Simple Log Service:Import trace data from Golang applications to Simple Log Service by using OpenTelemetry SDK for Golang

Procedure

1. Initialize an OpenTelemetry provider.

2. Check whether the conditions for importing data in semi-automatic mode are met.

   • If the conditions are met, you can import trace data in semi-automatic mode.

     If the semi-automatic mode does not meet your requirements, you must manually import the trace data.

   • If the conditions are not met, you can import trace data in manual mode.

Step 1: Initialize an OpenTelemetry provider

Step 2: Import data

• Semi-automatic mode: recommended

  OpenTelemetry provides automatic instrumentation solutions for various basic libraries. If your business rely on these libraries, you can use the automatic instrumentation solutions to import data. For more information about basic libraries, see Instrumentation.

  • Use the .NET or HTTP framework to import data

    The following sample code is created based on go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.37.0. For more information, see otel-http-example.

    Replace the variables in the following code with the actual values. For more information about the variables, see Variables.

    package main
    
    import (
        "fmt"
        "go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
        "go.opentelemetry.io/otel/attribute"
        "go.opentelemetry.io/otel/metric/global"
        "io"
        "net/http"
        "time"
    
        "github.com/aliyun-sls/opentelemetry-go-provider-sls/provider"
    
        "go.opentelemetry.io/otel/trace"
    )
    
    func main() {
    
        slsConfig, err := provider.NewConfig(provider.WithServiceName("${service}"),
            provider.WithServiceNamespace("${service.namespace}"),
            provider.WithServiceVersion("${version}"),
            provider.WithTraceExporterEndpoint("${endpoint}"),
            provider.WithMetricExporterEndpoint("${endpoint}"),
            provider.WithSLSConfig("${project}", "${instance}", "${access-key-id}", "${access-key-secret}"))
        // Invoke the panic() function. If the initialization fails, the OpenTelemetry provider exits. You can also use other error handling methods. 
        if err != nil {
            panic(err)
        }
        if err := provider.Start(slsConfig); err != nil {
            panic(err)
        }
        defer provider.Shutdown(slsConfig)
    
        // If you want to analyze metric data in the application, you can register the metrics. 
        labels := []attribute.KeyValue{
            attribute.String("label1", "value1"),
        }
        meter := global.Meter("aliyun.sls")
        sayDavidCount, _ := meter.Int64Counter("say_david_count")
    
        helloHandler := func(w http.ResponseWriter, req *http.Request) {
            if time.Now().Unix()%10 == 0 {
                _, _ = io.WriteString(w, "Hello, world!\n")
            } else {
                // If you want to record some events, you can obtain the span in the context and add events. 
                ctx := req.Context()
                span := trace.SpanFromContext(ctx)
                span.AddEvent("say : Hello, I am david", trace.WithAttributes(attribute.KeyValue{
                    Key:   "label-key-1",
                    Value: attribute.StringValue("label-value-1"),
                }))
    
                _, _ = io.WriteString(w, "Hello, I am david!\n")
                sayDavidCount.Add(req.Context(), 1, labels...)
            }
        }
    
        // To use the automatic instrumentation solution for otel net/http, you need to only wrap http.Handler with otelhttp.NewHandler. 
        otelHandler := otelhttp.NewHandler(http.HandlerFunc(helloHandler), "Hello")
    
        http.Handle("/hello", otelHandler)
        fmt.Println("Now listen port 8080, you can visit 127.0.0.1:8080/hello .")
        err = http.ListenAndServe(":8080", nil)
        if err != nil {
            panic(err)
        }
    }
                                

  • Use the Gorilla Mux framework to import data

    The following sample code is created based on go.opentelemetry.io/contrib/instrumentation/github.com/gorilla/mux/otelmux v0.37.0. The interface may change in later versions. For more information about the latest sample code, see otel-mux-example.

    Replace the variables in the following code with the actual values. For more information about the variables, see Variables.

    package main
    
    import (
        "context"
        "fmt"
        "go.opentelemetry.io/otel/attribute"
        "go.opentelemetry.io/otel/metric/global"
        "net/http"
    
        "github.com/aliyun-sls/opentelemetry-go-provider-sls/provider"
    
        "github.com/gorilla/mux"
        "go.opentelemetry.io/contrib/instrumentation/github.com/gorilla/mux/otelmux"
        "go.opentelemetry.io/otel/trace"
    )
    
    func main() {
    
        slsConfig, err := provider.NewConfig(provider.WithServiceName("${service}"),
            provider.WithServiceNamespace("${service.namespace}"),
            provider.WithServiceVersion("${version}"),
            provider.WithTraceExporterEndpoint("${endpoint}"),
            provider.WithMetricExporterEndpoint("${endpoint}"),
            provider.WithSLSConfig("${project}", "${instance}", "${access-key-id}", "${access-key-secret}"))
        // Invoke the panic() function. If the initialization fails, the OpenTelemetry provider exits. You can also use other error handling methods. 
        if err != nil {
            panic(err)
        }
        if err := provider.Start(slsConfig); err != nil {
            panic(err)
        }
        defer provider.Shutdown(slsConfig)
    
