Sending traces from Go applications via OpenTelemetry

• Overview
• Local host
• Docker
• Kubernetes

Deploy this integration to enable instrumentation of your Go application using OpenTelemetry.

Architecture overview

This integration includes:

• Installing the OpenTelemetry Go instrumentation packages on your application host
• Installing the OpenTelemetry collector with Layerlog exporter
• Running your Go application in conjunction with the OpenTelemetry instrumentation

On deployment, the Go instrumentation automatically captures spans from your application and forwards them to the collector, which exports the data to your Layerlog account.

Setup instrumentation for your locally hosted Go application and send traces to Layerlog

Before you begin, you’ll need:

• A Go application without instrumentation
• An active account with Layerlog
• Port 55681 available on your host system
• A name defined for your tracing service

Download the general instrumentation packages

These packages are required to enable instrumentation for your code regardless of the type of application that you need to instrument.

To download these packages, run the following command from the application directory:

go get -u go.opentelemetry.io/otel
go get -u go.opentelemetry.io/otel/exporters/otlp
go get -u go.opentelemetry.io/otel
go get -u go.opentelemetry.io/otel/attribute
go get -u go.opentelemetry.io/otel/baggage
go get -u go.opentelemetry.io/otel/propagation
go get -u go.opentelemetry.io/otel/sdk/resource
go get -u go.opentelemetry.io/otel/sdk/trace
go get -u go.opentelemetry.io/otel/semconv/v1.4.0
go get -u go.opentelemetry.io/otel/trace
go get -u go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp

We recommend sending OTLP traces using HTTP. This is why we import the otlptracehttp package.

Download the application specific instrumentation packages

Depending on the type of your application, you need to download instrumentation packages specific to your application. For example, if your application is a HTTP server, you will need the opentelemetry.io/contrib/instrumentation/net/http/otelhttp package. The full list of all available packages can be found in the OpenTelemetry contrib directory.

The example below is given for a HTTP server application:

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

Add the instrumentation to the import function

Add all the packages downloaded in the previous steps to the import function of your application.

The example below is given for a HTTP server application:

import (
	"context"
	"io"
	"log"
	"net/http"

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

	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/baggage"
	"go.opentelemetry.io/otel/propagation"
	"go.opentelemetry.io/otel/sdk/resource"
	sdktrace "go.opentelemetry.io/otel/sdk/trace"
	semconv "go.opentelemetry.io/otel/semconv/v1.4.0"
	"go.opentelemetry.io/otel/trace"
	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp"
)

Add the initProvider function

Add the initProvider function to the application code as follows:

func initProvider() func() {
	ctx := context.Background()

	res, err := resource.New(ctx,
		resource.WithAttributes(
			semconv.ServiceNameKey.String("test-service"),
		),
	)
	handleErr(err, "failed to create resource")

	traceExporter, err := otlptracehttp.New(ctx,
		otlptracehttp.WithInsecure(),
		otlptracehttp.WithEndpoint("localhost:55681"),
	)
	handleErr(err, "failed to create trace exporter")

	bsp := sdktrace.NewBatchSpanProcessor(traceExporter)
	tracerProvider := sdktrace.NewTracerProvider(
		sdktrace.WithSampler(sdktrace.AlwaysSample()),
		sdktrace.WithResource(res),
		sdktrace.WithSpanProcessor(bsp),
	)
	otel.SetTracerProvider(tracerProvider)
	otel.SetTextMapPropagator(propagation.TraceContext{})
	return func() {
		handleErr(tracerProvider.Shutdown(ctx), "failed to shutdown TracerProvider")
	}
}

Instrument the code in the main function

In the main function of your application, add the following code:

	shutdown := initProvider()
	defer shutdown()

After this, you need to declare the instrumentation according to your application. The example below is given for a HTTP server application. The HTTP handler instructs the tracer to create spans on each request.

uk := attribute.Key("username")

	helloHandler := func(w http.ResponseWriter, req *http.Request) {
		ctx := req.Context()
		span := trace.SpanFromContext(ctx)
		bag := baggage.FromContext(ctx)
		span.AddEvent("handling this...", trace.WithAttributes(uk.String(bag.Member("username").Value())))

		_, _ = io.WriteString(w, "Hello, world!\n")
	}

	otelHandler := otelhttp.NewHandler(http.HandlerFunc(helloHandler), "Hello")

	http.Handle("/hello", otelHandler)
	err := http.ListenAndServe(":7777", nil)
	if err != nil {
		panic(err)
	}
}
func handleErr(err error, message string) {
	if err != nil {
		log.Fatalf("%s: %v", message, err)
	}

Download and configure OpenTelemetry collector

Create a dedicated directory on the host of your Go application and download the OpenTelemetry collector that is relevant to the operating system of your host.

