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

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)
+}