Add gRPC examples with OTLP SDK

.gitignore

@@ -13,5 +13,7 @@ coverage.*
 /example/metric/collector/collector
 /example/metric/sdk/metrics
 /example/metric/sdk/sdk
+/example/metric/otlpgrpc/otlpgrpc
+/example/trace/otlpgrpc/otlpgrpc
 go.work
 go.work.sum

example/metric/otlpgrpc/example.go

@@ -0,0 +1,83 @@
+// Copyright 2024 Google LLC
+//
+// 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.
+
+package main
+
+import (
+	"context"
+	"log"
+
+	"go.opentelemetry.io/contrib/detectors/gcp"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc"
+	"go.opentelemetry.io/otel/metric"
+	sdkmetric "go.opentelemetry.io/otel/sdk/metric"
+	"go.opentelemetry.io/otel/sdk/resource"
+	semconv "go.opentelemetry.io/otel/semconv/v1.21.0"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/oauth"
+)
+
+func main() {
+	ctx := context.Background()
+
+	creds, err := oauth.NewApplicationDefault(ctx)
+	if err != nil {
+		panic(err)
+	}
+
+	res, err := resource.New(
+		ctx,
+		// Use the GCP resource detector to detect information about the GCP platform
+		resource.WithDetectors(gcp.NewDetector()),
+		// Keep the default detectors
+		resource.WithTelemetrySDK(),
+		// Add attributes from environment variables
+		resource.WithFromEnv(),
+		// Add your own custom attributes to identify your application
+		resource.WithAttributes(
+			semconv.ServiceNameKey.String("example-application"),
+		),
+	)
+	if err != nil {
+		panic(err)
+	}
+
+	// Set endpoint with OTEL_EXPORTER_OTLP_ENDPOINT or OTEL_EXPORTER_OTLP_METRICS_ENDPOINT
+	metricExporter, err := otlpmetricgrpc.New(ctx, otlpmetricgrpc.WithDialOption(grpc.WithPerRPCCredentials(creds)))
+	if err != nil {
+		panic(err)
+	}
+
+	meterProvider := sdkmetric.NewMeterProvider(
+		sdkmetric.WithResource(res),
+		sdkmetric.WithReader(sdkmetric.NewPeriodicReader(metricExporter)),
+	)
+
+	defer func() {
+		if err = meterProvider.Shutdown(ctx); err != nil {
+			log.Println(err)
+		}
+	}()
+
+	meter := meterProvider.Meter("github.com/GoogleCloudPlatform/opentelemetry-operations-go/example/metric/otlpgrpc")
+
+	// Register counter value
+	counter, err := meter.Int64Counter("counter-a")
+	if err != nil {
+		log.Fatalf("Failed to create counter: %v", err)
+	}
+	clabels := []attribute.KeyValue{attribute.Key("key").String("value")}
+	counter.Add(ctx, 100, metric.WithAttributes(clabels...))
+}

example/metric/otlpgrpc/go.mod

@@ -0,0 +1,34 @@
+module github.com/GoogleCloudPlatform/opentelemetry-operations-go/example/metric/otlpgrpc
+
+go 1.21
+
+require (
+	go.opentelemetry.io/contrib/detectors/gcp v1.23.0
+	go.opentelemetry.io/otel v1.23.0
+	go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc v1.23.0
+	go.opentelemetry.io/otel/metric v1.23.0
+	go.opentelemetry.io/otel/sdk v1.23.0
+	go.opentelemetry.io/otel/sdk/metric v1.23.0
+	google.golang.org/grpc v1.61.0
+)
+
+require (
+	cloud.google.com/go/compute v1.23.3 // indirect
+	cloud.google.com/go/compute/metadata v0.2.3 // indirect
+	github.com/GoogleCloudPlatform/opentelemetry-operations-go/detectors/gcp v1.21.0 // indirect
+	github.com/cenkalti/backoff/v4 v4.2.1 // indirect
+	github.com/go-logr/logr v1.4.1 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.19.0 // indirect
+	go.opentelemetry.io/otel/trace v1.23.0 // indirect
+	go.opentelemetry.io/proto/otlp v1.1.0 // indirect
+	golang.org/x/net v0.19.0 // indirect
+	golang.org/x/oauth2 v0.15.0 // indirect
+	golang.org/x/sys v0.16.0 // indirect
+	golang.org/x/text v0.14.0 // indirect
+	google.golang.org/appengine v1.6.8 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20240102182953-50ed04b92917 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20240102182953-50ed04b92917 // indirect
+	google.golang.org/protobuf v1.32.0 // indirect
+)