        // If you want to analyze metric data in the application, you can register the metrics. 
        labels := []attribute.KeyValue{
            attribute.String("label1", "value1"),
        }
        meter := global.Meter("aliyun.sls")
        callUsersCount, _ := meter.Int64Counter("call_users_count")
    
        r := mux.NewRouter()
        r.Use(otelmux.Middleware("my-server"))
        r.HandleFunc("/users/{id:[0-9]+}", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
            vars := mux.Vars(r)
            id := vars["id"]
            callUsersCount.Add(r.Context(), 1, labels...)
            name := getUser(r.Context(), id)
            reply := fmt.Sprintf("user %s (id %s)\n", name, id)
            _, _ = w.Write(([]byte)(reply))
        }))
        http.Handle("/", r)
        fmt.Println("Now listen port 8080, you can visit 127.0.0.1:8080/users/xxx .")
        _ = http.ListenAndServe(":8080", nil)
    }
    
    func getUser(ctx context.Context, id string) string {
        if id == "123" {
            return "otelmux tester"
        }
        // If you want to record some events, you can obtain the span in the context and add events. 
        span := trace.SpanFromContext(ctx)
        span.AddEvent("unknown user id : "+id, trace.WithAttributes(attribute.KeyValue{
            Key:   "label-key-1",
            Value: attribute.StringValue("label-value-1"),
        }))
        return "unknown"
    }
                                

• Manual mode

  Replace the variables in the following code with the actual values. For more information about the variables, see Variables.

  // Copyright The AliyunSLS Authors
  //
  // 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"
      "fmt"
      "go.opentelemetry.io/otel/attribute"
      "go.opentelemetry.io/otel/metric/global"
      "go.opentelemetry.io/otel/metric/instrument"
      "math/rand"
      "time"
  
      "github.com/aliyun-sls/opentelemetry-go-provider-sls/provider"
  
      "go.opentelemetry.io/otel"
      "go.opentelemetry.io/otel/codes"
      "go.opentelemetry.io/otel/trace"
  )
  
  func main() {
      slsConfig, err := provider.NewConfig(provider.WithServiceName("payment"),
          provider.WithServiceVersion("v0.1.0"),
          provider.WithTraceExporterEndpoint("stdout"),
          provider.WithMetricExporterEndpoint("stdout"),
          provider.WithSLSConfig("test-project", "test-otel", "access-key-id", "access-key-secret"))
      // Invoke the panic() function. If the initialization fails, the OpenTelemetry provider exits. You can also use other error handling methods. 
      if err != nil {
          panic(err)
      }
      if err := provider.Start(slsConfig); err != nil {
          panic(err)
      }
      defer provider.Shutdown(slsConfig)
  
      mockTrace()
      mockMetrics()
  }
  
  func mockMetrics() {
      // Add the label information. 
      labels := []attribute.KeyValue{
          attribute.String("label1", "value1"),
      }
  
      meter := global.Meter("ex.com/basic")
  
      meter.Float64ObservableCounter("randval", instrument.WithFloat64Callback(func(ctx context.Context, observer instrument.Float64Observer) error {
          observer.Observe(rand.Float64(), labels...)
          return nil
      }))
  
      temperature, _ := meter.Float64Counter("temperature")
      interrupts, _ := meter.Int64Counter("interrupts")
  
      ctx := context.Background()
  
      for {
          temperature.Add(ctx, 100+10*rand.NormFloat64(), labels...)
          interrupts.Add(ctx, int64(rand.Intn(100)), labels...)
  
          time.Sleep(time.Second * time.Duration(rand.Intn(10)))
      }
  }
  
  func mockTrace() {
  
      tracer := otel.Tracer("ex.com/basic")
  
      ctx0 := context.Background()
  
      ctx1, finish1 := tracer.Start(ctx0, "foo")
      defer finish1.End()
  
      ctx2, finish2 := tracer.Start(ctx1, "bar")
      defer finish2.End()
  
      ctx3, finish3 := tracer.Start(ctx2, "baz")
      defer finish3.End()
  
      ctx := ctx3
      getSpan(ctx)
      addAttribute(ctx)
      addEvent(ctx)
      recordException(ctx)
      createChild(ctx, tracer)
  }
  
  // example of getting the current span
  // Obtain the current span. 
  func getSpan(ctx context.Context) {
      span := trace.SpanFromContext(ctx)
      fmt.Printf("current span: %v\n", span)
  }
  
  // example of adding an attribute to a span
  // Add an attribute value to the span. 
  func addAttribute(ctx context.Context) {
      span := trace.SpanFromContext(ctx)
      span.SetAttributes(attribute.KeyValue{
          Key:   "label-key-1",
          Value: attribute.StringValue("label-value-1")})
  }
  
  // example of adding an event to a span
  // Add an event to the span. 
  func addEvent(ctx context.Context) {
      span := trace.SpanFromContext(ctx)
      span.AddEvent("event1", trace.WithAttributes(
          attribute.String("event-attr1", "event-string1"),
          attribute.Int64("event-attr2", 10)))
  }
  
  // example of recording an exception
  // Record the result of the span and the error information. 
  func recordException(ctx context.Context) {
      span := trace.SpanFromContext(ctx)
      span.RecordError(errors.New("exception has occurred"))
      span.SetStatus(codes.Error, "internal error")
  }
  
  // example of creating a child span
  // Create a child span. 
  func createChild(ctx context.Context, tracer trace.Tracer) {
      // span := trace.SpanFromContext(ctx)
      _, childSpan := tracer.Start(ctx, "child")
      defer childSpan.End()
      fmt.Printf("child span: %v\n", childSpan)
  }