Add all controller metrics

This commit adds metrics of HierConfig and all other object controllers.
It includes total reconciliations and peak concurrent reconciliations
and related api writes.

Tested on GKE cluster and the metrics can all be viewed in Stackdriver.

incubator/hnc/cmd/manager/main.go

@@ -18,6 +18,7 @@ package main
 import (
 	"flag"
 	"os"
+	"time"
 
 	"contrib.go.opencensus.io/exporter/stackdriver"
 	corev1 "k8s.io/api/core/v1"
@@ -75,7 +76,11 @@ func main() {
 	// Exporters use Application Default Credentials to authenticate.
 	// See https://developers.google.com/identity/protocols/application-default-credentials
 	// for more details.
-	exporter, err := stackdriver.NewExporter(stackdriver.Options{})
+	exporter, err := stackdriver.NewExporter(stackdriver.Options{
+		// Stackdriver’s minimum stats reporting period must be >= 60 seconds.
+		// https://opencensus.io/exporters/supported-exporters/go/stackdriver/
+		ReportingInterval: 1 * time.Minute,
+	})
 	if err != nil {
 		setupLog.Error(err, "cannot create Stackdriver exporter")
 		os.Exit(1)

incubator/hnc/go.mod

@@ -3,6 +3,7 @@ module github.com/kubernetes-sigs/multi-tenancy/incubator/hnc
 go 1.12
 
 require (
+	contrib.go.opencensus.io/exporter/stackdriver v0.13.0
 	github.com/Azure/go-autorest/autorest v0.9.1 // indirect
 	github.com/Azure/go-autorest/autorest/adal v0.6.0 // indirect
 	github.com/emicklei/go-restful v2.10.0+incompatible // indirect
@@ -16,6 +17,7 @@ require (
 	github.com/onsi/gomega v1.7.0
 	github.com/peterbourgon/diskv v2.0.1+incompatible // indirect
 	github.com/spf13/cobra v0.0.5
+	go.opencensus.io v0.22.3
 	k8s.io/api v0.0.0-20190409021203-6e4e0e4f393b
 	k8s.io/apimachinery v0.0.0-20190404173353-6a84e37a896d
 	k8s.io/cli-runtime v0.0.0-20190314001948-2899ed30580f