After downloading the collector, create a configuration file config.yaml with the following parameters:

receivers:
  jaeger:
    protocols:
      thrift_compact:
        endpoint: "0.0.0.0:6831"
      thrift_binary:
        endpoint: "0.0.0.0:6832"
      grpc:
        endpoint: "0.0.0.0:14250"
      thrift_http:
        endpoint: "0.0.0.0:14268"
  opencensus:
    endpoint: "0.0.0.0:55678"
  otlp:
    protocols:
      grpc:
        endpoint: "0.0.0.0:4317"
      http:
        endpoint: "0.0.0.0:4318"
  zipkin:
    endpoint: "0.0.0.0:9411"


exporters:
  logzio:
    account_token: "<<TRACING-SHIPPING-TOKEN>>"
    #region: "<<LOGZIO_ACCOUNT_REGION_CODE>>" - (Optional): Your layerlog.com account region code. Defaults to "us". Required only if your layerlog.com region is different than US East. https://docs.layerlog.com/user-guide/accounts/account-region.html#available-regions

  logging:

processors:
  batch:

extensions:
  pprof:
    endpoint: :1777
  zpages:
    endpoint: :55679
  health_check:

service:
  extensions: [health_check, pprof, zpages]
  pipelines:
    traces:
      receivers: [opencensus, jaeger, zipkin, otlp]
      processors: [batch]
      exporters: [logging, logzio]

Replace <<TRACING-SHIPPING-TOKEN>> with the token of the account you want to ship to.

If your account is hosted in any region other than us, replace LOGZIO_ACCOUNT_REGION_CODE> with the applicable region code.

Start the collector

Run the following command from the directory of your application file:

<path/to>/otelcontribcol_<VERSION-NAME> --config ./config.yaml

• Replace <path/to> with the path to the directory where you downloaded the collector.
• Replace <VERSION-NAME> with the version name of the collector applicable to your system, e.g. otelcontribcol_darwin_amd64.

Run the application

Run the application to generate traces:

go run <YOUR-APPLICATION-FILE-NAME>.go

Check Layerlog for your traces

Give your traces some time to get from your system to ours, and then open Tracing.

Setup instrumentation for your Go application using Docker and send traces to Layerlog

This integration enables you to instrument your Go application and run a containerized OpenTelemetry collector to send your traces to Layerlog. If your application also runs in a Docker container, make sure that both the application and collector containers are on the same network.

Before you begin, you’ll need:

• A Go application without instrumentation
• An active account with Layerlog
• Port 4317 available on your host system
• A name defined for your tracing service

Download the general instrumentation packages

These packages are required to enable instrumentation for your code regardless of the type of application that you need to instrument.

To download these packages, run the following command from the application directory:

go get -u go.opentelemetry.io/otel
go get -u go.opentelemetry.io/otel/exporters/otlp
go get -u go.opentelemetry.io/otel
go get -u go.opentelemetry.io/otel/attribute
go get -u go.opentelemetry.io/otel/baggage
go get -u go.opentelemetry.io/otel/propagation
go get -u go.opentelemetry.io/otel/sdk/resource
go get -u go.opentelemetry.io/otel/sdk/trace
go get -u go.opentelemetry.io/otel/semconv/v1.4.0
go get -u go.opentelemetry.io/otel/trace
go get -u go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp

We recommend sending OTLP traces using HTTP. This is why we import the otlptracehttp package.

Download the application specific instrumentation packages

Depending on the type of your application, you need to download instrumentation packages specific to your application. For example, if your application is a HTTP server, you will need the opentelemetry.io/contrib/instrumentation/net/http/otelhttp package. The full list of all available packages can be found in the OpenTelemetry contrib directory.

The example below is given for a HTTP server application:

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

Add the instrumentation to the import function

Add all the packages downloaded in the previous steps to the import function of your application.

The example below is given for a HTTP server application:

import (
	"context"
	"io"
	"log"
	"net/http"

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

	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/baggage"
	"go.opentelemetry.io/otel/propagation"
	"go.opentelemetry.io/otel/sdk/resource"
	sdktrace "go.opentelemetry.io/otel/sdk/trace"
	semconv "go.opentelemetry.io/otel/semconv/v1.4.0"
	"go.opentelemetry.io/otel/trace"
	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp"
)

Add the initProvider function

Add the initProvider function to the application code as follows:

func initProvider() func() {
	ctx := context.Background()

	res, err := resource.New(ctx,
		resource.WithAttributes(
			semconv.ServiceNameKey.String("test-service"),
		),
	)
	handleErr(err, "failed to create resource")

	traceExporter, err := otlptracehttp.New(ctx,
		otlptracehttp.WithInsecure(),
		otlptracehttp.WithEndpoint("localhost:55681"),
	)
	handleErr(err, "failed to create trace exporter")

	bsp := sdktrace.NewBatchSpanProcessor(traceExporter)
	tracerProvider := sdktrace.NewTracerProvider(
		sdktrace.WithSampler(sdktrace.AlwaysSample()),
		sdktrace.WithResource(res),
		sdktrace.WithSpanProcessor(bsp),
	)
	otel.SetTracerProvider(tracerProvider)
	otel.SetTextMapPropagator(propagation.TraceContext{})
	return func() {
		handleErr(tracerProvider.Shutdown(ctx), "failed to shutdown TracerProvider")
	}
}

Instrument the code in the main function

In the main function of your application, add the following code:

	shutdown := initProvider()
	defer shutdown()

