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

examples/features/csm_observability/client/main.go

@@ -0,0 +1,88 @@
+/*
+ *
+ * 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()
+	}
+}