance, db.Db, wire.Bind(new(agents.PluginLoader), new(*plugins.Manager)), wire.Bind(new(scrobbler.PluginLoader), new(*plugins.Manager)))
+var allProviders = wire.NewSet(core.Set, artwork.Set, server.New, subsonic.New, nativeapi.New, public.New, persistence.New, lastfm.NewRouter, listenbrainz.NewRouter, events.GetBroker, scanner.New, scanner.NewWatcher, plugins.GetManager, metrics.GetPrometheusInstance, db.Db, wire.Bind(new(agents.PluginLoader), new(*plugins.Manager)), wire.Bind(new(scrobbler.PluginLoader), new(*plugins.Manager)))
 
 func GetPluginManager(ctx context.Context) *plugins.Manager {
 	manager := getPluginManager()

cmd/wire_injectors.go

@@ -40,7 +40,7 @@ var allProviders = wire.NewSet(
 	scanner.New,
 	scanner.NewWatcher,
 	plugins.GetManager,
-	metrics.NewPrometheusInstance,
+	metrics.GetPrometheusInstance,
 	db.Db,
 	wire.Bind(new(agents.PluginLoader), new(*plugins.Manager)),
 	wire.Bind(new(scrobbler.PluginLoader), new(*plugins.Manager)),

core/metrics/prometheus.go

@@ -2,7 +2,6 @@ package metrics
 
 import (
 	"context"
-	"fmt"
 	"net/http"
 	"strconv"
 	"sync"
@@ -13,6 +12,7 @@ import (
 	"github.com/navidrome/navidrome/consts"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/utils/singleton"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
@@ -20,6 +20,8 @@ import (
 type Metrics interface {
 	WriteInitialMetrics(ctx context.Context)
 	WriteAfterScanMetrics(ctx context.Context, success bool)
+	RecordRequest(ctx context.Context, endpoint, method, client string, status int, elapsed int64)
+	RecordPluginRequest(ctx context.Context, plugin, method string, ok bool, elapsed int64)
 	GetHandler() http.Handler
 }
 
@@ -27,11 +29,14 @@ type metrics struct {
 	ds model.DataStore
 }
 
-func NewPrometheusInstance(ds model.DataStore) Metrics {
+func GetPrometheusInstance(ds model.DataStore) Metrics {
-	if conf.Server.Prometheus.Enabled {
+	if !conf.Server.Prometheus.Enabled {
-		return &metrics{ds: ds}
+		return noopMetrics{}
 	}
-	return noopMetrics{}
+
+	return singleton.GetInstance(func() *metrics {
+		return &metrics{ds: ds}
+	})
 }
 
 func NewNoopInstance() Metrics {
@@ -51,6 +56,38 @@ func (m *metrics) WriteAfterScanMetrics(ctx context.Context, success bool) {
 	getPrometheusMetrics().mediaScansCounter.With(scanLabels).Inc()
 }
 
+func (m *metrics) RecordRequest(_ context.Context, endpoint, method, client string, status int, elapsed int64) {
+	httpLabel := prometheus.Labels{
+		"endpoint": endpoint,
+		"method":   method,
+		"client":   client,
+		"status":   strconv.FormatInt(int64(status), 10),
+	}
+	getPrometheusMetrics().httpRequestCounter.With(httpLabel).Inc()
+
+	httpLatencyLabel := prometheus.Labels{
+		"endpoint": endpoint,
+		"method":   method,
+		"client":   client,
+	}
+	getPrometheusMetrics().httpRequestDuration.With(httpLatencyLabel).Observe(float64(elapsed))
+}
+
+func (m *metrics) RecordPluginRequest(_ context.Context, plugin, method string, ok bool, elapsed int64) {
+	pluginLabel := prometheus.Labels{
+		"plugin": plugin,
+		"method": method,
+		"ok":     strconv.FormatBool(ok),
+	}
+	getPrometheusMetrics().pluginRequestCounter.With(pluginLabel).Inc()
+
+	pluginLatencyLabel := prometheus.Labels{
+		"plugin": plugin,
+		"method": method,
+	}
+	getPrometheusMetrics().pluginRequestDuration.With(pluginLatencyLabel).Observe(float64(elapsed))
+}
+
 func (m *metrics) GetHandler() http.Handler {
 	r := chi.NewRouter()
 
