Instrument backend plugin requests (#23346)

pkg/plugins/backendplugin/instrumentation.go

@@ -0,0 +1,47 @@
+package backendplugin
+
+import (
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	pluginRequestCounter  *prometheus.CounterVec
+	pluginRequestDuration *prometheus.SummaryVec
+)
+
+func init() {
+	pluginRequestCounter = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "grafana",
+		Name:      "plugin_request_total",
+		Help:      "The total amount of plugin requests",
+	}, []string{"plugin_id", "endpoint", "status"})
+
+	pluginRequestDuration = prometheus.NewSummaryVec(prometheus.SummaryOpts{
+		Namespace:  "grafana",
+		Name:       "plugin_request_duration_milliseconds",
+		Help:       "Plugin request duration",
+		Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
+	}, []string{"plugin_id", "endpoint"})
+
+	prometheus.MustRegister(pluginRequestCounter, pluginRequestDuration)
+}
+
+// InstrumentPluginRequest instruments success rate and latency of `fn`
+func InstrumentPluginRequest(pluginID string, endpoint string, fn func() error) error {
+	status := "ok"
+
+	start := time.Now()
+
+	err := fn()
+	if err != nil {
+		status = "error"
+	}
+
+	elapsed := time.Since(start) / time.Millisecond
+	pluginRequestDuration.WithLabelValues(pluginID, endpoint).Observe(float64(elapsed))
+	pluginRequestCounter.WithLabelValues(pluginID, endpoint, status).Inc()
+
+	return err
+}