refactor: add prometheus server package

cmd/start/cmd.go

@@ -1,8 +1,6 @@
 package start
 
 import (
-	"fmt"
-	"net/http"
 	"os"
 	"os/signal"
 	"sync"
@@ -18,7 +16,6 @@ import (
 	"github.com/forbole/juno/v5/types"
 	cmdtypes "github.com/forbole/juno/v5/types/cmd"
 	"github.com/forbole/juno/v5/utils"
-	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
 var (
@@ -61,12 +58,7 @@ func startParsing(ctx *parser.Context) error {
 	// Start the prometheus monitoring
 	monitoringCfg := ctx.Config.Monitoring
 	if monitoringCfg.Enabled {
-		http.Handle("/metrics", promhttp.Handler())
-		server := &http.Server{
-			Addr:              fmt.Sprintf(":%d", monitoringCfg.Port),
-			ReadHeaderTimeout: 3 * time.Second,
-		}
-		go server.ListenAndServe()
+		ctx.Prometheus.Start()
 	}
 
 	// Start periodic operations
@@ -234,5 +226,6 @@ func trapSignal(ctx *parser.Context) {
 		defer ctx.Node.Stop()
 		defer ctx.Database.Close()
 		defer waitGroup.Done()
+		defer ctx.Prometheus.Stop()
 	}()
 }

parser/context.go

@@ -5,6 +5,7 @@ import (
 	"github.com/forbole/juno/v5/logging"
 	"github.com/forbole/juno/v5/modules"
 	"github.com/forbole/juno/v5/node"
+	"github.com/forbole/juno/v5/prometheus"
 	"github.com/forbole/juno/v5/types"
 	"github.com/forbole/juno/v5/types/config"
 )
@@ -17,6 +18,7 @@ type Context struct {
 	Database       database.Database
 	Logger         logging.Logger
 	Modules        []modules.Module
+	Prometheus     *prometheus.Server
 }
 
 // NewContext builds a new Context instance
@@ -35,5 +37,6 @@ func NewContext(
 		Database:       db,
 		Modules:        modules,
 		Logger:         logger,
+		Prometheus:     prometheus.NewServer(config.Monitoring.Port),
 	}
 }

prometheus/server.go

@@ -0,0 +1,44 @@
+package prometheus
+
+import (
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+type Server struct {
+	port   int16
+	server *http.Server
+}
+
+// NewServer returns a new prometheus server instance
+func NewServer(port int16) *Server {
+	return &Server{
+		port: port,
+	}
+}
+
+// Start starts the prometheus server
+func (s *Server) Start() {
+	// Server already started
+	if s.server != nil {
+		return
+	}
+
+	http.Handle("/metrics", promhttp.Handler())
+	s.server = &http.Server{
+		Addr:              fmt.Sprintf(":%d", s.port),
+		ReadHeaderTimeout: 3 * time.Second,
+	}
+	go s.server.ListenAndServe()
+}
+
+// Stop stops the prometheus server
+func (s *Server) Stop() {
+	if s.server != nil {
+		s.server.Close()
+		s.server = nil
+	}
+}