snapshot of https://github.com/grpc/grpc-go.git (master, 2026-09-15; blobs > 131072B omitted)

examples/features/csm_observability/README.md

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+# CSM Observability
+
+This examples shows how to configure CSM Observability for gRPC client and
+server applications (configured once per binary), and shows what type of
+telemetry data it can produce for certain RPCs with additional CSM Labels. The
+gRPC Client accepts configuration from an xDS Control plane as the default
+address that it connects to is "xds:///helloworld:50051", but this can be
+overridden with the command line flag --server_addr. This can be plugged into
+the steps outlined in the CSM Observability User Guide.
+
+## Try it (locally if overwritten xDS Address)
+
+```
+go run server/main.go
+```
+
+```
+go run client/main.go
+```
+
+Curl to the port where Prometheus exporter is outputting metrics data:
+```
+curl localhost:9464/metrics
+```
+
+# Building
+From the grpc-go directory:
+
+Client:
+docker build -t <TAG> -f examples/features/csm_observability/client/Dockerfile .
+
+Server:
+docker build -t <TAG> -f examples/features/csm_observability/server/Dockerfile .
+
+Note that this example will not work by default, as the client uses an xDS
+Scheme and thus needs xDS Resources to connect to the server. Deploy the built
+client and server containers within Cloud Service Mesh in order for this example
+to work, or overwrite target to point to :<server serving port>.

examples/features/csm_observability/client/Dockerfile

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+# Copyright 2024 gRPC 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.
+
+# Dockerfile for building the example client. To build the image, run the
+# following command from grpc-go directory:
+# docker build -t <TAG> -f examples/features/csm_observability/client/Dockerfile .
+FROM golang:1.25-alpine as build
+
+RUN apk --no-cache add curl
+
+# Make a grpc-go directory and copy the repo into it.
+WORKDIR /go/src/grpc-go
+COPY . .
+
+# Build a static binary without cgo so that we can copy just the binary in the
+# final image, and can get rid of the Go compiler and gRPC-Go dependencies.
+RUN cd examples/features/csm_observability/client && go build -tags osusergo,netgo .
+
+FROM alpine
+RUN apk --no-cache add curl
+COPY --from=build /go/src/grpc-go/examples/features/csm_observability/client/client .
+ENV GRPC_GO_LOG_VERBOSITY_LEVEL=99
+ENV GRPC_GO_LOG_SEVERITY_LEVEL="info"
+ENTRYPOINT ["./client"]

examples/features/csm_observability/client/main.go

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+/*
+ *
+ * Copyright 2024 gRPC 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.
+ *
+ */
+
+// Binary client is a client for the CSM Observability example.
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log"
+	"net/http"
+	"time"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+	xdscreds "google.golang.org/grpc/credentials/xds"
+	pb "google.golang.org/grpc/examples/helloworld/helloworld"
+	"google.golang.org/grpc/stats/opentelemetry"
+	"google.golang.org/grpc/stats/opentelemetry/csm"
+	_ "google.golang.org/grpc/xds" // To install the xds resolvers and balancers.
+
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"go.opentelemetry.io/otel/exporters/prometheus"
+	"go.opentelemetry.io/otel/sdk/metric"
+)
+
+const defaultName = "world"
+
+var (
+	target             = flag.String("target", "xds:///helloworld:50051", "the server address to connect to")
+	prometheusEndpoint = flag.String("prometheus_endpoint", ":9464", "the Prometheus exporter endpoint")
+	name               = flag.String("name", defaultName, "Name to greet")
+)
+
+func main() {
+	flag.Parse()
+	exporter, err := prometheus.New()
+	if err != nil {
+		log.Fatalf("Failed to start prometheus exporter: %v", err)
+	}
+	provider := metric.NewMeterProvider(metric.WithReader(exporter))
+	go http.ListenAndServe(*prometheusEndpoint, promhttp.Handler())
+
+	cleanup := csm.EnableObservability(context.Background(), opentelemetry.Options{MetricsOptions: opentelemetry.MetricsOptions{MeterProvider: provider}})
+	defer cleanup()
+
+	// Set up xds credentials that fall back to insecure as described in:
+	// https://cloud.google.com/service-mesh/docs/service-routing/security-proxyless-setup#workloads_are_unable_to_communicate_in_the_security_setup.
+	creds, err := xdscreds.NewClientCredentials(xdscreds.ClientOptions{FallbackCreds: insecure.NewCredentials()})
+	if err != nil {
+		log.Fatalf("Failed to create xDS credentials: %v", err)
+	}
+	cc, err := grpc.NewClient(*target, grpc.WithTransportCredentials(creds))
+	if err != nil {
+		log.Fatalf("Failed to start NewClient: %v", err)
+	}
+	defer cc.Close()
+	c := pb.NewGreeterClient(cc)
+
+	// Make an RPC every second. This should trigger telemetry to be emitted from
+	// the client and the server.
+	for {
+		ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
+		r, err := c.SayHello(ctx, &pb.HelloRequest{Name: *name})
+		if err != nil {
+			log.Fatalf("Could not greet: %v", err)
+		}
+		fmt.Println(r)
+		time.Sleep(time.Second)
+		cancel()
+	}
+}

