Plugins: Add metric to track plugin backend target (#95976)

* add metric to track plugin backend target

* tidy

* fix test

pkg/infra/metrics/metrics.go

@@ -200,6 +200,8 @@ var (
 
 	grafanaPluginBuildInfoDesc *prometheus.GaugeVec
 
+	grafanaPluginTargetInfoDesc *prometheus.GaugeVec
+
 	// StatsTotalLibraryPanels is a metric of total number of library panels stored in Grafana.
 	StatsTotalLibraryPanels prometheus.Gauge
 
@@ -570,6 +572,12 @@ func init() {
 		Namespace: ExporterName,
 	}, []string{"plugin_id", "plugin_type", "version", "signature_status"})
 
+	grafanaPluginTargetInfoDesc = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Name:      "plugin_target_info",
+		Help:      "A metric with a constant '1' value labeled by pluginId and target",
+		Namespace: ExporterName,
+	}, []string{"plugin_id", "target"})
+
 	StatsTotalDashboardVersions = prometheus.NewGauge(prometheus.GaugeOpts{
 		Name:      "stat_totals_dashboard_versions",
 		Help:      "total amount of dashboard versions in the database",
@@ -710,6 +718,10 @@ func SetPluginBuildInformation(pluginID, pluginType, version, signatureStatus st
 	grafanaPluginBuildInfoDesc.WithLabelValues(pluginID, pluginType, version, signatureStatus).Set(1)
 }
 
+func SetPluginTargetInformation(pluginID, target string) {
+	grafanaPluginTargetInfoDesc.WithLabelValues(pluginID, target).Set(1)
+}
+
 func initMetricVars(reg prometheus.Registerer) {
 	reg.MustRegister(
 		MInstanceStart,
@@ -764,6 +776,7 @@ func initMetricVars(reg prometheus.Registerer) {
 		StatsTotalActiveAdmins,
 		StatsTotalDataSources,
 		grafanaPluginBuildInfoDesc,
+		grafanaPluginTargetInfoDesc,
 		StatsTotalDashboardVersions,
 		StatsTotalAnnotations,
 		StatsTotalAlertRules,

pkg/plugins/manager/fakes/fakes.go

@@ -127,6 +127,10 @@ func (pc *FakePluginClient) IsDecommissioned() bool {
 	return pc.decommissioned
 }
 
+func (pc *FakePluginClient) Target() backendplugin.Target {
+	return "test-target"
+}
+
 func (pc *FakePluginClient) CollectMetrics(ctx context.Context, req *backend.CollectMetricsRequest) (*backend.CollectMetricsResult, error) {
 	if pc.CollectMetricsHandlerFunc != nil {
 		return pc.CollectMetricsHandlerFunc(ctx, req)
@@ -646,3 +650,7 @@ func (p *FakeBackendPlugin) Kill() {
 	defer p.mutex.Unlock()
 	p.Running = false
 }
+
+func (p *FakeBackendPlugin) Target() backendplugin.Target {
+	return "test-target"
+}

pkg/services/pluginsintegration/pipeline/pipeline.go

@@ -73,6 +73,7 @@ func ProvideInitializationStage(cfg *config.PluginManagementCfg, pr registry.Ser
 			RegisterPluginRolesStep(roleRegistry),
 			RegisterActionSetsStep(actionSetRegistry),
 			ReportBuildMetrics,
+			ReportTargetMetrics,
 			initialization.PluginRegistrationStep(pr),
 		},
 	})

pkg/services/pluginsintegration/pipeline/steps.go

@@ -127,6 +127,16 @@ func ReportBuildMetrics(_ context.Context, p *plugins.Plugin) (*plugins.Plugin,
 	if !p.IsCorePlugin() && !p.IsBundledPlugin() {
 		metrics.SetPluginBuildInformation(p.ID, string(p.Type), p.Info.Version, string(p.Signature))
 	}
+
+	return p, nil
+}
+
+// ReportTargetMetrics reports target information for all backend plugins.
+func ReportTargetMetrics(_ context.Context, p *plugins.Plugin) (*plugins.Plugin, error) {
+	if p.Backend {
+		metrics.SetPluginTargetInformation(p.ID, string(p.Target()))
+	}
+
 	return p, nil
 }