1
import (
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    "go.opentelemetry.io/otel/trace"   // Tracer API
3
    "go.opentelemetry.io/otel/metric"  // Meter API
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    "go.opentelemetry.io/otel/log"     // Logger API（稳定化中）
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)
6

7
// 应用代码只使用 API，不关心后端实现
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func processOrder(ctx context.Context, order Order) error {
9
    // 追踪 API
10
    ctx, span := otel.Tracer("order-service").Start(ctx, "ProcessOrder")
11
    defer span.End()
12

13
    // 指标 API
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    requestCounter.Add(ctx, 1,
15
        metric.WithAttributes(semconv.HTTPMethodKey.String("POST")))
16

17
    // 日志 API
18
    logger.Info(ctx, "Order processed",
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        log.WithAttributes(log.String("order_id", order.ID)))
20

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    return nil
22
}

1
import (
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    "go.opentelemetry.io/otel/sdk/trace"
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    "go.opentelemetry.io/otel/sdk/metric"
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    "go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
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    "go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc"
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)
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func initOTel(ctx context.Context) (func(), error) {
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    // 创建 OTLP Exporter
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    traceExporter, err := otlptracegrpc.New(ctx,
11
        otlptracegrpc.WithEndpoint("otel-collector:4317"),
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        otlptracegrpc.WithInsecure(),
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    )
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    metricExporter, err := otlpmetricgrpc.New(ctx,
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        otlpmetricgrpc.WithEndpoint("otel-collector:4317"),
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        otlpmetricgrpc.WithInsecure(),
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    )
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    // 创建 TracerProvider
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    tp := trace.NewTracerProvider(
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        trace.WithBatcher(traceExporter,
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            trace.WithBatchTimeout(5*time.Second),
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            trace.WithMaxExportBatchSize(512),
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        ),
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        trace.WithResource(resource.NewWithAttributes(
27
            semconv.SchemaURL,
28
            semconv.ServiceNameKey.String("order-service"),
29
            semconv.ServiceVersionKey.String("v2.3.1"),
30
        )),
31
    )
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    otel.SetTracerProvider(tp)
33

34
    // 创建 MeterProvider
35
    mp, err := metric.NewMeterProvider(
36
        metric.WithReader(metric.NewPeriodicReader(metricExporter,
37
            metric.WithInterval(30*time.Second),
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        )),
39
    )
40
    otel.SetMeterProvider(mp)
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42
    return func() {
43
        tp.Shutdown(ctx)
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        mp.Shutdown(ctx)
45
    }, nil
46
}

1
# Kubernetes DaemonSet 部署
2
apiVersion: apps/v1
3
kind: DaemonSet
4
metadata:
5
  name: otel-collector-agent
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spec:
7
  selector:
8
    matchLabels:
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      app: otel-collector
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  template:
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    spec:
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      containers:
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        - name: otel-collector
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          image: otel/opentelemetry-collector-contrib:0.96.0
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          command: ["--config=/etc/otelcol/config.yaml"]
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          volumeMounts:
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            - name: config
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              mountPath: /etc/otelcol
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          resources:
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            limits:
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              memory: 512Mi
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              cpu: 200m
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            requests:
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              memory: 256Mi
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              cpu: 100m
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      volumes:
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        - name: config
28
          configMap:
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            name: otel-collector-config

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# 使用 otel-go 自动仪器化
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go get go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp
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go get go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc
4
go get go.opentelemetry.io/contrib/instrumentation/runtime
5

6
# HTTP 自动仪器化

1
import (
2
    "go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
3
)
4

5
func main() {
6
    // 包装 HTTP Handler，自动创建 Span
7
    handler := otelhttp.NewHandler(
8
        http.HandlerFunc(handleOrder),
9
        "order-handler",
10
        otelhttp.WithMessageEvents(otelhttp.Read, otelhttp.Write),
11
    )
12
    http.Handle("/api/v1/orders", handler)
13
    http.ListenAndServe(":8080", nil)
14
}