example/metric/otlpgrpc/go.sum

@@ -0,0 +1,93 @@
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+cloud.google.com/go/compute v1.23.3/go.mod h1:VCgBUoMnIVIR0CscqQiPJLAG25E3ZRZMzcFZeQ+h8CI=
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example/trace/otlpgrpc/example.go

@@ -0,0 +1,77 @@
+// Copyright 2019 OpenTelemetry Authors
+// Copyright 2024 Google LLC
+//
+// 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.
+
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"time"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+	semconv "go.opentelemetry.io/otel/semconv/v1.24.0"
+	"go.opentelemetry.io/otel/trace"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/oauth"
+)
+
+func initTracer() (func(), error) {
+	ctx := context.Background()
+
+	creds, err := oauth.NewApplicationDefault(ctx)
+	if err != nil {
+		panic(err)
+	}
+
+	exporter, err := otlptracegrpc.New(ctx, otlptracegrpc.WithDialOption(grpc.WithPerRPCCredentials(creds)))
+	if err != nil {
+		panic(err)
+	}
+
+	tp := sdktrace.NewTracerProvider(
+		// For this example code we use sdktrace.AlwaysSample sampler to sample all traces.
+		// In a production application, use sdktrace.ProbabilitySampler with a desired probability.
+		sdktrace.WithSampler(sdktrace.AlwaysSample()),
+		sdktrace.WithBatcher(exporter))
+
+	otel.SetTracerProvider(tp)
+	return func() {
+		err := tp.Shutdown(context.Background())
+		if err != nil {
+			fmt.Printf("error shutting down trace provider: %+v", err)
+		}
+	}, nil
+}
+
+func main() {
+	shutdown, err := initTracer()
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer shutdown()
+	tr := otel.Tracer("cloudtrace/example/client")
+
+	ctx := context.Background()
+	fmt.Println("starting span...")
+	_, span := tr.Start(ctx, "test span", trace.WithAttributes(semconv.PeerServiceKey.String("ExampleService")))
+	defer span.End()
+	defer fmt.Println("ending span.")
+
+	time.Sleep(3 * time.Second)
+}

example/trace/otlpgrpc/go.mod

@@ -0,0 +1,32 @@
+module github.com/GoogleCloudPlatform/opentelemetry-operations-go/example/trace/otlpgrpc
+
+go 1.21
+
+require (
+	go.opentelemetry.io/otel v1.23.1
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.23.1
+	go.opentelemetry.io/otel/sdk v1.23.1
+	go.opentelemetry.io/otel/trace v1.23.1
+	google.golang.org/grpc v1.61.0
+)
+
+require (
+	cloud.google.com/go/compute v1.23.3 // indirect
+	cloud.google.com/go/compute/metadata v0.2.3 // indirect
+	github.com/cenkalti/backoff/v4 v4.2.1 // indirect
+	github.com/go-logr/logr v1.4.1 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.19.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.23.1 // indirect
+	go.opentelemetry.io/otel/metric v1.23.1 // indirect
+	go.opentelemetry.io/proto/otlp v1.1.0 // indirect
+	golang.org/x/net v0.19.0 // indirect
+	golang.org/x/oauth2 v0.15.0 // indirect
+	golang.org/x/sys v0.16.0 // indirect
+	golang.org/x/text v0.14.0 // indirect
+	google.golang.org/appengine v1.6.8 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20240102182953-50ed04b92917 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20240102182953-50ed04b92917 // indirect
+	google.golang.org/protobuf v1.32.0 // indirect
+)