Metrics Adapter: remove deprecated Prom Metrics and non-gRPC code

CHANGELOG.md

@@ -51,6 +51,7 @@ To learn more about active deprecations, we recommend checking [GitHub Discussio
 
 ### Improvements
 
+- **General**: Metrics Adapter: remove deprecated Prometheus Metrics and non-gRPC code ([#3930](https://github.com/kedacore/keda/issues/3930))
 - **Azure Data Exporer Scaler**: Use azidentity SDK ([#4489](https://github.com/kedacore/keda/issues/4489))
 - **GCP PubSub Scaler**: Make it more flexible for metrics ([#4243](https://github.com/kedacore/keda/issues/4243))
 

cmd/adapter/main.go

@@ -38,7 +38,6 @@ import (
 
 	kedav1alpha1 "github.com/kedacore/keda/v2/apis/keda/v1alpha1"
 	"github.com/kedacore/keda/v2/pkg/metricsservice"
-	prommetrics "github.com/kedacore/keda/v2/pkg/prommetrics/adapter"
 	kedaprovider "github.com/kedacore/keda/v2/pkg/provider"
 	"github.com/kedacore/keda/v2/pkg/scaling"
 	kedautil "github.com/kedacore/keda/v2/pkg/util"
@@ -55,8 +54,6 @@ type Adapter struct {
 var logger = klogr.New().WithName("keda_metrics_adapter")
 
 var (
-	prometheusMetricsPort     int
-	prometheusMetricsPath     string
 	adapterClientRequestQPS   float32
 	adapterClientRequestBurst int
 	metricsAPIServerPort      int
@@ -145,9 +142,6 @@ func (a *Adapter) makeProvider(ctx context.Context, globalHTTPTimeout time.Durat
 	handler := scaling.NewScaleHandler(mgr.GetClient(), nil, scheme, globalHTTPTimeout, recorder, secretInformer.Lister())
 	kubeInformerFactory.Start(ctx.Done())
 
-	prometheusServer := &prommetrics.PrometheusMetricServer{}
-	go func() { prometheusServer.NewServer(fmt.Sprintf(":%v", prometheusMetricsPort), prometheusMetricsPath) }()
-
 	logger.Info("Connecting Metrics Service gRPC client to the server", "address", metricsServiceAddr)
 	grpcClient, err := metricsservice.NewGrpcClient(metricsServiceAddr, a.SecureServing.ServerCert.CertDirectory)
 	if err != nil {
@@ -209,8 +203,6 @@ func main() {
 	cmd.Flags().StringVar(&cmd.Message, "msg", "starting adapter...", "startup message")
 	cmd.Flags().AddGoFlagSet(flag.CommandLine) // make sure we get the klog flags
 	cmd.Flags().IntVar(&metricsAPIServerPort, "port", 8080, "Set the port for the metrics API server")
-	cmd.Flags().IntVar(&prometheusMetricsPort, "metrics-port", 9022, "Set the port to expose prometheus metrics")
-	cmd.Flags().StringVar(&prometheusMetricsPath, "metrics-path", "/metrics", "Set the path for the prometheus metrics endpoint")
 	cmd.Flags().StringVar(&metricsServiceAddr, "metrics-service-address", generateDefaultMetricsServiceAddr(), "The address of the gRPRC Metrics Service Server.")
 	cmd.Flags().Float32Var(&adapterClientRequestQPS, "kube-api-qps", 20.0, "Set the QPS rate for throttling requests sent to the apiserver")
 	cmd.Flags().IntVar(&adapterClientRequestBurst, "kube-api-burst", 30, "Set the burst for throttling requests sent to the apiserver")

config/metrics-server/deployment.yaml

@@ -68,8 +68,6 @@ spec:
             name: https
           - containerPort: 8080
             name: http
-          - containerPort: 9022
-            name: metrics
           volumeMounts:
           - mountPath: /tmp
             name: temp-vol

config/metrics-server/service.yaml

@@ -16,8 +16,5 @@ spec:
   - name: http
     port: 80
     targetPort: 8080
-  - name: metrics
-    port: 9022
-    targetPort: 9022
   selector:
     app: keda-metrics-apiserver