Move Prom metrics to a dedicated port + improve Helm chart (#599)

internal/web/handlers/metrics/metrics.go

@@ -1,16 +1,12 @@
 package metrics
 
 import (
-	"github.com/labstack/echo-contrib/echoprometheus"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
-	"github.com/thomiceli/opengist/internal/config"
 	"github.com/thomiceli/opengist/internal/db"
-	"github.com/thomiceli/opengist/internal/web/context"
 )
 
 var (
-	// Using promauto to automatically register metrics with the default registry
 	countUsersGauge   prometheus.Gauge
 	countGistsGauge   prometheus.Gauge
 	countSSHKeysGauge prometheus.Gauge
@@ -18,84 +14,52 @@ var (
 	metricsInitialized bool = false
 )
 
-// initMetrics initializes metrics if they're not already initialized
 func initMetrics() {
 	if metricsInitialized {
 		return
 	}
 
-	// Only initialize metrics if they're enabled
-	if config.C.MetricsEnabled {
-		countUsersGauge = promauto.NewGauge(
-			prometheus.GaugeOpts{
-				Name: "opengist_users_total",
-				Help: "Total number of users",
-			},
-		)
+	countUsersGauge = promauto.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "opengist_users_total",
+			Help: "Total number of users",
+		},
+	)
 
-		countGistsGauge = promauto.NewGauge(
-			prometheus.GaugeOpts{
-				Name: "opengist_gists_total",
-				Help: "Total number of gists",
-			},
-		)
+	countGistsGauge = promauto.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "opengist_gists_total",
+			Help: "Total number of gists",
+		},
+	)
 
-		countSSHKeysGauge = promauto.NewGauge(
-			prometheus.GaugeOpts{
-				Name: "opengist_ssh_keys_total",
-				Help: "Total number of SSH keys",
-			},
-		)
+	countSSHKeysGauge = promauto.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "opengist_ssh_keys_total",
+			Help: "Total number of SSH keys",
+		},
+	)
 
-		metricsInitialized = true
-	}
+	metricsInitialized = true
 }
 
-// updateMetrics refreshes all metric values from the database
 func updateMetrics() {
-	// Only update metrics if they're enabled
-	if !config.C.MetricsEnabled || !metricsInitialized {
+	if !metricsInitialized {
 		return
 	}
 
-	// Update users count
 	countUsers, err := db.CountAll(&db.User{})
 	if err == nil {
 		countUsersGauge.Set(float64(countUsers))
 	}
 
-	// Update gists count
 	countGists, err := db.CountAll(&db.Gist{})
 	if err == nil {
 		countGistsGauge.Set(float64(countGists))
 	}
 
-	// Update SSH keys count
 	countKeys, err := db.CountAll(&db.SSHKey{})
 	if err == nil {
 		countSSHKeysGauge.Set(float64(countKeys))
 	}
 }
-
-// Metrics handles prometheus metrics endpoint requests.
-func Metrics(ctx *context.Context) error {
-	// If metrics are disabled, return 404
-	if !config.C.MetricsEnabled {
-		return ctx.NotFound("Metrics endpoint is disabled")
-	}
-
-	// Initialize metrics if not already done
-	initMetrics()
-
-	// Update metrics
-	updateMetrics()
-
-	// Get the Echo context
-	echoCtx := ctx.Context
-
-	// Use the Prometheus metrics handler
-	handler := echoprometheus.NewHandler()
-
-	// Call the handler
-	return handler(echoCtx)
-}

internal/web/handlers/metrics/server.go

@@ -0,0 +1,50 @@
+package metrics
+
+import (
+	"net/http"
+
+	"github.com/labstack/echo-contrib/echoprometheus"
+	"github.com/labstack/echo/v4"
+	"github.com/rs/zerolog/log"
+	"github.com/thomiceli/opengist/internal/config"
+)
+
+type Server struct {
+	echo *echo.Echo
+}
+
+func NewServer() *Server {
+	e := echo.New()
+	e.HideBanner = true
+	e.HidePort = true
+
+	s := &Server{echo: e}
+
+	initMetrics()
+
+	e.GET("/metrics", func(ctx echo.Context) error {
+		updateMetrics()
+		return echoprometheus.NewHandler()(ctx)
+	})
+
+	return s
+}
+
+func (s *Server) Start() {
+	addr := config.C.MetricsHost + ":" + config.C.MetricsPort
+	log.Info().Msg("Starting metrics server on http://" + addr)
+	if err := s.echo.Start(addr); err != nil && err != http.ErrServerClosed {
+		log.Error().Err(err).Msg("Failed to start metrics server")
+	}
+}
+
+func (s *Server) Stop() {
+	log.Info().Msg("Stopping metrics server...")
+	if err := s.echo.Close(); err != nil {
+		log.Error().Err(err).Msg("Failed to stop metrics server")
+	}
+}
+
+func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	s.echo.ServeHTTP(w, r)
+}