From 9ab70156e715ceb5d306ef4e1f684933715559a4 Mon Sep 17 00:00:00 2001
From: Tommy Skaug <tom@252.no>
Date: Thu, 26 Sep 2024 05:54:52 +0200
Subject: [PATCH] chore: cleanup of code, logging and variables. This also
 fixes an issue with a copy-paste variable causing an error starting the
 metrics server.

---
 server/main.go      | 85 +++++++++------------------------------------
 server/wellknown.go |  2 --
 2 files changed, 17 insertions(+), 70 deletions(-)

diff --git a/server/main.go b/server/main.go
index e52955a..560a55c 100644
--- a/server/main.go
+++ b/server/main.go
@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	"flag"
+	"log"
 	"net/http"
 	"os"
 	"os/signal"
@@ -13,7 +14,6 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
-	log "github.com/sirupsen/logrus"
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/kubernetes"
@@ -27,15 +27,15 @@ import (
 )
 
 var (
-	kubeconfig     string
-	namespace      string
-	cmName         string
-	id             string
-	leaseLockName  string
-	leaderOverride bool
+	kubeconfig    string
+	namespace     string
+	cmName        string
+	id            string
+	leaseLockName string
 
-	serverPort string
-	healthPort string
+	serverPort  string
+	healthPort  string
+	metricsPort string
 
 	requestCounter = promauto.NewCounterVec(
 		prometheus.CounterOpts{
@@ -55,8 +55,6 @@ var (
 
 func parseFlags() {
 	klog.InitFlags(nil)
-	log.SetFormatter(&log.JSONFormatter{})
-	log.SetLevel(log.InfoLevel)
 
 	// Check for KUBECONFIG environment variable
 	if kubeconfigEnv := os.Getenv("KUBECONFIG"); kubeconfigEnv != "" {
@@ -72,7 +70,7 @@ func parseFlags() {
 	flag.StringVar(&leaseLockName, "lease-lock-name", "well-known", "the lease lock resource name")
 	flag.StringVar(&serverPort, "server-port", "8080", "server port")
 	flag.StringVar(&healthPort, "health-port", "8081", "health port")
-	flag.BoolVar(&leaderOverride, "leader-override", false, "manually override leader election")
+	flag.StringVar(&metricsPort, "metrics-port", "9090", "metrics port")
 	flag.Parse()
 
 	if id == "" {
@@ -129,53 +127,9 @@ func main() {
 	clientset := getClientset()
 	wks := NewWellKnownService(clientset, namespace, cmName)
 
-	if leaderOverride {
-		klog.Infof("Manual leader override enabled. This instance (%s) is the leader.", id)
-
-		// Run the discovery loop with context handling
-		go func() {
-			runLeaderTasks(ctx, wks)
-		}()
-
-	} else {
-		// Start the leader election code loop
-		leaderelection.RunOrDie(ctx, leaderelection.LeaderElectionConfig{
-			Lock: &resourcelock.LeaseLock{
-				LeaseMeta: metav1.ObjectMeta{
-					Name:      leaseLockName,
-					Namespace: namespace,
-				},
-				Client: clientset.CoordinationV1(),
-				LockConfig: resourcelock.ResourceLockConfig{
-					Identity: id,
-				},
-			},
-			ReleaseOnCancel: true,
-			LeaseDuration:   60 * time.Second,
-			RenewDeadline:   15 * time.Second,
-			RetryPeriod:     5 * time.Second,
-			Callbacks: leaderelection.LeaderCallbacks{
-				OnStartedLeading: func(ctx context.Context) {
-					klog.Infof("This instance is now the leader: %s", id)
-					runLeaderTasks(ctx, wks)
-				},
-				OnStoppedLeading: func() {
-					klog.Infof("Leader lost: %s", id)
-					os.Exit(0)
-				},
-				OnNewLeader: func(identity string) {
-					if identity == id {
-						return
-					}
-					klog.Infof("New leader elected: %s", identity)
-				},
-			},
-		})
-	}
-
 	// Start the server
 	go func() {
-		klog.Infof("Running /.well-known/{id} endpoint on :%s", serverPort)
+		klog.Infof("Starting /.well-known endpoint on :%s", serverPort)
 		if err := http.ListenAndServe(":"+serverPort, GetServer(wks)); err != nil {
 			klog.Error(err)
 			os.Exit(1)
@@ -184,19 +138,17 @@ func main() {
 
 	// Start the health server
 	go func() {
-		klog.Infof("Running /healthz endpoint on :%s", healthPort)
+		klog.Infof("Starting /healthz endpoint on :%s", healthPort)
 		if err := http.ListenAndServe(":"+healthPort, GetHealthServer()); err != nil {
 			klog.Error(err)
 			os.Exit(1)
 		}
 	}()
 
-	metricsPort := "9090" // You can set this via flag or environment variable
-
 	// Start the metrics server
 	go func() {
+		klog.Infof("Starting /metrics endpoint on :%s", metricsPort)
 		http.Handle("/metrics", promhttp.Handler())
-		log.Infof("Running metrics endpoint on :%s", metricsPort)
 		if err := http.ListenAndServe(":"+metricsPort, nil); err != nil {
 			log.Fatalf("Error starting metrics server: %v", err)
 		}
@@ -222,20 +174,17 @@ func main() {
 			OnStartedLeading: func(ctx context.Context) {
 				klog.Infof("This instance is now the leader: %s", id)
 
-				for {
-					wks.DiscoveryLoop(ctx)
-				}
+				runLeaderTasks(ctx, wks)
 			},
 			OnStoppedLeading: func() {
-				klog.Infof("leader lost: %s", id)
+				klog.Infof("Leader lost: %s", id)
 				os.Exit(0)
 			},
 			OnNewLeader: func(identity string) {
 				if identity == id {
-					klog.Infof("This instance is still the leader: %s", id)
-				} else {
-					klog.Infof("New leader elected: %s (this instance: %s)", identity, id)
+					return
 				}
+				klog.Infof("New leader elected: %s", identity)
 			},
 		},
 	})
diff --git a/server/wellknown.go b/server/wellknown.go
index c045489..63387e7 100644
--- a/server/wellknown.go
+++ b/server/wellknown.go
@@ -208,8 +208,6 @@ func (s *WellKnownService) collectData(ctx context.Context) (wkRegistry, error)
 		return reg, err
 	}
 
-	klog.Infof("Found %d services in namespace %s", len(svcs.Items), s.namespace)
-
 	for _, svc := range svcs.Items {
 		//klog.Infof("Processing service: %s", svc.GetName())