[Feature Request] Add a sample with opentelemetry tracing about samples-go

[cretz]

We usually do not recommend doing this because it can be non-deterministic assuming a worker is setup with OTel. Having said that, you can likely set the SpanContextKey option in the opentelemetry.TracerOptions and check that key in the workflow context. (also, feel free to use forums or Slack for general questions if that's easier)

[cretz]

Here's a sample I wrote for a user:

package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"github.com/google/uuid"
	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/exporters/stdout/stdouttrace"
	"go.opentelemetry.io/otel/sdk/resource"
	sdktrace "go.opentelemetry.io/otel/sdk/trace"
	semconv "go.opentelemetry.io/otel/semconv/v1.17.0"
	"go.temporal.io/sdk/client"
	"go.temporal.io/sdk/contrib/opentelemetry"
	"go.temporal.io/sdk/interceptor"
	"go.temporal.io/sdk/testsuite"
	"go.temporal.io/sdk/worker"
	"go.temporal.io/sdk/workflow"
)

func main() {
	if err := run(); err != nil {
		log.Fatal(err)
	}
}

func run() error {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	// Initialize tracer
	exp, err := stdouttrace.New(stdouttrace.WithPrettyPrint())
	if err != nil {
		return fmt.Errorf("failed to initialize stdouttrace exporter: %w", err)
	}
	prov := sdktrace.NewTracerProvider(
		sdktrace.WithBatcher(exp),
		sdktrace.WithResource(resource.NewWithAttributes(
			semconv.SchemaURL,
			semconv.ServiceName("temporal-example"),
			semconv.ServiceVersion("0.0.1"),
		)),
	)
	defer prov.Shutdown(ctx)
	otel.SetTracerProvider(prov)

	// Start dev server
	tracingInterceptor, err := opentelemetry.NewTracingInterceptor(opentelemetry.TracerOptions{})
	if err != nil {
		return err
	}
	srv, err := testsuite.StartDevServer(ctx, testsuite.DevServerOptions{
		ClientOptions: &client.Options{
			Interceptors: []interceptor.ClientInterceptor{tracingInterceptor},
		},
		LogLevel: "error",
	})
	if err != nil {
		return err
	}
	defer srv.Stop()

	// Start worker
	log.Print("Running worker")
	taskQueue := uuid.NewString()
	w := worker.New(srv.Client(), taskQueue, worker.Options{})
	w.RegisterWorkflow(MyWorkflow)
	w.RegisterActivity(MyActivity)
	if err := w.Start(); err != nil {
		return err
	}
	defer w.Stop()

	// Run workflow
	log.Print("Running workflow")
	run, err := srv.Client().ExecuteWorkflow(
		ctx,
		client.StartWorkflowOptions{TaskQueue: taskQueue},
		MyWorkflow,
	)
	if err != nil {
		return err
	} else if err = run.Get(ctx, nil); err != nil {
		return err
	}
	log.Print("Workflow complete")
	return nil
}

func MyWorkflow(ctx workflow.Context) error {
	ctx = workflow.WithActivityOptions(ctx, workflow.ActivityOptions{
		StartToCloseTimeout: 10 * time.Second,
	})
	return workflow.ExecuteActivity(ctx, MyActivity).Get(ctx, nil)
}

func MyActivity(context.Context) error {
	log.Print("Executing activity")
	return nil
}

[Hades32]

for reference, this is what we're currently doing and it seems to work fine

import (
	"go.temporal.io/sdk/contrib/opentelemetry"
	"go.temporal.io/sdk/interceptor"
	"go.temporal.io/sdk/client"
)
func init() {
	tracingInterceptor, err := opentelemetry.NewTracingInterceptor(opentelemetry.TracerOptions{})
	options := client.Options{
		Interceptors:       []interceptor.ClientInterceptor{tracingInterceptor},
	}
	c, err := client.Dial(options)

[jjkoh95]

Hi, the above code works
is there a way to pull trace from workflow context?

[jjkoh95]

Thanks, I need it to better correlate logs from workflow for other log aggregator instead of temporal. (let me know if there's a better way to do this)
I managed to get it work by changing a custom SpanContextKey.

[emanuelef]

@Hades32 I guess this is what you do on the client side, did you have to add the Otel stanza in the Temporal deploy as documented here ?
https://github.com/temporalio/temporal/blob/master/develop/docs/tracing.md#configuring

[Hades32]

@emanuelef no, I didn't change the Temporal deployment. I guess that would only be needed if you want to get detailed information on what's going on inside Temporal. I only cared about knowing which signals were sent, activities and workflows started, etc, and we get all that

[emanuelef]

Thanks @Hades32, I'll try to do the same
Where did you add the collector endpoint ? just add OTEL_EXPORTER_OTLP_ENDPOINT ?
And didn't you need to instrument the custom Temporal worker with your workflows and activities ?

[Quinn-With-Two-Ns]

Closed by #296