@@ -59,20 +96,31 @@ func (m *metrics) GetHandler() http.Handler {
 			consts.PrometheusAuthUser: conf.Server.Prometheus.Password,
 		}))
 	}
-	r.Handle("/", promhttp.Handler())
 
+	// Enable created at timestamp to handle zero counter on create.
+	// This requires --enable-feature=created-timestamp-zero-ingestion to be passed in Prometheus
+	r.Handle("/", promhttp.HandlerFor(prometheus.DefaultGatherer, promhttp.HandlerOpts{
+		EnableOpenMetrics:                   true,
+		EnableOpenMetricsTextCreatedSamples: true,
+	}))
 	return r
 }
 
 type prometheusMetrics struct {
-	dbTotal           *prometheus.GaugeVec
+	dbTotal               *prometheus.GaugeVec
-	versionInfo       *prometheus.GaugeVec
+	versionInfo           *prometheus.GaugeVec
-	lastMediaScan     *prometheus.GaugeVec
+	lastMediaScan         *prometheus.GaugeVec
-	mediaScansCounter *prometheus.CounterVec
+	mediaScansCounter     *prometheus.CounterVec
+	httpRequestCounter    *prometheus.CounterVec
+	httpRequestDuration   *prometheus.SummaryVec
+	pluginRequestCounter  *prometheus.CounterVec
+	pluginRequestDuration *prometheus.SummaryVec
 }
 
 // Prometheus' metrics requires initialization. But not more than once
 var getPrometheusMetrics = sync.OnceValue(func() *prometheusMetrics {
+	quartilesToEstimate := map[float64]float64{0.5: 0.05, 0.75: 0.025, 0.9: 0.01, 0.99: 0.001}
+
 	instance := &prometheusMetrics{
 		dbTotal: prometheus.NewGaugeVec(
 			prometheus.GaugeOpts{
@@ -102,23 +150,49 @@ var getPrometheusMetrics = sync.OnceValue(func() *prometheusMetrics {
 			},
 			[]string{"success"},
 		),
+		httpRequestCounter: prometheus.NewCounterVec(
+			prometheus.CounterOpts{
+				Name: "http_request_count",
+				Help: "Request types by status",
+			},
+			[]string{"endpoint", "method", "client", "status"},
+		),
+		httpRequestDuration: prometheus.NewSummaryVec(
+			prometheus.SummaryOpts{
+				Name:       "http_request_latency",
+				Help:       "Latency (in ms) of HTTP requests",
+				Objectives: quartilesToEstimate,
+			},
+			[]string{"endpoint", "method", "client"},
+		),
+		pluginRequestCounter: prometheus.NewCounterVec(
+			prometheus.CounterOpts{
+				Name: "plugin_request_count",
+				Help: "Plugin requests by method/status",
+			},
+			[]string{"plugin", "method", "ok"},
+		),
+		pluginRequestDuration: prometheus.NewSummaryVec(
+			prometheus.SummaryOpts{
+				Name:       "plugin_request_latency",
+				Help:       "Latency (in ms) of plugin requests",
+				Objectives: quartilesToEstimate,
+			},
+			[]string{"plugin", "method"},
+		),
 	}
-	err := prometheus.DefaultRegisterer.Register(instance.dbTotal)
+
-	if err != nil {
+	prometheus.DefaultRegisterer.MustRegister(
-		log.Fatal("Unable to create Prometheus metric instance", fmt.Errorf("unable to register db_model_totals metrics: %w", err))
+		instance.dbTotal,
-	}
+		instance.versionInfo,
-	err = prometheus.DefaultRegisterer.Register(instance.versionInfo)
+		instance.lastMediaScan,
-	if err != nil {
+		instance.mediaScansCounter,
-		log.Fatal("Unable to create Prometheus metric instance", fmt.Errorf("unable to register navidrome_info metrics: %w", err))
+		instance.httpRequestCounter,
-	}
+		instance.httpRequestDuration,
-	err = prometheus.DefaultRegisterer.Register(instance.lastMediaScan)
+		instance.pluginRequestCounter,
-	if err != nil {
+		instance.pluginRequestDuration,
-		log.Fatal("Unable to create Prometheus metric instance", fmt.Errorf("unable to register media_scan_last metrics: %w", err))
+	)
-	}
+
-	err = prometheus.DefaultRegisterer.Register(instance.mediaScansCounter)
-	if err != nil {
-		log.Fatal("Unable to create Prometheus metric instance", fmt.Errorf("unable to register media_scans metrics: %w", err))
-	}
 	return instance
 })
 
