SDK を使用してアプリケーションから指標を送信する

このドキュメントでは、SDK と gRPC エクスポータ（SDK での使用が推奨されるエクスポータ）を使用して、アプリケーションから OTLP エンドポイントに指標を直接送信する方法について説明します。OTLP エンドポイントは、http/proto、http/json、grpc などのすべての OTLP プロトコルをサポートしています。詳細については、プロトコルのサポートをご覧ください。

アプリケーション指標を OTLP エンドポイントに直接送信する場合、OpenTelemetry Collector は認証と拡充を処理しません。SDK を使用してアプリケーションから指標を送信する場合は、次の操作を行う必要があります。

始める前に

例を実行するには、必要な API を有効にして、認証情報を取得する必要があります。

API を有効にする

次のコマンドを実行して、Google Cloud プロジェクトで Cloud Monitoring API と Telemetry API を有効にします。

gcloud services enable monitoring.googleapis.com telemetry.googleapis.com

認証情報を取得する

次のコマンドを実行して、OTLP gRPC エクスポーターが Google アプリケーションのデフォルト認証情報を使用するように認証情報を構成します。

gcloud auth application-default login

言語固有の例

このセクションでは、カウンタ指標を作成して書き込む言語固有のサンプルをいくつか紹介します。サンプルを実行してコードを表示する方法については、タブを選択してください。

Go

この例の構成と実行については、Go サンプルの README ファイルをご覧ください。

// 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"
	"errors"
	"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/v1.37.0"
	"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 errors.Is(err, resource.ErrPartialResource) || errors.Is(err, resource.ErrSchemaURLConflict) {
		log.Println(err)
	} else 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...))
}

Java

この例の構成と実行については、Java サンプルの README ファイルをご覧ください。

/*
 * Copyright 2025 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 com.google.cloud.opentelemetry.example.otlpmetric;

import com.google.auth.oauth2.GoogleCredentials;
import io.opentelemetry.api.metrics.LongCounter;
import io.opentelemetry.exporter.otlp.http.metrics.OtlpHttpMetricExporter;
import io.opentelemetry.exporter.otlp.metrics.OtlpGrpcMetricExporter;
import io.opentelemetry.sdk.OpenTelemetrySdk;
import io.opentelemetry.sdk.autoconfigure.AutoConfiguredOpenTelemetrySdk;
import io.opentelemetry.sdk.common.CompletableResultCode;
import io.opentelemetry.sdk.metrics.export.MetricExporter;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
import java.util.concurrent.TimeUnit;

public class OTLPMetricExample {
  private static final String INSTRUMENTATION_SCOPE_NAME = OTLPMetricExample.class.getName();
  private static final Random RANDOM = new Random();

  private static OpenTelemetrySdk openTelemetrySdk;

  private static OpenTelemetrySdk setupMetricExporter() throws IOException {
    GoogleCredentials credentials = GoogleCredentials.getApplicationDefault();

    // Update the SDK configured using environment variables and system properties
    // TODO: Replace this with the use of gcp-auth-extension
    AutoConfiguredOpenTelemetrySdk autoConfOTelSdk =
        AutoConfiguredOpenTelemetrySdk.builder()
            .addMetricExporterCustomizer(
                (exporter, configProperties) -> addAuthorizationHeaders(exporter, credentials))
            .build();
    return autoConfOTelSdk.getOpenTelemetrySdk();
  }

  // Modifies the metric exporter initially auto-configured using environment variables
  // This will invoke the header supplier function to compute the headers, which takes care of the
  // refresh.
  private static MetricExporter addAuthorizationHeaders(
      MetricExporter exporter, GoogleCredentials credentials) {
    if (exporter instanceof OtlpHttpMetricExporter) {
      return ((OtlpHttpMetricExporter) exporter)
          .toBuilder().setHeaders(() -> getRequiredHeaderMap(credentials)).build();
    } else if (exporter instanceof OtlpGrpcMetricExporter) {
      return ((OtlpGrpcMetricExporter) exporter)
          .toBuilder().setHeaders(() -> getRequiredHeaderMap(credentials)).build();
    }
    return exporter;
  }

  private static Map<String, String> getRequiredHeaderMap(GoogleCredentials credentials) {
    Map<String, String> gcpHeaders = new HashMap<>();
    try {
      credentials.refreshIfExpired();
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
    gcpHeaders.put("Authorization", "Bearer " + credentials.getAccessToken().getTokenValue());
    String configuredQuotaProjectId = credentials.getQuotaProjectId();
    if (configuredQuotaProjectId != null && !configuredQuotaProjectId.isEmpty()) {
      gcpHeaders.put("x-goog-user-project", configuredQuotaProjectId);
    }
    return gcpHeaders;
  }

  private static void myUseCase() {
    LongCounter counter =
        openTelemetrySdk
            .getMeter(INSTRUMENTATION_SCOPE_NAME)
            .counterBuilder("example_counter")
            .setDescription("Processed jobs")
            .setUnit("1")
            .build();
    doWork(counter);
  }

  private static void doWork(LongCounter counter) {
    try {
      for (int i = 0; i < 10; i++) {
        counter.add(RANDOM.nextInt(100));
        Thread.sleep(RANDOM.nextInt(1000));
      }
    } catch (InterruptedException e) {
      throw new RuntimeException(e);
    }
  }

  public static void main(String[] args) throws IOException {
    // Configure the OpenTelemetry pipeline with CloudMetric exporter
    openTelemetrySdk = setupMetricExporter();

