Instrument Go applications with OpenTelemetry

To take advantage of the available instrumentation packages, go to the OpenTelemetry repository, find the package that your app is using, and install it using the following command:

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go get go.opentelemetry.io/contrib/instrumentation/<IMPORT_PATH>/otel<PACKAGE_NAME>

Where the <IMPORT_PATH> and <PACKAGE_NAME> are the standard Go identifiers for the package being instrumented.

• Install the dependency:

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go get go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp

• Add the import to your code:

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"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"

• Wrap your HTTP handler with otelhttp:

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handler := http.HandlerFunc(httpHandler)
wrappedHandler := otelhttp.NewHandler(handler, "my-span") //TODO Replace with the name of your span

//Use the wrappedHandler with your handle
http.Handle("/", wrappedHandler)

To instrument manually, install the packages below and add the code snippet below to any Go function you want to monitor. Set names for the tracer and the span, and add attributes as you see fit.

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go get go.opentelemetry.io/otel@v1.11.2
go get go.opentelemetry.io/otel/sdk@v1.11.2

• Add the following imports to your code:

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"go.opentelemetry.io/otel"
"go.opentelemetry.io/otel/attribute"
"go.opentelemetry.io/otel/codes"
sdktrace "go.opentelemetry.io/otel/sdk/trace"

• Set the TracerProvider within your main function:

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otel.SetTracerProvider(sdktrace.NewTracerProvider())

• And finally, add the span to the function you would like to instrument:

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_, span := otel.Tracer("my-tracer").Start(context.Background(), "my-span") //TODO Add names for tracer and span
span.SetAttributes(
    attribute.String("my-key-1", "my-value-1"))//TODO Add attributes

defer span.End()

//TODO your code goes here

// Set the status of your span if there is a possible error
if err != nil {
    span.SetStatus(codes.Error, err.Error())
}
span.SetStatus(codes.Ok, "successful")

OneAgent can only instrument a tracer implementation of the default OpenTelemetry SDK. If you have not already installed the OpenTelemetry SDK, use the following command to install it:

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go get go.opentelemetry.io/otel/sdk@v1.11.2

Set OpenTelemetry SDK TracerProvider and TextMapPropagator globally before capturing any spans to enrich distributed traces with OpenTelemetry spans:

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otel.SetTracerProvider(sdktrace.NewTracerProvider())
otel.SetTextMapPropagator(propagation.TraceContext{})

You will be able to see your traces in the Dynatrace web UI as soon as you redeploy your app.

• Install the following dependencies:

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go get go.opentelemetry.io/otel@v1.11.2
go get go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp@v1.11.2
go get go.opentelemetry.io/otel/sdk@v1.11.2

• Add the following imports to your code and create a function to initialize and configure the Tracer Provider:

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import (
  "context"

  "go.opentelemetry.io/otel"
  "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/v1.12.0"

  "log"
)

func InitTracerProvider() *sdktrace.TracerProvider {
  ctx := context.Background()

  res, err := resource.New(ctx,
    resource.WithAttributes(
      semconv.ServiceNameKey.String("go-quickstart"),
      semconv.ServiceVersionKey.String("1.0.1"),
    ),
  )
  if err != nil {
    log.Fatalf("Failed to create resource: %v", err)
  }

  exporter, err := otlptracehttp.New(
    ctx,
    otlptracehttp.WithEndpoint("<URL>"), //TODO Replace <URL> to your SaaS/Managed-URL as mentioned in the next step
    otlptracehttp.WithURLPath("<URL_PATH>"),//TODO Replace <URL_PATH> to your SaaS/Managed-URL-PATH as mentioned in the next step
    otlptracehttp.WithHeaders(map[string]string{"Authorization": "Api-Token <TOKEN>"}), //TODO Replace <TOKEN> with your API Token as mentioned in the next step
  )
  if err != nil {
    log.Fatalf("Failed to create OTLP exporter: %v", err)
  }

  tp := sdktrace.NewTracerProvider(
    sdktrace.WithResource(res),
    sdktrace.WithSampler(sdktrace.AlwaysSample()),
    sdktrace.WithBatcher(exporter),
  )
  otel.SetTracerProvider(tp)
  otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}))
  return tp
}

• In your main method, make sure to call the newly created function:

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func main() {
  tp := InitTracerProvider()
  defer func() {
    if err := tp.Shutdown(context.Background()); err != nil {
      log.Printf("Error shutting down tracer provider: %v", err)
    }
  }()

  //Your code goes here
}

Lastly, you need to define the correct endpoint and token, to make sure your data arrives where it should be.

• To set the endpoint

  1. Use your Environment ID to set the endpoint to which your app will send traces as follows:
     • Remove the https:// from the URL:
     • Dynatrace SaaS {your-environment-id}.live.dynatrace.com
     • Dynatrace Managed {your-domain}
     • Dynatrace ActiveGate {your-activegate-endpoint}
       • You may need to include the port to your ActiveGate endpoint. For example:
         • {your-activegate-endpoint}:9999
       • If you are running a containerized ActiveGate, you need to use the FQDN of it. For example:
         • {your-activegate-service-name}.dynatrace.svc.cluster.local
  2. Replace <URL> in the code snippet above with your endpoint.

• To set the URL path

  1. Use the following pattern:
  • Dynatrace SaaS /api/v2/otlp/v1/traces
  • Dynatrace Managed and Dynatrace ActiveGate /e/{your-environment-id}/api/v2/otlp/v1/traces
  2. Replace <URL_PATH> in the code snippet above with your URL path.

• To create an authentication token

  1. In the Dynatrace menu, go to Access tokens and select Generate new token.
  2. Provide a Token name.
  3. In the Search scopes box, search for Ingest OpenTelemetry traces and select the checkbox.
  4. Select Generate token.
  5. Select Copy to copy the token to your clipboard.
  6. Save the token in a safe place; you can't display it again.
  7. Replace <TOKEN> in the code snippet above with your token.