@@ -159,4 +233,8 @@ func (n noopMetrics) WriteInitialMetrics(context.Context) {}
 
 func (n noopMetrics) WriteAfterScanMetrics(context.Context, bool) {}
 
+func (n noopMetrics) RecordRequest(context.Context, string, string, string, int, int64) {}
+
+func (n noopMetrics) RecordPluginRequest(context.Context, string, string, bool, int64) {}
+
 func (n noopMetrics) GetHandler() http.Handler { return nil }

plugins/adapter_media_agent.go

@@ -10,22 +10,23 @@ import (
 )
 
 // NewWasmMediaAgent creates a new adapter for a MetadataAgent plugin
-func newWasmMediaAgent(wasmPath, pluginID string, runtime api.WazeroNewRuntime, mc wazero.ModuleConfig) WasmPlugin {
+func newWasmMediaAgent(wasmPath, pluginID string, m *Manager, runtime api.WazeroNewRuntime, mc wazero.ModuleConfig) WasmPlugin {
 	loader, err := api.NewMetadataAgentPlugin(context.Background(), api.WazeroRuntime(runtime), api.WazeroModuleConfig(mc))
 	if err != nil {
 		log.Error("Error creating media metadata service plugin", "plugin", pluginID, "path", wasmPath, err)
 		return nil
 	}
 	return &wasmMediaAgent{
-		wasmBasePlugin: &wasmBasePlugin[api.MetadataAgent, *api.MetadataAgentPlugin]{
+		wasmBasePlugin: newWasmBasePlugin[api.MetadataAgent, *api.MetadataAgentPlugin](
-			wasmPath:   wasmPath,
+			wasmPath,
-			id:         pluginID,
+			pluginID,
-			capability: CapabilityMetadataAgent,
+			CapabilityMetadataAgent,
-			loader:     loader,
+			m.metrics,
-			loadFunc: func(ctx context.Context, l *api.MetadataAgentPlugin, path string) (api.MetadataAgent, error) {
+			loader,
+			func(ctx context.Context, l *api.MetadataAgentPlugin, path string) (api.MetadataAgent, error) {
 				return l.Load(ctx, path)
 			},
-		},
+		),
 	}
 }
 

plugins/adapter_media_agent_test.go

@@ -23,7 +23,7 @@ var _ = Describe("Adapter Media Agent", func() {
 		DeferCleanup(configtest.SetupConfig())
 		conf.Server.Plugins.Folder = testDataDir
 
-		mgr = createManager(nil)
+		mgr = createManager(nil, nil)
 		mgr.ScanPlugins()
 	})
 

plugins/adapter_scheduler_callback.go

@@ -9,22 +9,23 @@ import (
 )
 
 // newWasmSchedulerCallback creates a new adapter for a SchedulerCallback plugin
-func newWasmSchedulerCallback(wasmPath, pluginID string, runtime api.WazeroNewRuntime, mc wazero.ModuleConfig) WasmPlugin {
+func newWasmSchedulerCallback(wasmPath, pluginID string, m *Manager, runtime api.WazeroNewRuntime, mc wazero.ModuleConfig) WasmPlugin {
 	loader, err := api.NewSchedulerCallbackPlugin(context.Background(), api.WazeroRuntime(runtime), api.WazeroModuleConfig(mc))
 	if err != nil {
 		log.Error("Error creating scheduler callback plugin", "plugin", pluginID, "path", wasmPath, err)
 		return nil
 	}
 	return &wasmSchedulerCallback{
-		wasmBasePlugin: &wasmBasePlugin[api.SchedulerCallback, *api.SchedulerCallbackPlugin]{
+		wasmBasePlugin: newWasmBasePlugin[api.SchedulerCallback, *api.SchedulerCallbackPlugin](
-			wasmPath:   wasmPath,
+			wasmPath,
-			id:         pluginID,
+			pluginID,
-			capability: CapabilitySchedulerCallback,
+			CapabilitySchedulerCallback,
-			loader:     loader,
+			m.metrics,
-			loadFunc: func(ctx context.Context, l *api.SchedulerCallbackPlugin, path string) (api.SchedulerCallback, error) {
+			loader,
+			func(ctx context.Context, l *api.SchedulerCallbackPlugin, path string) (api.SchedulerCallback, error) {
 				return l.Load(ctx, path)
 			},
-		},
+		),
 	}
 }
 

plugins/adapter_scrobbler.go

@@ -12,22 +12,23 @@ import (
 	"github.com/tetratelabs/wazero"
 )
 