    // Application-specific logic
    myUseCase();

    // Flush all buffered metrics
    CompletableResultCode completableResultCode = openTelemetrySdk.getSdkMeterProvider().shutdown();
    // wait till export finishes
    completableResultCode.join(10000, TimeUnit.MILLISECONDS);
  }
}

NodeJS

この例の構成と実行については、NodeJS サンプルの README ファイルをご覧ください。

// Copyright 2025 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
//
//      https://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.

import * as opentelemetry from '@opentelemetry/sdk-node';
import {AuthClient, GoogleAuth} from 'google-auth-library';
import {credentials} from '@grpc/grpc-js';
import {getResourceDetectors as getResourceDetectorsFromEnv} from '@opentelemetry/auto-instrumentations-node';
import {metrics, diag, DiagConsoleLogger} from '@opentelemetry/api';
import {OTLPMetricExporter} from '@opentelemetry/exporter-metrics-otlp-grpc';
import {PeriodicExportingMetricReader} from '@opentelemetry/sdk-metrics';

async function getAuthenticatedClient(): Promise<AuthClient> {
  const auth: GoogleAuth = new GoogleAuth({
    scopes: 'https://www.googleapis.com/auth/cloud-platform',
  });
  return await auth.getClient();
}

diag.setLogger(
  new DiagConsoleLogger(),
  opentelemetry.core.diagLogLevelFromString(
    opentelemetry.core.getStringFromEnv('OTEL_LOG_LEVEL'),
  ),
);

// App that exports metrics via gRPC with protobuf
async function main() {
  const authenticatedClient: AuthClient = await getAuthenticatedClient();

  const sdk = new opentelemetry.NodeSDK({
    metricReader: new PeriodicExportingMetricReader({
      // Export metrics every 10 seconds. 5 seconds is the smallest sample period allowed by
      // Cloud Monitoring.
      exportIntervalMillis: 10_000,
      exporter: new OTLPMetricExporter({
        credentials: credentials.combineChannelCredentials(
          credentials.createSsl(),
          credentials.createFromGoogleCredential(authenticatedClient),
        ),
      }),
    }),
    resourceDetectors: getResourceDetectorsFromEnv(),
  });
  sdk.start();

  // Create a meter
  const meter = metrics.getMeter('metrics-sample');

  // Create a counter instrument
  const counter = meter.createCounter('metric_name');
  // Record a measurement
  counter.add(10, {key: 'value'});

  // Wait for the metric to be exported
  await new Promise(resolve => {
    setTimeout(resolve, 11_000);
  });

  // Gracefully shut down the SDK to flush telemetry when the program exits
  process.on('SIGTERM', () => {
    sdk
      .shutdown()
      .then(() => diag.debug('OpenTelemetry SDK terminated'))
      .catch(error => diag.error('Error terminating OpenTelemetry SDK', error));
  });
}

main().catch(console.error);

Python

この例の実行については、Python サンプルの README ファイルをご覧ください。README

#!/usr/bin/env python3
# Copyright 2025 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.

import time

import google.auth
import google.auth.transport.grpc
import google.auth.transport.requests
import grpc
from google.auth.transport.grpc import AuthMetadataPlugin
from opentelemetry.exporter.otlp.proto.grpc.metric_exporter import (
    OTLPMetricExporter,
)
from opentelemetry.resourcedetector.gcp_resource_detector import GoogleCloudResourceDetector
from opentelemetry.sdk.resources import get_aggregated_resources
from opentelemetry.sdk.metrics import MeterProvider
from opentelemetry.sdk.metrics.export import PeriodicExportingMetricReader

"""
This is a sample script that exports OTLP metrics encoded as protobufs via gRPC. 
"""

credentials, project_id = google.auth.default()
request = google.auth.transport.requests.Request()
resource = get_aggregated_resources(
    [GoogleCloudResourceDetector(raise_on_error=True)]
)

auth_metadata_plugin = AuthMetadataPlugin(
    credentials=credentials, request=request
)
channel_creds = grpc.composite_channel_credentials(
    grpc.ssl_channel_credentials(),
    grpc.metadata_call_credentials(auth_metadata_plugin),
)

exporter = OTLPMetricExporter(credentials=channel_creds)
reader = PeriodicExportingMetricReader(exporter)
provider = MeterProvider(metric_readers=[reader],resource=resource)
meter = provider.get_meter("gcp.otlp.sample")
counter = meter.create_counter("sample.otlp.counter")


def do_work():
    counter.add(1)
    # do some work that the 'counter' will track
    print("doing some work...")


def do_work_repeatedly():
    try:
        while True:
            do_work()
            time.sleep(1)
    except KeyboardInterrupt:
        print("\nKeyboard Interrupt: Stopping work.")


do_work_repeatedly()

Pod として実行されているアプリケーションに Downward API を使用する

Kubernetes でアプリケーションを Pod として実行していて、OpenTelemetry Collector を介して送信していない場合は、下向き API を使用して Kubernetes リソース属性を設定してください。

env:
- name: POD_NAME
  valueFrom:
    fieldRef:
      fieldPath: metadata.name
- name: NAMESPACE_NAME
  valueFrom:
    fieldRef:
      fieldPath: metadata.namespace
- name: CONTAINER_NAME
  value: my-container-name
- name: OTEL_RESOURCE_ATTRIBUTES
  value: k8s.pod.name=$(POD_NAME),k8s.namespace.name=$(NAMESPACE_NAME),k8s.container.name=$(CONTAINER_NAME)

次のステップ