prometheus: Add ip labels to server metrics

Add two labels grpc_server_ip and grpc_client_ip to the server metrics
when option WithServerIPLabelsEnabled() is set. These labels are not
added by default for compatibility.

Signed-off-by: diabloneo <[email protected]>

README.md

@@ -18,21 +18,21 @@ Additional great feature of interceptors is the fact we can chain those. For exa
 
 ```go mdox-exec="sed -n '136,151p' examples/server/main.go"
 	grpcSrv := grpc.NewServer(
+		grpc.StatsHandler(otelgrpc.NewServerHandler()),
 		grpc.ChainUnaryInterceptor(
-			// Order matters e.g. tracing interceptor have to create span first for the later exemplars to work.
-			otelgrpc.UnaryServerInterceptor(),
 			srvMetrics.UnaryServerInterceptor(grpcprom.WithExemplarFromContext(exemplarFromContext)),
 			logging.UnaryServerInterceptor(interceptorLogger(rpcLogger), logging.WithFieldsFromContext(logTraceID)),
 			selector.UnaryServerInterceptor(auth.UnaryServerInterceptor(authFn), selector.MatchFunc(allButHealthZ)),
 			recovery.UnaryServerInterceptor(recovery.WithRecoveryHandler(grpcPanicRecoveryHandler)),
 		),
 		grpc.ChainStreamInterceptor(
-			otelgrpc.StreamServerInterceptor(),
 			srvMetrics.StreamServerInterceptor(grpcprom.WithExemplarFromContext(exemplarFromContext)),
 			logging.StreamServerInterceptor(interceptorLogger(rpcLogger), logging.WithFieldsFromContext(logTraceID)),
 			selector.StreamServerInterceptor(auth.StreamServerInterceptor(authFn), selector.MatchFunc(allButHealthZ)),
 			recovery.StreamServerInterceptor(recovery.WithRecoveryHandler(grpcPanicRecoveryHandler)),
 		),
+	)
+	t := &testpb.TestPingService{}
 ```
 
 This pattern offers clean and explicit shared functionality for all your gRPC methods. Full, buildable examples can be found in [examples](examples) directory.

providers/prometheus/reporter.go

@@ -5,15 +5,20 @@ package prometheus
 
 import (
 	"context"
+	"net/netip"
 	"time"
 
 	"github.com/grpc-ecosystem/go-grpc-middleware/v2/interceptors"
 	"github.com/prometheus/client_golang/prometheus"
+	grpcpeer "google.golang.org/grpc/peer"
 )
 
 type reporter struct {
-	clientMetrics   *ClientMetrics
-	serverMetrics   *ServerMetrics
+	clientMetrics *ClientMetrics
+	serverMetrics *ServerMetrics
+
+	grpcServerIP    string
+	grpcClientIP    string
 	typ             interceptors.GRPCType
 	service, method string
 	kind            Kind
@@ -28,9 +33,17 @@ func (r *reporter) PostCall(err error, rpcDuration time.Duration) {
 	// perform handling of metrics from code
 	switch r.kind {
 	case KindServer:
-		r.incrementWithExemplar(r.serverMetrics.serverHandledCounter, string(r.typ), r.service, r.method, code.String())
+		lvals := []string{string(r.typ), r.service, r.method, code.String()}
+		if r.serverMetrics.ipLabelsEnabled {
+			lvals = append(lvals, r.grpcServerIP, r.grpcClientIP)
+		}
+		r.incrementWithExemplar(r.serverMetrics.serverHandledCounter, lvals...)
 		if r.serverMetrics.serverHandledHistogram != nil {
-			r.observeWithExemplar(r.serverMetrics.serverHandledHistogram, rpcDuration.Seconds(), string(r.typ), r.service, r.method)
+			lvals = []string{string(r.typ), r.service, r.method}
+			if r.serverMetrics.ipLabelsEnabled {
+				lvals = append(lvals, r.grpcServerIP, r.grpcClientIP)
+			}
+			r.observeWithExemplar(r.serverMetrics.serverHandledHistogram, rpcDuration.Seconds(), lvals...)
 		}
 