-func newWasmScrobblerPlugin(wasmPath, pluginID string, runtime api.WazeroNewRuntime, mc wazero.ModuleConfig) WasmPlugin {
+func newWasmScrobblerPlugin(wasmPath, pluginID string, m *Manager, runtime api.WazeroNewRuntime, mc wazero.ModuleConfig) WasmPlugin {
 	loader, err := api.NewScrobblerPlugin(context.Background(), api.WazeroRuntime(runtime), api.WazeroModuleConfig(mc))
 	if err != nil {
 		log.Error("Error creating scrobbler service plugin", "plugin", pluginID, "path", wasmPath, err)
 		return nil
 	}
 	return &wasmScrobblerPlugin{
-		wasmBasePlugin: &wasmBasePlugin[api.Scrobbler, *api.ScrobblerPlugin]{
+		wasmBasePlugin: newWasmBasePlugin[api.Scrobbler, *api.ScrobblerPlugin](
-			wasmPath:   wasmPath,
+			wasmPath,
-			id:         pluginID,
+			pluginID,
-			capability: CapabilityScrobbler,
+			CapabilityScrobbler,
-			loader:     loader,
+			m.metrics,
-			loadFunc: func(ctx context.Context, l *api.ScrobblerPlugin, path string) (api.Scrobbler, error) {
+			loader,
+			func(ctx context.Context, l *api.ScrobblerPlugin, path string) (api.Scrobbler, error) {
 				return l.Load(ctx, path)
 			},
-		},
+		),
 	}
 }
 

plugins/adapter_websocket_callback.go

@@ -9,22 +9,23 @@ import (
 )
 
 // newWasmWebSocketCallback creates a new adapter for a WebSocketCallback plugin
-func newWasmWebSocketCallback(wasmPath, pluginID string, runtime api.WazeroNewRuntime, mc wazero.ModuleConfig) WasmPlugin {
+func newWasmWebSocketCallback(wasmPath, pluginID string, m *Manager, runtime api.WazeroNewRuntime, mc wazero.ModuleConfig) WasmPlugin {
 	loader, err := api.NewWebSocketCallbackPlugin(context.Background(), api.WazeroRuntime(runtime), api.WazeroModuleConfig(mc))
 	if err != nil {
 		log.Error("Error creating WebSocket callback plugin", "plugin", pluginID, "path", wasmPath, err)
 		return nil
 	}
 	return &wasmWebSocketCallback{
-		wasmBasePlugin: &wasmBasePlugin[api.WebSocketCallback, *api.WebSocketCallbackPlugin]{
+		wasmBasePlugin: newWasmBasePlugin[api.WebSocketCallback, *api.WebSocketCallbackPlugin](
-			wasmPath:   wasmPath,
+			wasmPath,
-			id:         pluginID,
+			pluginID,
-			capability: CapabilityWebSocketCallback,
+			CapabilityWebSocketCallback,
-			loader:     loader,
+			m.metrics,
-			loadFunc: func(ctx context.Context, l *api.WebSocketCallbackPlugin, path string) (api.WebSocketCallback, error) {
+			loader,
+			func(ctx context.Context, l *api.WebSocketCallbackPlugin, path string) (api.WebSocketCallback, error) {
 				return l.Load(ctx, path)
 			},
-		},
+		),
 	}
 }
 

plugins/host_scheduler_test.go

@@ -16,7 +16,7 @@ var _ = Describe("SchedulerService", func() {
 	)
 
 	BeforeEach(func() {
-		manager = createManager(nil)
+		manager = createManager(nil, nil)
 		ss = manager.schedulerService
 	})
 

plugins/host_websocket_test.go

@@ -84,7 +84,7 @@ var _ = Describe("WebSocket Host Service", func() {
 		DeferCleanup(server.Close)
 
 		// Create a new manager and websocket service
-		manager = createManager(nil)
+		manager = createManager(nil, nil)
 		wsService = newWebsocketService(manager)
 	})
 

plugins/manager.go

@@ -20,6 +20,7 @@ import (
 
 	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/core/agents"
+	"github.com/navidrome/navidrome/core/metrics"
 	"github.com/navidrome/navidrome/core/scrobbler"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
@@ -39,7 +40,7 @@ const (
 )
 
