Add Prometheus exporter

service/httpd/httpd.go

@@ -16,6 +16,7 @@ import (
 	"miniflux.app/api"
 	"miniflux.app/config"
 	"miniflux.app/fever"
+	"miniflux.app/http/request"
 	"miniflux.app/logger"
 	"miniflux.app/reader/feed"
 	"miniflux.app/storage"
@@ -24,6 +25,7 @@ import (
 	"miniflux.app/worker"
 
 	"github.com/gorilla/mux"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"golang.org/x/crypto/acme/autocert"
 )
 
@@ -186,9 +188,45 @@ func setupHandler(store *storage.Storage, feedHandler *feed.Handler, pool *worke
 	router.HandleFunc("/healthcheck", func(w http.ResponseWriter, r *http.Request) {
 		w.Write([]byte("OK"))
 	}).Name("healthcheck")
+
 	router.HandleFunc("/version", func(w http.ResponseWriter, r *http.Request) {
 		w.Write([]byte(version.Version))
 	}).Name("version")
 
+	if config.Opts.HasMetricsCollector() {
+		router.Handle("/metrics", promhttp.Handler()).Name("metrics")
+		router.Use(func(next http.Handler) http.Handler {
+			return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				route := mux.CurrentRoute(r)
+
+				// Returns a 404 if the client is not authorized to access the metrics endpoint.
+				if route.GetName() == "metrics" && !isAllowedToAccessMetricsEndpoint(r) {
+					logger.Error(`[Metrics] Client not allowed: %s`, request.ClientIP(r))
+					http.NotFound(w, r)
+					return
+				}
+
+				next.ServeHTTP(w, r)
+			})
+		})
+	}
+
 	return router
 }
+
+func isAllowedToAccessMetricsEndpoint(r *http.Request) bool {
+	clientIP := net.ParseIP(request.ClientIP(r))
+
+	for _, cidr := range config.Opts.MetricsAllowedNetworks() {
+		_, network, err := net.ParseCIDR(cidr)
+		if err != nil {
+			logger.Fatal(`[Metrics] Unable to parse CIDR %v`, err)
+		}
+
+		if network.Contains(clientIP) {
+			return true
+		}
+	}
+
+	return false
+}

service/scheduler/scheduler.go

@@ -9,6 +9,7 @@ import (
 
 	"miniflux.app/config"
 	"miniflux.app/logger"
+	"miniflux.app/metric"
 	"miniflux.app/model"
 	"miniflux.app/storage"
 	"miniflux.app/worker"
@@ -35,8 +36,7 @@ func Serve(store *storage.Storage, pool *worker.Pool) {
 }
 
 func feedScheduler(store *storage.Storage, pool *worker.Pool, frequency, batchSize int) {
-	c := time.Tick(time.Duration(frequency) * time.Minute)
-	for range c {
+	for range time.Tick(time.Duration(frequency) * time.Minute) {
 		jobs, err := store.NewBatch(batchSize)
 		if err != nil {
 			logger.Error("[Scheduler:Feed] %v", err)
@@ -48,22 +48,31 @@ func feedScheduler(store *storage.Storage, pool *worker.Pool, frequency, batchSi
 }
 
 func cleanupScheduler(store *storage.Storage, frequency, archiveReadDays, archiveUnreadDays, sessionsDays int) {
-	c := time.Tick(time.Duration(frequency) * time.Hour)
-	for range c {
+	for range time.Tick(time.Duration(frequency) * time.Hour) {
 		nbSessions := store.CleanOldSessions(sessionsDays)
 		nbUserSessions := store.CleanOldUserSessions(sessionsDays)
 		logger.Info("[Scheduler:Cleanup] Cleaned %d sessions and %d user sessions", nbSessions, nbUserSessions)
 
+		startTime := time.Now()
 		if rowsAffected, err := store.ArchiveEntries(model.EntryStatusRead, archiveReadDays); err != nil {
 			logger.Error("[Scheduler:ArchiveReadEntries] %v", err)
 		} else {
 			logger.Info("[Scheduler:ArchiveReadEntries] %d entries changed", rowsAffected)
+
+			if config.Opts.HasMetricsCollector() {
+				metric.ArchiveEntriesDuration.WithLabelValues(model.EntryStatusRead).Observe(time.Since(startTime).Seconds())
+			}
 		}
 
+		startTime = time.Now()
 		if rowsAffected, err := store.ArchiveEntries(model.EntryStatusUnread, archiveUnreadDays); err != nil {
 			logger.Error("[Scheduler:ArchiveUnreadEntries] %v", err)
 		} else {
 			logger.Info("[Scheduler:ArchiveUnreadEntries] %d entries changed", rowsAffected)
+
+			if config.Opts.HasMetricsCollector() {
+				metric.ArchiveEntriesDuration.WithLabelValues(model.EntryStatusUnread).Observe(time.Since(startTime).Seconds())
+			}
 		}
 	}
 }