 	case KindClient:
@@ -44,7 +57,11 @@ func (r *reporter) PostCall(err error, rpcDuration time.Duration) {
 func (r *reporter) PostMsgSend(_ any, _ error, sendDuration time.Duration) {
 	switch r.kind {
 	case KindServer:
-		r.incrementWithExemplar(r.serverMetrics.serverStreamMsgSent, string(r.typ), r.service, r.method)
+		lvals := []string{string(r.typ), r.service, r.method}
+		if r.serverMetrics.ipLabelsEnabled {
+			lvals = append(lvals, r.grpcServerIP, r.grpcClientIP)
+		}
+		r.incrementWithExemplar(r.serverMetrics.serverStreamMsgSent, lvals...)
 	case KindClient:
 		r.incrementWithExemplar(r.clientMetrics.clientStreamMsgSent, string(r.typ), r.service, r.method)
 		if r.clientMetrics.clientStreamSendHistogram != nil {
@@ -56,7 +73,11 @@ func (r *reporter) PostMsgSend(_ any, _ error, sendDuration time.Duration) {
 func (r *reporter) PostMsgReceive(_ any, _ error, recvDuration time.Duration) {
 	switch r.kind {
 	case KindServer:
-		r.incrementWithExemplar(r.serverMetrics.serverStreamMsgReceived, string(r.typ), r.service, r.method)
+		lvals := []string{string(r.typ), r.service, r.method}
+		if r.serverMetrics.ipLabelsEnabled {
+			lvals = append(lvals, r.grpcServerIP, r.grpcClientIP)
+		}
+		r.incrementWithExemplar(r.serverMetrics.serverStreamMsgReceived, lvals...)
 	case KindClient:
 		r.incrementWithExemplar(r.clientMetrics.clientStreamMsgReceived, string(r.typ), r.service, r.method)
 		if r.clientMetrics.clientStreamRecvHistogram != nil {
@@ -65,6 +86,14 @@ func (r *reporter) PostMsgReceive(_ any, _ error, recvDuration time.Duration) {
 	}
 }
 
+func (r *reporter) incrementWithExemplar(c *prometheus.CounterVec, lvals ...string) {
+	c.WithLabelValues(lvals...).(prometheus.ExemplarAdder).AddWithExemplar(1, r.exemplar)
+}
+
+func (r *reporter) observeWithExemplar(h *prometheus.HistogramVec, value float64, lvals ...string) {
+	h.WithLabelValues(lvals...).(prometheus.ExemplarObserver).ObserveWithExemplar(value, r.exemplar)
+}
+
 type reportable struct {
 	clientMetrics *ClientMetrics
 	serverMetrics *ServerMetrics
@@ -86,10 +115,11 @@ func (rep *reportable) reporter(ctx context.Context, sm *ServerMetrics, cm *Clie
 	r := &reporter{
 		clientMetrics: cm,
 		serverMetrics: sm,
-		typ:           meta.Typ,
-		service:       meta.Service,
-		method:        meta.Method,
-		kind:          kind,
+
+		typ:     meta.Typ,
+		service: meta.Service,
+		method:  meta.Method,
+		kind:    kind,
 	}
 	if c.exemplarFn != nil {
 		r.exemplar = c.exemplarFn(ctx)
@@ -99,15 +129,28 @@ func (rep *reportable) reporter(ctx context.Context, sm *ServerMetrics, cm *Clie
 	case KindClient:
 		r.incrementWithExemplar(r.clientMetrics.clientStartedCounter, string(r.typ), r.service, r.method)
 	case KindServer:
-		r.incrementWithExemplar(r.serverMetrics.serverStartedCounter, string(r.typ), r.service, r.method)
+
+		lvals := []string{string(r.typ), r.service, r.method}
+		if r.serverMetrics.ipLabelsEnabled {
+			if peer, ok := grpcpeer.FromContext(ctx); ok {
+				// Fallback to net.Addr.String() when ParseAddrPort failed, because it already contains
+				// necessary information to be added to the label and we
+
+				// This is server side, so LocalAddr is server's address.
+				if addrPort, e := netip.ParseAddrPort(peer.LocalAddr.String()); e != nil {
+					r.grpcServerIP = peer.LocalAddr.String()
+				} else {
+					r.grpcServerIP = addrPort.Addr().String()
+				}
+				if addrPort, e := netip.ParseAddrPort(peer.Addr.String()); e != nil {
+					r.grpcClientIP = peer.Addr.String()
+				} else {
+					r.grpcClientIP = addrPort.Addr().String()
+				}
+			}
+			lvals = append(lvals, r.grpcServerIP, r.grpcClientIP)
+		}
+		r.incrementWithExemplar(r.serverMetrics.serverStartedCounter, lvals...)
 	}
 	return r, ctx
 }
-
-func (r *reporter) incrementWithExemplar(c *prometheus.CounterVec, lvals ...string) {
-	c.WithLabelValues(lvals...).(prometheus.ExemplarAdder).AddWithExemplar(1, r.exemplar)
-}
-
-func (r *reporter) observeWithExemplar(h *prometheus.HistogramVec, value float64, lvals ...string) {
-	h.WithLabelValues(lvals...).(prometheus.ExemplarObserver).ObserveWithExemplar(value, r.exemplar)
-}

