enable separate metrics for content resources

to enable dashboards and library panels to track their fetch operations
separately, split up the metrics by resource. this is accomplished by
adding a new interface method to the GrafanaContentResource, and the
returned struct holds references to the relevant metrics, if any.

this also adds an additional guard to the http round tripper so that if
no metric is defined, we don't panic.

Author: diurnalist

api/v1beta1/content.go

@@ -1,6 +1,7 @@
 package v1beta1
 
 import (
+	"github.com/prometheus/client_golang/prometheus"
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"sigs.k8s.io/controller-runtime/pkg/client"
@@ -124,4 +125,13 @@ type GrafanaContentResource interface {
 	client.Object
 	GrafanaContentSpec() *GrafanaContentSpec
 	GrafanaContentStatus() *GrafanaContentStatus
+	GrafanaContentMetrics() GrafanaContentMetrics
+}
+
+// GrafanaContentMetrics holds runtime information about telemetry configured for a particular
+// content resource, allowing for resources to have different logical metrics.
+// +kubebuilder:object:generate=false
+type GrafanaContentMetrics struct {
+	URLRequestCounter                *prometheus.CounterVec
+	GrafanaComRevisionRequestCounter *prometheus.CounterVec
 }

api/v1beta1/grafanadashboard_types.go

@@ -19,6 +19,7 @@ package v1beta1
 import (
 	"time"
 
+	"github.com/grafana/grafana-operator/v5/controllers/metrics"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
@@ -124,6 +125,16 @@ func (in *GrafanaDashboard) GrafanaContentStatus() *GrafanaContentStatus {
 	return &in.Status.GrafanaContentStatus
 }
 
+// GrafanaContentMetrics implements GrafanaContentResource
+func (in *GrafanaDashboard) GrafanaContentMetrics() GrafanaContentMetrics {
+	return GrafanaContentMetrics{
+		URLRequestCounter:                metrics.DashboardUrlRequests,
+		GrafanaComRevisionRequestCounter: metrics.GrafanaComApiRevisionRequests,
+	}
+}
+
+var _ GrafanaContentResource = &GrafanaDashboard{}
+
 func (in *GrafanaDashboard) IsAllowCrossNamespaceImport() bool {
 	return in.Spec.AllowCrossNamespaceImport
 }

api/v1beta1/grafanalibrarypanel_types.go

@@ -3,6 +3,7 @@ package v1beta1
 import (
 	"time"
 
+	"github.com/grafana/grafana-operator/v5/controllers/metrics"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
@@ -120,6 +121,16 @@ func (in *GrafanaLibraryPanel) GrafanaContentStatus() *GrafanaContentStatus {
 	return &in.Status.GrafanaContentStatus
 }
 
+// GrafanaContentMetrics implements GrafanaContentResource
+func (in *GrafanaLibraryPanel) GrafanaContentMetrics() GrafanaContentMetrics {
+	return GrafanaContentMetrics{
+		URLRequestCounter: metrics.LibraryPanelUrlRequests,
+		// NOTE: we do not export the grafana.com request metric here b/c it's not supported.
+	}
+}
+
+var _ GrafanaContentResource = &GrafanaLibraryPanel{}
+
 func (in *GrafanaLibraryPanelList) Find(namespace string, name string) *GrafanaLibraryPanel {
 	for _, e := range in.Items {
 		if e.Namespace == namespace && e.Name == name {

controllers/client/round_tripper.go

@@ -49,7 +49,7 @@ func (in *instrumentedRoundTripper) RoundTrip(r *http.Request) (*http.Response,
 	}
 
 	resp, err := in.wrapped.RoundTrip(r)
-	if resp != nil {
+	if resp != nil && in.metric != nil {
 		in.metric.WithLabelValues(
 			in.relatedResource,
 			r.Method,

controllers/content/fetchers/grafana_com_fetcher.go

@@ -12,7 +12,6 @@ import (
 	"github.com/grafana/grafana-operator/v5/api/v1beta1"
 	client2 "github.com/grafana/grafana-operator/v5/controllers/client"
 	"github.com/grafana/grafana-operator/v5/controllers/content/cache"
-	"github.com/grafana/grafana-operator/v5/controllers/metrics"
 )
 
 const grafanaComDashboardApiUrlRoot = "https://grafana.com/api/dashboards"
@@ -59,7 +58,9 @@ func getLatestGrafanaComRevision(cr v1beta1.GrafanaContentResource, tlsConfig *t
 		return -1, err
 	}
 
-	client := client2.NewInstrumentedRoundTripper(fmt.Sprintf("%v/%v", cr.GetNamespace(), cr.GetName()), metrics.GrafanaComApiRevisionRequests, true, tlsConfig)
+	metric := cr.GrafanaContentMetrics().GrafanaComRevisionRequestCounter
+
+	client := client2.NewInstrumentedRoundTripper(fmt.Sprintf("%v/%v", cr.GetNamespace(), cr.GetName()), metric, true, tlsConfig)
 	response, err := client.RoundTrip(request)
 	if err != nil {
 		return -1, err

controllers/content/fetchers/url_fetcher.go

@@ -14,7 +14,6 @@ import (
 	"github.com/grafana/grafana-operator/v5/api/v1beta1"
 	grafanaClient "github.com/grafana/grafana-operator/v5/controllers/client"
 	"github.com/grafana/grafana-operator/v5/controllers/content/cache"
-	"github.com/grafana/grafana-operator/v5/controllers/metrics"
 
 	client2 "github.com/grafana/grafana-operator/v5/controllers/client"
 	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -38,7 +37,9 @@ func FetchFromUrl(ctx context.Context, cr v1beta1.GrafanaContentResource, c clie
 		return nil, err
 	}
 
-	client := client2.NewInstrumentedRoundTripper(fmt.Sprintf("%v/%v", cr.GetNamespace(), cr.GetName()), metrics.DashboardUrlRequests, true, tlsConfig)
+	metric := cr.GrafanaContentMetrics().URLRequestCounter
+
+	client := client2.NewInstrumentedRoundTripper(fmt.Sprintf("%v/%v", cr.GetNamespace(), cr.GetName()), metric, true, tlsConfig)
 	// basic auth is supported for dashboards from url
 	if spec.UrlAuthorization != nil && spec.UrlAuthorization.BasicAuth != nil {
 		username, err := grafanaClient.GetValueFromSecretKey(ctx, spec.UrlAuthorization.BasicAuth.Username, c, cr.GetNamespace())

controllers/content/suite_test.go

@@ -53,6 +53,10 @@ func (n *NopContentResource) GrafanaContentStatus() *v1beta1.GrafanaContentStatu
 	return &n.Status
 }
 
+func (n *NopContentResource) GrafanaContentMetrics() v1beta1.GrafanaContentMetrics {
+	return v1beta1.GrafanaContentMetrics{}
+}
+
 func (in *NopContentResource) DeepCopyObject() runtime.Object {
 	if c := in.DeepCopy(); c != nil {
 		return c

controllers/metrics/metrics.go

@@ -34,6 +34,13 @@ var (
 		Help:      "requests to fetch dashboards from urls",
 	}, []string{"dashboard", "method", "status"})
 
+	LibraryPanelUrlRequests = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "grafana_operator",
+		Subsystem: "librarypanels",
+		Name:      "requests",
+		Help:      "requests to fetch library panels from urls",
+	}, []string{"librarypanel", "method", "status"})
+
 	GrafanaComApiRevisionRequests = prometheus.NewCounterVec(prometheus.CounterOpts{
 		Namespace: "grafana_operator",
 		Subsystem: "dashboards",