 // pluginCreators maps capability types to their respective creator functions
-type pluginConstructor func(wasmPath, pluginID string, runtime api.WazeroNewRuntime, mc wazero.ModuleConfig) WasmPlugin
+type pluginConstructor func(wasmPath, pluginID string, m *Manager, runtime api.WazeroNewRuntime, mc wazero.ModuleConfig) WasmPlugin
 
 var pluginCreators = map[string]pluginConstructor{
 	CapabilityMetadataAgent:     newWasmMediaAgent,
@@ -95,21 +96,23 @@ type Manager struct {
 	lifecycle        *pluginLifecycleManager        // Manages plugin lifecycle and initialization
 	adapters         map[string]WasmPlugin          // Map of plugin folder name + capability to adapter
 	ds               model.DataStore                // DataStore for accessing persistent data
+	metrics          metrics.Metrics
 }
 
 // GetManager returns the singleton instance of Manager
-func GetManager(ds model.DataStore) *Manager {
+func GetManager(ds model.DataStore, metrics metrics.Metrics) *Manager {
 	return singleton.GetInstance(func() *Manager {
-		return createManager(ds)
+		return createManager(ds, metrics)
 	})
 }
 
 // createManager creates a new Manager instance. Used in tests
-func createManager(ds model.DataStore) *Manager {
+func createManager(ds model.DataStore, metrics metrics.Metrics) *Manager {
 	m := &Manager{
 		plugins:   make(map[string]*plugin),
 		lifecycle: newPluginLifecycleManager(),
 		ds:        ds,
+		metrics:   metrics,
 	}
 
 	// Create the host services
@@ -174,7 +177,7 @@ func (m *Manager) registerPlugin(pluginID, pluginDir, wasmPath string, manifest
 			}
 			continue
 		}
-		adapter := constructor(wasmPath, pluginID, customRuntime, mc)
+		adapter := constructor(wasmPath, pluginID, m, customRuntime, mc)
 		if adapter == nil {
 			log.Error("Failed to create plugin adapter", "plugin", pluginID, "capability", capabilityStr, "path", wasmPath)
 			continue

plugins/manager_test.go

@@ -27,7 +27,7 @@ var _ = Describe("Plugin Manager", func() {
 		conf.Server.Plugins.Folder = testDataDir
 
 		ctx = GinkgoT().Context()
-		mgr = createManager(nil)
+		mgr = createManager(nil, nil)
 		mgr.ScanPlugins()
 	})
 
@@ -85,7 +85,7 @@ var _ = Describe("Plugin Manager", func() {
 			})
 
 			conf.Server.Plugins.Folder = tempPluginsDir
-			m = createManager(nil)
+			m = createManager(nil, nil)
 		})
 
 		// Helper to create a complete valid plugin for manager testing

plugins/manifest_permissions_test.go

@@ -55,7 +55,7 @@ var _ = Describe("Plugin Permissions", func() {
 	BeforeEach(func() {
 		DeferCleanup(configtest.SetupConfig())
 		ctx = context.Background()
-		mgr = createManager(nil)
+		mgr = createManager(nil, nil)
 		tempDir = GinkgoT().TempDir()
 	})
 

plugins/runtime_test.go

@@ -40,7 +40,7 @@ var _ = Describe("CachingRuntime", func() {
 
 	BeforeEach(func() {
 		ctx = GinkgoT().Context()
-		mgr = createManager(nil)
+		mgr = createManager(nil, nil)
 		// Add permissions for the test plugin using typed struct
 		permissions := schema.PluginManifestPermissions{
 			Http: &schema.PluginManifestPermissionsHttp{
@@ -58,6 +58,7 @@ var _ = Describe("CachingRuntime", func() {
 		plugin = newWasmScrobblerPlugin(
 			filepath.Join(testDataDir, "fake_scrobbler", "plugin.wasm"),
 			"fake_scrobbler",
+			mgr,
 			rtFunc,
 			wazero.NewModuleConfig().WithStartFunctions("_initialize"),
 		).(*wasmScrobblerPlugin)

plugins/wasm_base_plugin.go

@@ -2,13 +2,28 @@ package plugins
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"time"
 
+	"github.com/navidrome/navidrome/core/agents"
+	"github.com/navidrome/navidrome/core/metrics"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model/id"
 )
 