providers/prometheus/server_metrics.go

@@ -13,6 +13,7 @@ import (
 // ServerMetrics represents a collection of metrics to be registered on a
 // Prometheus metrics registry for a gRPC server.
 type ServerMetrics struct {
+	ipLabelsEnabled         bool
 	serverStartedCounter    *prometheus.CounterVec
 	serverHandledCounter    *prometheus.CounterVec
 	serverStreamMsgReceived *prometheus.CounterVec
@@ -27,29 +28,43 @@ type ServerMetrics struct {
 func NewServerMetrics(opts ...ServerMetricsOption) *ServerMetrics {
 	var config serverMetricsConfig
 	config.apply(opts)
-	return &ServerMetrics{
+
+	addIPLables := func(orig []string) []string {
+		if config.ipLabelsEnabled {
+			return serverMetricAddIPLabel(orig)
+		}
+		return orig
+	}
+
+	sm := &ServerMetrics{
+		ipLabelsEnabled: config.ipLabelsEnabled,
 		serverStartedCounter: prometheus.NewCounterVec(
 			config.counterOpts.apply(prometheus.CounterOpts{
 				Name: "grpc_server_started_total",
 				Help: "Total number of RPCs started on the server.",
-			}), []string{"grpc_type", "grpc_service", "grpc_method"}),
+			}), addIPLables([]string{"grpc_type", "grpc_service", "grpc_method"})),
 		serverHandledCounter: prometheus.NewCounterVec(
 			config.counterOpts.apply(prometheus.CounterOpts{
 				Name: "grpc_server_handled_total",
 				Help: "Total number of RPCs completed on the server, regardless of success or failure.",
-			}), []string{"grpc_type", "grpc_service", "grpc_method", "grpc_code"}),
+			}), addIPLables([]string{"grpc_type", "grpc_service", "grpc_method", "grpc_code"})),
 		serverStreamMsgReceived: prometheus.NewCounterVec(
 			config.counterOpts.apply(prometheus.CounterOpts{
 				Name: "grpc_server_msg_received_total",
 				Help: "Total number of RPC stream messages received on the server.",
-			}), []string{"grpc_type", "grpc_service", "grpc_method"}),
+			}), addIPLables([]string{"grpc_type", "grpc_service", "grpc_method"})),
 		serverStreamMsgSent: prometheus.NewCounterVec(
 			config.counterOpts.apply(prometheus.CounterOpts{
 				Name: "grpc_server_msg_sent_total",
 				Help: "Total number of gRPC stream messages sent by the server.",
-			}), []string{"grpc_type", "grpc_service", "grpc_method"}),
-		serverHandledHistogram: config.serverHandledHistogram,
+			}), addIPLables([]string{"grpc_type", "grpc_service", "grpc_method"})),
+	}
+	if config.serverHandledHistogramEnabled {
+		sm.serverHandledHistogram = newServerHandlingTimeHistogram(
+			config.ipLabelsEnabled, config.serverHandledHistogramOptions)
 	}
+
+	return sm
 }
 