After this, you need to declare the instrumentation according to your application. The example below is given for a HTTP server application. The HTTP handler instructs the tracer to create spans on each request.

uk := attribute.Key("username")

	helloHandler := func(w http.ResponseWriter, req *http.Request) {
		ctx := req.Context()
		span := trace.SpanFromContext(ctx)
		bag := baggage.FromContext(ctx)
		span.AddEvent("handling this...", trace.WithAttributes(uk.String(bag.Member("username").Value())))

		_, _ = io.WriteString(w, "Hello, world!\n")
	}

	otelHandler := otelhttp.NewHandler(http.HandlerFunc(helloHandler), "Hello")

	http.Handle("/hello", otelHandler)
	err := http.ListenAndServe(":7777", nil)
	if err != nil {
		panic(err)
	}
}
func handleErr(err error, message string) {
	if err != nil {
		log.Fatalf("%s: %v", message, err)
	}

Pull the Docker image for the OpenTelemetry collector

docker pull logzio/otel-collector-traces

This integration only works with an otel-contrib image. The logzio/otel-collector-traces image is based on otel-contrib.

Run the container

When running on a Linux host, use the --network host flag to publish the collector ports:

docker run \
-e LOGZIO_REGION=<<LOGZIO_ACCOUNT_REGION_CODE>> \
-e LOGZIO_TRACES_TOKEN=<<TRACING-SHIPPING-TOKEN>> \
--network host \
logzio/otel-collector-traces

When running on MacOS or Windows hosts, publish the ports using the -p flag:

docker run \
-e LOGZIO_REGION=<<LOGZIO_ACCOUNT_REGION_CODE>> \
-e LOGZIO_TRACES_TOKEN=<<TRACING-SHIPPING-TOKEN>> \
-p 55678-55680:55678-55680 \
-p 1777:1777 \
-p 9411:9411 \
-p 9943:9943 \
-p 6831:6831 \
-p 6832:6832 \
-p 14250:14250 \
-p 14268:14268 \
-p 4317:4317 \
-p 55681:55681 \
logzio/otel-collector-traces

Replace <<TRACING-SHIPPING-TOKEN>> with the token of the account you want to ship to.

If your account is hosted in any region other than us, replace LOGZIO_ACCOUNT_REGION_CODE> with the applicable region code.

Run the application

Run the application to generate traces:

go run <YOUR-APPLICATION-FILE-NAME>.go

Check Layerlog for your traces

Give your traces some time to get from your system to ours, and then open Tracing.

Overview

You can use a Helm chart to ship Traces to Layerlog via the OpenTelemetry collector. The Helm tool is used to manage packages of pre-configured Kubernetes resources that use charts.

logzio-otel-traces allows you to ship traces from your Kubernetes cluster to Layerlog with the OpenTelemetry collector.

This chart is a fork of the opentelemtry-collector Helm chart. The main repository for Layerlog helm charts are logzio-helm.

Standard configuration

Deploy the Helm chart

Add logzio-helm repo as follows:

helm repo add logzio-helm https://logzio.github.io/logzio-helm
helm repo update

Define the logzio-otel-traces service name

In most cases, the service name will be logzio-otel-traces.default.svc.cluster.local, where default is the namespace where you deployed the helm chart and svc.cluster.name is your cluster domain name.

If you are not sure what your cluster domain name is, you can run the following command to look it up:

kubectl run -it --image=k8s.gcr.io/e2e-test-images/jessie-dnsutils:1.3 --restart=Never shell -- \
sh -c 'nslookup kubernetes.default | grep Name | sed "s/Name:\skubernetes.default//"'

It will deploy a small pod that extracts your cluster domain name from your Kubernetes environment. You can remove this pod after it has returned the cluster domain name.

Run the Helm deployment code

helm install  \
--set config.exporters.logzio.region=<<LOGZIO_ACCOUNT_REGION_CODE>> \
--set config.exporters.logzio.account_token=<<TRACING-SHIPPING-TOKEN>> \
logzio-otel-traces logzio-helm/logzio-otel-traces

Replace <<TRACING-SHIPPING-TOKEN>> with the token of the account you want to ship to.

If your account is hosted in any region other than us, replace LOGZIO_ACCOUNT_REGION_CODE> with the applicable region code. <<LOGZIO_ACCOUNT_REGION_CODE>> - (Optional): Your layerlog.com account region code. Defaults to “us”. Required only if your layerlog.com region is different than US East. https://docs.layerlog.com/user-guide/accounts/account-region.html#available-regions

Check Layerlog for your traces

Give your traces some time to get from your system to ours, then open Layerlog.

Customizing Helm chart parameters

Configure customization options

You can use the following options to update the Helm chart parameters:

• Specify parameters using the --set key=value[,key=value] argument to helm install.

• Edit the values.yaml.

• Overide default values with your own my_values.yaml and apply it in the helm install command.

Example

helm install logzio-otel-traces logzio-helm/logzio-otel-traces -f my_values.yaml 

Uninstalling the Chart

The uninstall command is used to remove all the Kubernetes components associated with the chart and to delete the release.

To uninstall the logzio-otel-traces deployment, use the following command:

helm uninstall logzio-otel-traces