通过OpenTelemetry上报Go应用数据

下载最新版本的Golang Agent，并将对应架构的二进制包重命名为otel。

使用Golang Agent二进制编译。

参考文档，通过在go build指令之前添加编译前缀进行混合编译，例如：

otel go build -o app cmd/app

启动应用。

下述代码将直接运行您的应用并加载 OpenTelemetry Golang Agent，请将步骤一获取到的接入点信息替换到以下代码中，并将/path/to/your/app 替换为上一步使用Golang Agent编译出的二进制文件的实际路径。

export OTEL_LOGS_EXPORTER=none
export OTEL_RESOURCE_ATTRIBUTES=service.name=<service name>,service.version=<service version>,deployment.environment=<environment>
export OTEL_EXPORTER_OTLP_HEADERS="x-arms-license-key=<license-key>,x-arms-project=<arms-project>,x-cms-workspace=<workspace>"
export OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=<traces.endpoint>
export OTEL_EXPORTER_OTLP_METRICS_ENDPOINT=<metrics.endpoint>

/path/to/your/app

在 go mod 中添加如下依赖。

require (
	go.opentelemetry.io/otel v1.20.0
	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.20.0
	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.20.0
	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.20.0
	go.opentelemetry.io/otel/sdk v1.20.0
)

创建 OpenTelemetry 初始化工具代码.

新建 opentelemetry_util.go 文件，并添加以下代码。

package otel_util

import (
	"context"
	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/exporters/otlp/otlptrace"
    "go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp"
	"go.opentelemetry.io/otel/propagation"
	"go.opentelemetry.io/otel/sdk/resource"
	sdktrace "go.opentelemetry.io/otel/sdk/trace"
	semconv "go.opentelemetry.io/otel/semconv/v1.15.0"
	"google.golang.org/grpc"
	"google.golang.org/grpc/encoding/gzip"
	"log"
	"os"
	"time"
)

const (
	SERVICE_NAME       = "<service name>" // 应用名
	SERVICE_VERSION    = "<service version>" // 应用版本
	DEPLOY_ENVIRONMENT = "<environment>" // 部署环境
	HTTP_ENDPOINT      = "<endpoint>"  // 请将<endpoint>替换为步骤一中获取的接入点信息
	HTTP_URL_PATH      = "<url path>"  // 请将<url path>替换为步骤一中获取的接入点信息
)

// 设置应用资源
func newResource(ctx context.Context) *resource.Resource {
	hostName, _ := os.Hostname()

	r, err := resource.New(
		ctx,
		resource.WithFromEnv(),
		resource.WithProcess(),
		resource.WithTelemetrySDK(),
		resource.WithHost(),
		resource.WithAttributes(
			semconv.ServiceNameKey.String(SERVICE_NAME),
			semconv.ServiceVersionKey.String(SERVICE_VERSION),
			semconv.DeploymentEnvironmentKey.String(DEPLOY_ENVIRONMENT),
			semconv.HostNameKey.String(hostName), // 主机名
			attribute.String("acs.cms.workspace", WORK_SPACE), // Workspace名称
		),
	)

	if err != nil {
		log.Fatalf("%s: %v", "Failed to create OpenTelemetry resource", err)
	}
	return r
}

func newHTTPExporterAndSpanProcessor(ctx context.Context) (*otlptrace.Exporter, sdktrace.SpanProcessor) {
	headers := map[string]string{
	    "x-arms-license-key": "<license-key>", // 请将 <license-key> 替换为步骤一中获取的接入点信息
	    "x-arms-project": "<arms-project>", // 请将 <arms-project> 替换为步骤一中获取的接入点信息
	    "x-cms-workspace": "<workspace>", // 请将 <workspace> 替换为您的workspace名称
	}

	traceExporter, err := otlptrace.New(ctx, otlptracehttp.NewClient(
		otlptracehttp.WithEndpoint(HTTP_ENDPOINT),
		otlptracehttp.WithURLPath(HTTP_URL_PATH),
		otlptracehttp.WithHeaders(headers),
		otlptracehttp.WithCompression(1)))
	
	if err != nil {
		log.Fatalf("%s: %v", "Failed to create the OpenTelemetry trace exporter", err)
	}

	batchSpanProcessor := sdktrace.NewBatchSpanProcessor(traceExporter)

	return traceExporter, batchSpanProcessor
}

// InitOpenTelemetry OpenTelemetry 初始化方法
func InitOpenTelemetry() func() {
	ctx := context.Background()

	var traceExporter *otlptrace.Exporter
	var batchSpanProcessor sdktrace.SpanProcessor

	traceExporter, batchSpanProcessor = newHTTPExporterAndSpanProcessor(ctx)

	otelResource := newResource(ctx)

	traceProvider := sdktrace.NewTracerProvider(
		sdktrace.WithSampler(sdktrace.AlwaysSample()),
		sdktrace.WithResource(otelResource),
		sdktrace.WithSpanProcessor(batchSpanProcessor))

	otel.SetTracerProvider(traceProvider)
	otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}))

	return func() {
		cxt, cancel := context.WithTimeout(ctx, time.Second)
		defer cancel()
		if err := traceExporter.Shutdown(cxt); err != nil {
			otel.Handle(err)
		}
	}
}

创建 Span。

新建 main.go 文件，并添加以下代码。以下代码包含三个方法（除去main方法），每个方法均创建了一个 Span。

package main

import (
	"context"
	"fmt"
	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/codes"
	otel_util "otel_go_demo/util"
	"time"
)

func main() {
	shutdown := otel_util.InitOpenTelemetry()
	defer shutdown()

	for i:= 0; i < 10; i++ {
		ctx := context.Background()
		parentMethod(ctx)
	}
	time.Sleep(10 * time.Second)
}

func parentMethod(ctx context.Context) {
	tracer := otel.Tracer("otel-go-tracer")
	ctx, span := tracer.Start(ctx, "parent span")
	fmt.Println(span.SpanContext().TraceID()) // 打印 TraceId
	span.SetAttributes(attribute.String("key", "value"))
	span.SetStatus(codes.Ok, "Success")
	childMethod(ctx)
	span.End()
}

func childMethod(ctx context.Context) {
	tracer := otel.Tracer("otel-go-tracer")
	ctx, span := tracer.Start(ctx, "child span")
	span.SetStatus(codes.Ok, "Success")
	grandChildMethod(ctx)
	span.End()
}

func grandChildMethod(ctx context.Context) {
	tracer := otel.Tracer("otel-go-tracer")
	ctx, span := tracer.Start(ctx, "grandchild span")
	span.SetStatus(codes.Error, "error")

	// 业务代码...

	span.End()
}

运行程序以生成并上报 Trace 数据。

go run main.go