README.md

OpenTelemetry AWS Lambda Instrumentation for Golang

This module provides instrumentation for AWS Lambda.

Installation

go get -u go.opentelemetry.io/contrib/instrumentation/github.com/aws/aws-lambda-go/otellambda

example

See ./example

Usage

Create a sample Lambda Go application such as below.

package main

import (
	"context"
	"fmt"
	"github.com/aws/aws-lambda-go/lambda"
)

type MyEvent struct {
	Name string `json:"name"`
}

func HandleRequest(ctx context.Context, name MyEvent) (string, error) {
	return fmt.Sprintf("Hello %s!", name.Name ), nil
}

func main() {
	lambda.Start(HandleRequest)
}

Now use the provided wrapper to instrument your basic Lambda function:

// Add import
import "go.opentelemetry.io/contrib/instrumentation/github.com/aws/aws-lambda-go/otellambda"

// wrap lambda handler function
func main() {
    lambda.Start(otellambda.InstrumentHandler(HandleRequest))
}

AWS Lambda Instrumentation Options

Options	Input Type	Description	Default
WithTracerProvider	trace.TracerProvider	Provide a custom TracerProvider for creating spans. Consider using the AWS Lambda Resource Detector with your tracer provider to improve tracing information.	otel.GetTracerProvider()
WithFlusher	otellambda.Flusher	This instrumentation will call the ForceFlush method of its Flusher at the end of each invocation. Should you be using asynchronous logic (such as sddktrace's BatchSpanProcessor) it is very import for spans to be ForceFlush'ed before Lambda freezes to avoid data delays.	Flusher with noop ForceFlush
WithEventToCarrier	func(eventJSON []byte) propagation.TextMapCarrier{}	Function for providing custom logic to support retrieving trace header from different event types that are handled by AWS Lambda (e.g., SQS, CloudWatch, Kinesis, API Gateway) and returning them in a propagation.TextMapCarrier which a Propagator can use to extract the trace header into the context.	Function which returns an empty TextMapCarrier - new spans will be part of a new Trace and have no parent past Lambda instrumentation span
WithPropagator	propagation.Propagator	The Propagator the instrumentation will use to extract trace information into the context.	otel.GetTextMapPropagator()

Usage With Options Example

var someHeaderKey = "Key" // used by propagator and EventToCarrier function to identify trace header

type mockHTTPRequest struct {
    Headers map[string][]string
    Body string
}

func mockEventToCarrier(eventJSON []byte) propagation.TextMapCarrier{
    var request mockHTTPRequest
    _ = json.unmarshal(eventJSON, &request)
    return propogation.HeaderCarrier{someHeaderKey: []string{request.Headers[someHeaderKey]}}
}

type mockPropagator struct{}
// Extract - read from `someHeaderKey`
// Inject
// Fields

func HandleRequest(ctx context.Context, request mockHTTPRequest) error {
    return fmt.Sprintf("Hello %s!", request.Body ), nil
}

func main() {
    exp, _ := stdouttrace.New()

    tp := sdktrace.NewTracerProvider(
    sdktrace.WithBatcher(exp))

    lambda.Start(otellambda.InstrumentHandler(HandleRequest,
                                                otellambda.WithTracerProvider(tp),
                                                otellambda.WithFlusher(tp),
                                                otellambda.WithEventToCarrier(mockEventToCarrier),
                                                otellambda.WithPropagator(mockPropagator{})))
}

Useful links

• For more information on OpenTelemetry, visit: https://opentelemetry.io/
• For more about OpenTelemetry Go: https://github.com/open-telemetry/opentelemetry-go
• For help or feedback on this project, join us in GitHub Discussions

License

Apache 2.0 - See LICENSE for more information.