OpenTelemetry 项目使用介绍

func initProvider() (func(context.Context) error, error) {
    ctx := context.Background()

    // 1. 创建 Resource
    res, err := resource.New(
        ctx,
        resource.WithAttributes(
            // 用于后端调用链路中展示使用的服务名
            semconv.ServiceName("test-service"),
            ),
        )
    if err != nil {
        return nil, fmt.Errorf("failed to create resource: %w", err)
    }

    // 2. [可选]创建 gRPC 客户端，用于连接到 OpenTelemetry Collector
    conn, err := grpc.NewClient("localhost:4317",
            grpc.WithTransportCredentials(insecure.NewCredentials()),
           )
    if err != nil {
        return nil, fmt.Errorf("failed to create gRPC connection to collector: %w", err)
    }

    // 3. 配置链路数据的导出器，这里使用了 OpenTelemetry 提供的 OTLP gRPC 实现
    // 你也可以自己实现一个 Exporter 的扩展，从而用指定的协议上报到指定的代理或后端服务
    traceExporter, err := otlptracegrpc.New(context.Background(), otlptracegrpc.WithGRPCConn(conn))
    if err != nil {
        return nil, fmt.Errorf("failed to create trace exporter: %w", err)
    }

    // 4. 将导出器注册到 Span 的处理器中，并将采样器、资源和处理器注册到链路数据的提供者中
    bsp := sdktrace.NewBatchSpanProcessor(traceExporter)
    tracerProvider := sdktrace.NewTracerProvider(
        sdktrace.WithSampler(sdktrace.AlwaysSample()),
        sdktrace.WithResource(res),
        sdktrace.WithSpanProcessor(bsp),
    )

    // 5. 将链路数据提供者注册到全局
    otel.SetTracerProvider(tracerProvider)

    // 6. 将默认上下文传播器注册到全局
    otel.SetTextMapPropagator(propagation.TraceContext{})

    return tracerProvider.Shutdown, nil
}

func main() {
    log.Printf("Waiting for connection...")

    ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt)
    defer cancel()

    // 1. 初始化 provider
    shutdown, err := initProvider()
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        if err := shutdown(ctx); err != nil {
            log.Fatal("failed to shutdown TracerProvider: %w", err)
        }
    }()

    // 2. 获取 tracer
    tracer := otel.Tracer("test-tracer")

    // 3. 记录 Span 中的属性，这些属性可以被转为指标或者其他类型的遥测数据
    commonAttrs := []attribute.KeyValue{
        attribute.String("attrA", "chocolate"),
        attribute.String("attrB", "raspberry"),
        attribute.String("attrC", "vanilla"),
    }

    // 4. 执行业务逻辑，使用 Start 方法创建 Span，使用 End 方法关闭 Span
    // Span 会被 SDK 收集起来，调用导出器上报到代理或后端服务
    ctx, span := tracer.Start(
        ctx,
        "CollectorExporter-Example",
        trace.WithAttributes(commonAttrs...))
    defer span.End()
    for i := 0; i < 10; i++ {
        _, iSpan := tracer.Start(ctx, fmt.Sprintf("Sample-%d", i))
        log.Printf("Doing really hard work (%d / 10)\n", i+1)

        <-time.After(time.Second)
        iSpan.End()
    }

    log.Printf("Done!")
}

FROM eclipse-temurin:11-jre

ADD build/libs/app.jar /app.jar
ADD build/agent/opentelemetry-javaagent.jar /opentelemetry-javaagent.jar

ENTRYPOINT java -jar -javaagent:/opentelemetry-javaagent.jar /app.jar

version: '3'
services:
  app:
    build: ./
    environment:
      OTEL_SERVICE_NAME: "agent-example-app"
      OTEL_EXPORTER_OTLP_ENDPOINT: "http://localhost:4317"
      OTEL_LOGS_EXPORTER: "otlp"
      OTEL_CONFIG_FILE: "/sdk-config.yaml"
      OTEL_EXPORTER_OTLP_PROTOCOL: "grpc"
    ports:
      - "8080:8080"
    volumes:
      - ./sdk-config.yaml:/sdk-config.yaml
    depends_on:
      - otel-collector
  # 添加了 prometheus 和 jaeger 作为可观测后端服务
  otel-collector:
    image: otel/opentelemetry-collector-contrib:0.91.0
    command: ["--config=/etc/collector-config.yaml"]
    volumes:
      - ./collector-config.yaml:/etc/collector-config.yaml
    ports:
      - 4317:4317
    depends_on:
      - prometheus
      - jaeger

  prometheus:
    image: prom/prometheus:v2.45.2
    volumes:
      - ./prometheus.yaml:/etc/prometheus/prometheus.yml
    ports:
      - 9090:9090

  jaeger:
    image: jaegertracing/all-in-one:1.52
    ports:
      - 16686:16686

receivers:
  otlp:
    protocols:
      grpc:
        endpoint: 0.0.0.0:4317
processors:
extensions:
  health_check: {}
exporters:
  otlp:
    endpoint: jaeger:4317
    tls:
      insecure: true
  prometheus:
    endpoint: 0.0.0.0:9090
    namespace: testapp
  debug:

service:
  extensions: [health_check]
  pipelines:
    traces:
      receivers: [otlp]
      processors: []
      exporters: [otlp, debug]

    metrics:
      receivers: [otlp]
      processors: []
      exporters: [prometheus, debug]

    logs:
      receivers: [otlp]
      processors: []
      exporters: [debug]

scrape_configs:
  - job_name: 'otel-collector'
    scrape_interval: 5s
    static_configs:
      - targets: ['otel-collector:9090']