 // Describe sends the super-set of all possible descriptors of metrics
@@ -95,15 +110,27 @@ func (m *ServerMetrics) InitializeMetrics(server reflection.ServiceInfoProvider)
 func (m *ServerMetrics) preRegisterMethod(serviceName string, mInfo *grpc.MethodInfo) {
 	methodName := mInfo.Name
 	methodType := string(typeFromMethodInfo(mInfo))
+
+	lvals := []string{methodType, serviceName, methodName}
+	if m.ipLabelsEnabled {
+		// Because netip.Addr.String() returns "invalid IP" for zero Addr,
+		// we use this value with grpc_server and grpc_client.
+		lvals = append(lvals, "invalid IP", "invalid IP")
+	}
 	// These are just references (no increments), as just referencing will create the labels but not set values.
-	_, _ = m.serverStartedCounter.GetMetricWithLabelValues(methodType, serviceName, methodName)
-	_, _ = m.serverStreamMsgReceived.GetMetricWithLabelValues(methodType, serviceName, methodName)
-	_, _ = m.serverStreamMsgSent.GetMetricWithLabelValues(methodType, serviceName, methodName)
+	_, _ = m.serverStartedCounter.GetMetricWithLabelValues(lvals...)
+	_, _ = m.serverStreamMsgReceived.GetMetricWithLabelValues(lvals...)
+	_, _ = m.serverStreamMsgSent.GetMetricWithLabelValues(lvals...)
 	if m.serverHandledHistogram != nil {
-		_, _ = m.serverHandledHistogram.GetMetricWithLabelValues(methodType, serviceName, methodName)
+		_, _ = m.serverHandledHistogram.GetMetricWithLabelValues(lvals...)
 	}
+
 	for _, code := range interceptors.AllCodes {
-		_, _ = m.serverHandledCounter.GetMetricWithLabelValues(methodType, serviceName, methodName, code.String())
+		lvals = []string{methodType, serviceName, methodName, code.String()}
+		if m.ipLabelsEnabled {
+			lvals = append(lvals, "invalid IP", "invalid IP")
+		}
+		_, _ = m.serverHandledCounter.GetMetricWithLabelValues(lvals...)
 	}
 }
 

providers/prometheus/server_options.go

@@ -9,14 +9,23 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 )
 
+func serverMetricAddIPLabel(orig []string) []string {
+	return append(orig, "grpc_server_ip", "grpc_client_ip")
+}
+
 type exemplarFromCtxFn func(ctx context.Context) prometheus.Labels
 
 type serverMetricsConfig struct {
+	// ipLabelsEnabled control whether to add grpc_server and grpc_client labels to metrics.
+	ipLabelsEnabled bool
+
 	counterOpts counterOptions
-	// serverHandledHistogram can be nil.
-	serverHandledHistogram *prometheus.HistogramVec
+
+	serverHandledHistogramEnabled bool
+	serverHandledHistogramOptions []HistogramOption
 }
 
+// ServerMetricsOption configures how we set up the server metrics.
 type ServerMetricsOption func(*serverMetricsConfig)
 
 func (c *serverMetricsConfig) apply(opts []ServerMetricsOption) {
@@ -32,17 +41,33 @@ func WithServerCounterOptions(opts ...CounterOption) ServerMetricsOption {
 	}
 }
 
+func newServerHandlingTimeHistogram(ipLabelsEnabled bool, opts []HistogramOption) *prometheus.HistogramVec {
+	labels := []string{"grpc_type", "grpc_service", "grpc_method"}
+	if ipLabelsEnabled {
+		labels = serverMetricAddIPLabel(labels)
+	}
+	return prometheus.NewHistogramVec(
+		histogramOptions(opts).apply(prometheus.HistogramOpts{
+			Name:    "grpc_server_handling_seconds",
+			Help:    "Histogram of response latency (seconds) of gRPC that had been application-level handled by the server.",
+			Buckets: prometheus.DefBuckets,
+		}),
+		labels,
+	)
+}
+
 // WithServerHandlingTimeHistogram turns on recording of handling time of RPCs.
 // Histogram metrics can be very expensive for Prometheus to retain and query.
 func WithServerHandlingTimeHistogram(opts ...HistogramOption) ServerMetricsOption {
 	return func(o *serverMetricsConfig) {
-		o.serverHandledHistogram = prometheus.NewHistogramVec(
-			histogramOptions(opts).apply(prometheus.HistogramOpts{
-				Name:    "grpc_server_handling_seconds",
-				Help:    "Histogram of response latency (seconds) of gRPC that had been application-level handled by the server.",
-				Buckets: prometheus.DefBuckets,
-			}),
-			[]string{"grpc_type", "grpc_service", "grpc_method"},
-		)
+		o.serverHandledHistogramEnabled = true
+		o.serverHandledHistogramOptions = opts
+	}
+}
+
+// WithServerIPLabelsEnabled enables adding grpc_server and grpc_client labels to metrics.
+func WithServerIPLabelsEnabled() ServerMetricsOption {
+	return func(o *serverMetricsConfig) {
+		o.ipLabelsEnabled = true
 	}
 }