Added new handler for metrics

go.mod

@@ -5,6 +5,7 @@ go 1.13
 require (
 	github.com/onsi/ginkgo v1.12.1
 	github.com/onsi/gomega v1.10.1
+	github.com/prometheus/client_golang v1.0.0
 	github.com/stretchr/testify v1.5.1
 	k8s.io/api v0.18.4
 	k8s.io/apimachinery v0.18.4

go.sum

@@ -457,19 +457,13 @@ gotest.tools v2.2.0+incompatible/go.mod h1:DsYFclhRJ6vuDpmuTbkuFWG+y2sxOXAzmJt81
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 honnef.co/go/tools v0.0.0-20190106161140-3f1c8253044a/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 honnef.co/go/tools v0.0.0-20190523083050-ea95bdfd59fc/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
-k8s.io/api v0.18.2 h1:wG5g5ZmSVgm5B+eHMIbI9EGATS2L8Z72rda19RIEgY8=
-k8s.io/api v0.18.2/go.mod h1:SJCWI7OLzhZSvbY7U8zwNl9UA4o1fizoug34OV/2r78=
 k8s.io/api v0.18.4 h1:8x49nBRxuXGUlDlwlWd3RMY1SayZrzFfxea3UZSkFw4=
 k8s.io/api v0.18.4/go.mod h1:lOIQAKYgai1+vz9J7YcDZwC26Z0zQewYOGWdyIPUUQ4=
 k8s.io/apiextensions-apiserver v0.18.4 h1:Y3HGERmS8t9u12YNUFoOISqefaoGRuTc43AYCLzWmWE=
 k8s.io/apiextensions-apiserver v0.18.4/go.mod h1:NYeyeYq4SIpFlPxSAB6jHPIdvu3hL0pc36wuRChybio=
-k8s.io/apimachinery v0.18.2 h1:44CmtbmkzVDAhCpRVSiP2R5PPrC2RtlIv/MoB8xpdRA=
-k8s.io/apimachinery v0.18.2/go.mod h1:9SnR/e11v5IbyPCGbvJViimtJ0SwHG4nfZFjU77ftcA=
 k8s.io/apimachinery v0.18.4 h1:ST2beySjhqwJoIFk6p7Hp5v5O0hYY6Gngq/gUYXTPIA=
 k8s.io/apimachinery v0.18.4/go.mod h1:OaXp26zu/5J7p0f92ASynJa1pZo06YlV9fG7BoWbCko=
 k8s.io/apiserver v0.18.4/go.mod h1:q+zoFct5ABNnYkGIaGQ3bcbUNdmPyOCoEBcg51LChY8=
-k8s.io/client-go v0.18.2 h1:aLB0iaD4nmwh7arT2wIn+lMnAq7OswjaejkQ8p9bBYE=
-k8s.io/client-go v0.18.2/go.mod h1:Xcm5wVGXX9HAA2JJ2sSBUn3tCJ+4SVlCbl2MNNv+CIU=
 k8s.io/client-go v0.18.4 h1:un55V1Q/B3JO3A76eS0kUSywgGK/WR3BQ8fHQjNa6Zc=
 k8s.io/client-go v0.18.4/go.mod h1:f5sXwL4yAZRkAtzOxRWUhA/N8XzGCb+nPZI8PfobZ9g=
 k8s.io/code-generator v0.18.4/go.mod h1:TgNEVx9hCyPGpdtCWA34olQYLkh3ok9ar7XfSsr8b6c=
@@ -482,8 +476,6 @@ k8s.io/klog v1.0.0 h1:Pt+yjF5aB1xDSVbau4VsWe+dQNzA0qv1LlXdC2dF6Q8=
 k8s.io/klog v1.0.0/go.mod h1:4Bi6QPql/J/LkTDqv7R/cd3hPo4k2DG6Ptcz060Ez5I=
 k8s.io/klog/v2 v2.0.0 h1:Foj74zO6RbjjP4hBEKjnYtjjAhGg4jNynUdYF6fJrok=
 k8s.io/klog/v2 v2.0.0/go.mod h1:PBfzABfn139FHAV07az/IF9Wp1bkk3vpT2XSJ76fSDE=
-k8s.io/kube-openapi v0.0.0-20200121204235-bf4fb3bd569c h1:/KUFqjjqAcY4Us6luF5RDNZ16KJtb49HfR3ZHB9qYXM=
-k8s.io/kube-openapi v0.0.0-20200121204235-bf4fb3bd569c/go.mod h1:GRQhZsXIAJ1xR0C9bd8UpWHZ5plfAS9fzPjJuQ6JL3E=
 k8s.io/kube-openapi v0.0.0-20200410145947-61e04a5be9a6 h1:Oh3Mzx5pJ+yIumsAD0MOECPVeXsVot0UkiaCGVyfGQY=
 k8s.io/kube-openapi v0.0.0-20200410145947-61e04a5be9a6/go.mod h1:GRQhZsXIAJ1xR0C9bd8UpWHZ5plfAS9fzPjJuQ6JL3E=
 k8s.io/utils v0.0.0-20200324210504-a9aa75ae1b89 h1:d4vVOjXm687F1iLSP2q3lyPPuyvTUt3aVoBpi2DqRsU=