examples/features/csm_observability/server/Dockerfile

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+# Copyright 2024 gRPC 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.
+
+# Dockerfile for building the example server. To build the image, run the
+# following command from grpc-go directory:
+# docker build -t <TAG> -f examples/features/csm_observability/server/Dockerfile .
+
+FROM golang:1.25-alpine as build
+RUN apk --no-cache add curl
+# Make a grpc-go directory and copy the repo into it.
+WORKDIR /go/src/grpc-go
+COPY . .
+
+# Build a static binary without cgo so that we can copy just the binary in the
+# final image, and can get rid of the Go compiler and gRPC-Go dependencies.
+RUN cd examples/features/csm_observability/server && go build -tags osusergo,netgo .
+
+FROM alpine
+RUN apk --no-cache add curl
+COPY --from=build /go/src/grpc-go/examples/features/csm_observability/server/server .
+ENV GRPC_GO_LOG_VERBOSITY_LEVEL=99
+ENV GRPC_GO_LOG_SEVERITY_LEVEL="info"
+ENTRYPOINT ["./server"]

examples/features/csm_observability/server/main.go

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+/*
+ *
+ * Copyright 2024 gRPC 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.
+ *
+ */
+
+// Binary server is a server for the CSM Observability example.
+package main
+
+import (
+	"context"
+	"flag"
+	"log"
+	"net"
+	"net/http"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+	xdscreds "google.golang.org/grpc/credentials/xds"
+	pb "google.golang.org/grpc/examples/helloworld/helloworld"
+	"google.golang.org/grpc/stats/opentelemetry"
+	"google.golang.org/grpc/stats/opentelemetry/csm"
+	"google.golang.org/grpc/xds"
+
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"go.opentelemetry.io/otel/exporters/prometheus"
+	"go.opentelemetry.io/otel/sdk/metric"
+)
+
+var (
+	port               = flag.String("port", "50051", "the server address to connect to")
+	prometheusEndpoint = flag.String("prometheus_endpoint", ":9464", "the Prometheus exporter endpoint")
+)
+
+// server is used to implement helloworld.GreeterServer.
+type server struct {
+	pb.UnimplementedGreeterServer
+	addr string
+}
+
+// SayHello implements helloworld.GreeterServer
+func (s *server) SayHello(_ context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
+	return &pb.HelloReply{Message: "Hello " + in.GetName()}, nil
+}
+
+func main() {
+	flag.Parse()
+	exporter, err := prometheus.New()
+	if err != nil {
+		log.Fatalf("Failed to start prometheus exporter: %v", err)
+	}
+	provider := metric.NewMeterProvider(metric.WithReader(exporter))
+	go http.ListenAndServe(*prometheusEndpoint, promhttp.Handler())
+
+	cleanup := csm.EnableObservability(context.Background(), opentelemetry.Options{MetricsOptions: opentelemetry.MetricsOptions{MeterProvider: provider}})
+	defer cleanup()
+
+	lis, err := net.Listen("tcp4", "0.0.0.0:"+*port)
+	if err != nil {
+		log.Fatalf("Failed to listen: %v", err)
+	}
+	// Set up xds credentials that fall back to insecure as described in:
+	// https://cloud.google.com/service-mesh/docs/service-routing/security-proxyless-setup#workloads_are_unable_to_communicate_in_the_security_setup.
+	creds, err := xdscreds.NewServerCredentials(xdscreds.ServerOptions{FallbackCreds: insecure.NewCredentials()})
+	if err != nil {
+		log.Fatalf("Failed to create xDS credentials: %v", err)
+	}
+	s, err := xds.NewGRPCServer(grpc.Creds(creds))
+	if err != nil {
+		log.Fatalf("Failed to start xDS Server: %v", err)
+	}
+	pb.RegisterGreeterServer(s, &server{addr: ":" + *port})
+
+	log.Printf("Serving on %s\n", *port)
+
+	if err := s.Serve(lis); err != nil {
+		log.Fatalf("Failed to serve: %v", err)
+	}
+}