OpenTelemetry AWS Lambda Instrumentation for Golang

This module provides instrumentation for AWS Lambda.

Installation

go get -u github.com/helios/opentelemetry-go-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 "github.com/helios/opentelemetry-go-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.

# README