+// newWasmBasePlugin creates a new instance of wasmBasePlugin with the required parameters.
+func newWasmBasePlugin[S any, P any](wasmPath, id, capability string, m metrics.Metrics, loader P, loadFunc loaderFunc[S, P]) *wasmBasePlugin[S, P] {
+	return &wasmBasePlugin[S, P]{
+		wasmPath:   wasmPath,
+		id:         id,
+		capability: capability,
+		loader:     loader,
+		loadFunc:   loadFunc,
+		metrics:    m,
+	}
+}
+
 // LoaderFunc is a generic function type that loads a plugin instance.
 type loaderFunc[S any, P any] func(ctx context.Context, loader P, path string) (S, error)
 
@@ -20,6 +35,7 @@ type wasmBasePlugin[S any, P any] struct {
 	capability string
 	loader     P
 	loadFunc   loaderFunc[S, P]
+	metrics    metrics.Metrics
 }
 
 func (w *wasmBasePlugin[S, P]) PluginID() string {
@@ -34,6 +50,10 @@ func (w *wasmBasePlugin[S, P]) serviceName() string {
 	return w.id + "_" + w.capability
 }
 
+func (w *wasmBasePlugin[S, P]) getMetrics() metrics.Metrics {
+	return w.metrics
+}
+
 // getInstance loads a new plugin instance and returns a cleanup function.
 func (w *wasmBasePlugin[S, P]) getInstance(ctx context.Context, methodName string) (S, func(), error) {
 	start := time.Now()
@@ -57,7 +77,9 @@ func (w *wasmBasePlugin[S, P]) getInstance(ctx context.Context, methodName strin
 }
 
 type wasmPlugin[S any] interface {
+	PluginID() string
 	getInstance(ctx context.Context, methodName string) (S, func(), error)
+	getMetrics() metrics.Metrics
 }
 
 type errorMapper interface {
@@ -73,10 +95,25 @@ func callMethod[S any, R any](ctx context.Context, w wasmPlugin[S], methodName s
 	if err != nil {
 		return r, err
 	}
+	start := time.Now()
 	defer done()
 	r, err = fn(inst)
+	elapsed := time.Since(start)
+
 	if em, ok := any(w).(errorMapper); ok {
-		return r, em.mapError(err)
+		mappedErr := em.mapError(err)
+
+		if !errors.Is(mappedErr, agents.ErrNotFound) {
+			id := w.PluginID()
+			isOk := mappedErr == nil
+			metrics := w.getMetrics()
+			if metrics != nil {
+				metrics.RecordPluginRequest(ctx, id, methodName, isOk, elapsed.Milliseconds())
+			}
+			log.Trace(ctx, "callMethod", "plugin", id, "method", methodName, "ok", isOk, elapsed)
+		}
+
+		return r, mappedErr
 	}
 	return r, err
 }

server/subsonic/album_lists_test.go

@@ -25,7 +25,7 @@ var _ = Describe("Album Lists", func() {
 	BeforeEach(func() {
 		ds = &tests.MockDataStore{}
 		mockRepo = ds.Album(ctx).(*tests.MockAlbumRepo)
-		router = New(ds, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil)
+		router = New(ds, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil)
 		w = httptest.NewRecorder()
 	})
 

server/subsonic/api.go

@@ -13,6 +13,7 @@ import (
 	"github.com/navidrome/navidrome/core"
 	"github.com/navidrome/navidrome/core/artwork"
 	"github.com/navidrome/navidrome/core/external"
+	"github.com/navidrome/navidrome/core/metrics"
 	"github.com/navidrome/navidrome/core/playback"
 	"github.com/navidrome/navidrome/core/scrobbler"
 	"github.com/navidrome/navidrome/log"
@@ -43,11 +44,13 @@ type Router struct {
 	scrobbler scrobbler.PlayTracker
 	share     core.Share
 	playback  playback.PlaybackServer
+	metrics   metrics.Metrics
 }
 
 func New(ds model.DataStore, artwork artwork.Artwork, streamer core.MediaStreamer, archiver core.Archiver,
 	players core.Players, provider external.Provider, scanner scanner.Scanner, broker events.Broker,
 	playlists core.Playlists, scrobbler scrobbler.PlayTracker, share core.Share, playback playback.PlaybackServer,
+	metrics metrics.Metrics,
 ) *Router {
 	r := &Router{
 		ds:        ds,
@@ -62,6 +65,7 @@ func New(ds model.DataStore, artwork artwork.Artwork, streamer core.MediaStreame
 		scrobbler: scrobbler,
 		share:     share,
 		playback:  playback,
+		metrics:   metrics,
 	}
 	r.Handler = r.routes()
 	return r
@@ -69,6 +73,11 @@ func New(ds model.DataStore, artwork artwork.Artwork, streamer core.MediaStreame
 
 func (api *Router) routes() http.Handler {
 	r := chi.NewRouter()
+
+	if conf.Server.Prometheus.Enabled {
+		r.Use(recordStats(api.metrics))
+	}
+
 	r.Use(postFormToQueryParams)
 
