Use client generator to generate all k8s clients and add respective client-go metrics (#2668)

* Define client generator to generate all k8s clients
* Increase QPS and burst values
* Capture client-go metrics
* Support for controller runtime metrics

Signed-off-by: Sanket Sudake <sanketsudake@gmail.com>

pkg/router/metrics.go

@@ -2,7 +2,8 @@ package router
 
 import (
 	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promauto"
+
+	"github.com/fission/fission/pkg/utils/metrics"
 )
 
 var (
@@ -15,21 +16,21 @@ var (
 	// code: http status code
 	// path: the client call the function on which http path
 	// method: the function's http method
-	functionCalls = promauto.NewCounterVec(
+	functionCalls = prometheus.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "fission_function_calls_total",
 			Help: "Count of Fission function calls",
 		},
 		labelsStrings,
 	)
-	functionCallErrors = promauto.NewCounterVec(
+	functionCallErrors = prometheus.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "fission_function_errors_total",
 			Help: "Count of Fission function errors",
 		},
 		labelsStrings,
 	)
-	functionCallOverhead = promauto.NewSummaryVec(
+	functionCallOverhead = prometheus.NewSummaryVec(
 		prometheus.SummaryOpts{
 			Name:       "fission_function_overhead_seconds",
 			Help:       "The function call delay caused by fission.",
@@ -38,3 +39,10 @@ var (
 		labelsStrings,
 	)
 )
+
+func init() {
+	registry := metrics.Registry
+	registry.MustRegister(functionCalls)
+	registry.MustRegister(functionCallErrors)
+	registry.MustRegister(functionCallOverhead)
+}

pkg/router/router.go

@@ -90,9 +90,14 @@ func serve(ctx context.Context, logger *zap.Logger, port int,
 func Start(ctx context.Context, logger *zap.Logger, port int, executorURL string) {
 	fmap := makeFunctionServiceMap(logger, time.Minute)
 
-	fissionClient, kubeClient, _, _, err := crd.MakeFissionClient()
+	clientGen := crd.NewClientGenerator()
+	fissionClient, err := clientGen.GetFissionClient()
 	if err != nil {
-		logger.Fatal("error connecting to kubernetes API", zap.Error(err))
+		logger.Fatal("error making the fission client", zap.Error(err))
+	}
+	kubeClient, err := clientGen.GetKubernetesClient()
+	if err != nil {
+		logger.Fatal("error making the kube client", zap.Error(err))
 	}
 
 	err = crd.WaitForCRDs(ctx, logger, fissionClient)