handler/instrumented_enqueue_object.go

@@ -0,0 +1,83 @@
+// Copyright 2020 The Operator-SDK Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package handler
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/client-go/util/workqueue"
+	"sigs.k8s.io/controller-runtime/pkg/event"
+	"sigs.k8s.io/controller-runtime/pkg/handler"
+
+	"github.com/operator-framework/operator-lib/handler/internal/metrics"
+)
+
+// InstrumentedEnqueueRequestForObject wraps controller-runtime handler for
+// "EnqueueRequestForObject", and sets up primary resource metrics on event
+// handlers. The main objective of this handler is to set prometheues metrics
+// when create/update/delete events occur. These metrics contain below
+// information on resource.
+//
+// resource_created_at_seconds{"name", "namespace", "group", "version", "kind"}
+//
+// '&handler.InstrumentedEnqueueRequestForObject{}' is used to call the handler.
+type InstrumentedEnqueueRequestForObject struct {
+	handler.EnqueueRequestForObject
+}
+
+// Create implements EventHandler, and creates the metrics.
+func (h InstrumentedEnqueueRequestForObject) Create(e event.CreateEvent, q workqueue.RateLimitingInterface) {
+	setResourceMetric(e.Meta, e.Object)
+	h.EnqueueRequestForObject.Create(e, q)
+}
+
+// Update implements EventHandler, and updates the metrics.
+func (h InstrumentedEnqueueRequestForObject) Update(e event.UpdateEvent, q workqueue.RateLimitingInterface) {
+	setResourceMetric(e.MetaOld, e.ObjectOld)
+	setResourceMetric(e.MetaNew, e.ObjectNew)
+
+	h.EnqueueRequestForObject.Update(e, q)
+}
+
+// Delete implements EventHandler, and deletes metrics.
+func (h InstrumentedEnqueueRequestForObject) Delete(e event.DeleteEvent, q workqueue.RateLimitingInterface) {
+	deleteResourceMetric(e.Meta, e.Object)
+	h.EnqueueRequestForObject.Delete(e, q)
+}
+
+func setResourceMetric(metadata metav1.Object, obj runtime.Object) {
+	if metadata != nil && obj != nil {
+		labels := getResourceLabels(metadata, obj)
+		m, _ := metrics.ResourceCreatedAt.GetMetricWith(labels)
+		m.Set(float64(metadata.GetCreationTimestamp().UTC().Unix()))
+	}
+}
+
+func deleteResourceMetric(metadata metav1.Object, obj runtime.Object) {
+	if metadata != nil && obj != nil {
+		labels := getResourceLabels(metadata, obj)
+		_ = metrics.ResourceCreatedAt.Delete(labels)
+	}
+}
+
+func getResourceLabels(metadata metav1.Object, obj runtime.Object) map[string]string {
+	return map[string]string{
+		"name":      metadata.GetName(),
+		"namespace": metadata.GetNamespace(),
+		"group":     obj.GetObjectKind().GroupVersionKind().Group,
+		"version":   obj.GetObjectKind().GroupVersionKind().Version,
+		"kind":      obj.GetObjectKind().GroupVersionKind().Kind,
+	}
+}

handler/internal/metrics/metrics.go

@@ -0,0 +1,33 @@
+// Copyright 2020 The Operator-SDK Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package metrics
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"sigs.k8s.io/controller-runtime/pkg/metrics"
+)
+
+// ResourceCreatedAt creates new prometheus metrics for primary resource,
+// with information {"name", "namespace", "group", "version", "kind"}
+var ResourceCreatedAt = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+	Name: "resource_created_at_seconds",
+	Help: "Timestamp at which a resource was created",
+}, []string{"name", "namespace", "group", "version", "kind"})
+
+func init() {
+	metrics.Registry.MustRegister(
+		ResourceCreatedAt,
+	)
+}