 	// Public
@@ -223,7 +232,7 @@ func h(r chi.Router, path string, f handler) {
 	})
 }
 
-// Add a Subsonic handler that requires a http.ResponseWriter (ex: stream, getCoverArt...)
+// Add a Subsonic handler that requires an http.ResponseWriter (ex: stream, getCoverArt...)
 func hr(r chi.Router, path string, f handlerRaw) {
 	handle := func(w http.ResponseWriter, r *http.Request) {
 		res, err := f(w, r)

server/subsonic/media_annotation_test.go

@@ -27,7 +27,7 @@ var _ = Describe("MediaAnnotationController", func() {
 		ds = &tests.MockDataStore{}
 		playTracker = &fakePlayTracker{}
 		eventBroker = &fakeEventBroker{}
-		router = New(ds, nil, nil, nil, nil, nil, nil, eventBroker, nil, playTracker, nil, nil)
+		router = New(ds, nil, nil, nil, nil, nil, nil, eventBroker, nil, playTracker, nil, nil, nil)
 	})
 
 	Describe("Scrobble", func() {

server/subsonic/media_retrieval_test.go

@@ -33,7 +33,7 @@ var _ = Describe("MediaRetrievalController", func() {
 			MockedMediaFile: mockRepo,
 		}
 		artwork = &fakeArtwork{data: "image data"}
-		router = New(ds, artwork, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil)
+		router = New(ds, artwork, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil)
 		w = httptest.NewRecorder()
 		DeferCleanup(configtest.SetupConfig())
 		conf.Server.LyricsPriority = "embedded,.lrc"

server/subsonic/middlewares.go

@@ -11,12 +11,15 @@ import (
 	"net/http"
 	"net/url"
 	"strings"
+	"time"
 
+	"github.com/go-chi/chi/v5/middleware"
 	ua "github.com/mileusna/useragent"
 	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/consts"
 	"github.com/navidrome/navidrome/core"
 	"github.com/navidrome/navidrome/core/auth"
+	"github.com/navidrome/navidrome/core/metrics"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/model/request"
@@ -222,3 +225,23 @@ func playerIDCookieName(userName string) string {
 	cookieName := fmt.Sprintf("nd-player-%x", userName)
 	return cookieName
 }
+
+func recordStats(metrics metrics.Metrics) func(next http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		fn := func(w http.ResponseWriter, r *http.Request) {
+			ww := middleware.NewWrapResponseWriter(w, r.ProtoMajor)
+
+			start := time.Now()
+			defer func() {
+				// We want to get the client name (even if not present for certain endpoints)
+				p := req.Params(r)
+				client, _ := p.String("c")
+
+				metrics.RecordRequest(r.Context(), strings.Replace(r.URL.Path, ".view", "", 1), r.Method, client, ww.Status(), time.Since(start).Milliseconds())
+			}()
+
+			next.ServeHTTP(ww, r)
+		}
+		return http.HandlerFunc(fn)
+	}
+}

server/subsonic/opensubsonic_test.go

@@ -19,7 +19,7 @@ var _ = Describe("GetOpenSubsonicExtensions", func() {
 	)
 
 	BeforeEach(func() {
-		router = subsonic.New(nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil)
+		router = subsonic.New(nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil)
 		w = httptest.NewRecorder()
 		r = httptest.NewRequest("GET", "/getOpenSubsonicExtensions?f=json", nil)
 	})

server/subsonic/playlists_test.go

@@ -20,7 +20,7 @@ var _ = Describe("UpdatePlaylist", func() {
 	BeforeEach(func() {
 		ds = &tests.MockDataStore{}
 		playlists = &fakePlaylists{}
-		router = New(ds, nil, nil, nil, nil, nil, nil, nil, playlists, nil, nil, nil)
+		router = New(ds, nil, nil, nil, nil, nil, nil, nil, playlists, nil, nil, nil, nil)
 	})
 
 	It("clears the comment when parameter is empty", func() {