1
# 使用 OTel Java Agent（零代码修改）
2
java -javaagent:opentelemetry-javaagent.jar \
3
     -Dotel.service.name=order-service \
4
     -Dotel.exporter.otlp.endpoint=http://otel-collector:4317 \
5
     -Dotel.instrumentation.common.enabled=true \
6
     -jar my-app.jar

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# 使用 OTel Python 自动仪器化
2
from opentelemetry.instrumentation.auto_instrumentation import sitecustomize
3

4
# 或手动初始化
5
from opentelemetry.instrumentation.flask import FlaskInstrumentor
6
from opentelemetry.instrumentation.requests import RequestsInstrumentor
7
from opentelemetry.instrumentation.sqlalchemy import SQLAlchemyInstrumentor
8

9
FlaskInstrumentor().instrument()
10
RequestsInstrumentor().instrument()
11
SQLAlchemyInstrumentor().instrument()

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// 简化的 OTLP 数据模型
2
message ExportTraceServiceRequest {
3
  repeated ResourceSpans resource_spans = 1;
4
}
5

6
message ResourceSpans {
7
  Resource resource = 1;
8
  repeated ScopeSpans scope_spans = 2;
9
}
10

11
message ScopeSpans {
12
  InstrumentationScope scope = 1;
13
  repeated Span spans = 2;
14
}
15

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message Span {
17
  string trace_id = 1;
18
  string span_id = 2;
19
  string parent_span_id = 3;
20
  string name = 4;
21
  SpanKind kind = 5;
22
  fixed64 start_time_unix_nano = 6;
23
  fixed64 end_time_unix_nano = 7;
24
  repeated KeyValue attributes = 8;
25
  SpanStatus status = 9;
26
  repeated Event events = 10;
27
  repeated Link links = 11;
28
}

1
// 使用语义约定
2
span.SetAttributes(
3
    semconv.HTTPMethodKey.String("GET"),
4
    semconv.HTTPStatusCodeKey.Int(200),
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    semconv.HTTPRouteKey.String("/api/v1/orders"),
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    semconv.DBSystemKey.String("postgresql"),
7
    semconv.DBOperationKey.String("SELECT"),
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)
9

10
// 自定义属性名（不一致）
11
span.SetAttributes(
12
    attribute.String("method", "GET"),
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    attribute.Int("status", 200),
14
    attribute.String("route", "/api/v1/orders"),
15
    attribute.String("db", "pg"),
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    attribute.String("op", "select"),
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)

1
docker compose up -d otel-collector
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3
# 验证 Collector 运行
4
curl http://localhost:13133/

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# 发送追踪 → Collector → Tempo
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curl -X POST http://localhost:4318/v1/traces \
3
  -H "Content-Type: application/json" \
4
  -d '{"resourceSpans":[{"resource":{"attributes":[{"key":"service.name","value":{"stringValue":"test"}}]},"scopeSpans":[{"spans":[{"traceId":"01234567890123456789012345678901","spanId":"0123456789012345","name":"test","kind":1,"startTimeUnixNano":"1700000000000000000","endTimeUnixNano":"1700000001000000000"}]}]}]}'
5

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# 发送指标 → Collector → Prometheus
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curl -X POST http://localhost:4318/v1/metrics \
8
  -H "Content-Type: application/json" \
9
  -d '{"resourceMetrics":[{"resource":{"attributes":[{"key":"service.name","value":{"stringValue":"test"}}]},"scopeMetrics":[{"metrics":[{"name":"test.counter","gauge":{"dataPoints":[{"asDouble":1,"timeUnixNano":"1700000000000000000"}]}}]}]}]}'
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# 发送日志 → Collector → Loki
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curl -X POST http://localhost:4318/v1/logs \
13
  -H "Content-Type: application/json" \
14
  -d '{"resourceLogs":[{"resource":{"attributes":[{"key":"service.name","value":{"stringValue":"test"}}]},"scopeLogs":[{"logRecords":[{"timeUnixNano":"1700000000000000000","severityNumber":9,"body":{"stringValue":"Test log message"}}]}]}]}'