aws-lambda-go-http-adapter

README

aws-lambda-go-http-adapter

Simple HTTP adapter for AWS Lambda

Builtin support for these event formats:

• AWS Lambda Function URL (both normal and streaming)
• API Gateway (v1)
• API Gateway (v2)

Builtin support for these HTTP frameworks:

• net/http
• Echo
• Fiber

Usage

Creating the Adapter

net/http

package main

import (
	"github.com/its-felix/aws-lambda-go-http-adapter/adapter/vanilla"
	"net/http"
)

func main() {
	mux := http.NewServeMux()
	mux.HandleFunc("/ping", func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		_, _ = w.Write([]byte("pong"))
	})
	
	adapter := vanilla.NewAdapter(mux)
}

Echo

package main

import (
	"github.com/labstack/echo/v4"
	echoadapter "github.com/its-felix/aws-lambda-go-http-adapter/adapter/echo"
	"net/http"
)

func main() {
	e := echo.New()
	e.Add("GET", "/ping", func(c echo.Context) error {
		return c.String(200, "pong")
	})
	
	adapter := echoadapter.NewAdapter(e)
}

Fiber

package main

import (
	"github.com/gofiber/fiber/v2"
	fiberadapter "github.com/its-felix/aws-lambda-go-http-adapter/adapter/fiber"
	"net/http"
)

func main() {
	app := fiber.New()
	app.Get("/ping", func(ctx *fiber.Ctx) error {
		return ctx.SendString("pong")
	})

	adapter := fiberadapter.NewAdapter(app)
}

Creating the Handler

API Gateway V1

package main

import (
	"github.com/aws/aws-lambda-go/lambda"
	"github.com/its-felix/aws-lambda-go-http-adapter/handler"
)

func main() {
	adapter := [...] // see above
	h := handler.NewAPIGatewayV1Handler(adapter)
	
	lambda.Start(h)
}

API Gateway V2

package main

import (
	"github.com/aws/aws-lambda-go/lambda"
	"github.com/its-felix/aws-lambda-go-http-adapter/handler"
)

func main() {
	adapter := [...] // see above
	h := handler.NewAPIGatewayV2Handler(adapter)
	
	lambda.Start(h)
}

Lambda Function URL (normal)

package main

import (
	"github.com/aws/aws-lambda-go/lambda"
	"github.com/its-felix/aws-lambda-go-http-adapter/handler"
)

func main() {
	adapter := [...] // see above
	h := handler.NewFunctionURLHandler(adapter)
	
	lambda.Start(h)
}

Lambda Function URL (streaming)

package main

import (
	"github.com/aws/aws-lambda-go/lambda"
	"github.com/its-felix/aws-lambda-go-http-adapter/handler"
)

func main() {
	adapter := [...] // see above
	h := handler.NewFunctionURLStreamingHandler(adapter)
	
	lambda.Start(h)
}

Accessing the source event

Fiber

package main

import (
	"github.com/aws/aws-lambda-go/events"
	"github.com/gofiber/fiber/v2"
	fiberadapter "github.com/its-felix/aws-lambda-go-http-adapter/adapter/fiber"
)

func main() {
	app := fiber.New()
	app.Get("/ping", func(ctx *fiber.Ctx) error {
		event := fiberadapter.GetSourceEvent(ctx)
		switch event := event.(type) {
		case events.APIGatewayProxyRequest:
			// do something
		case events.APIGatewayV2HTTPRequest:
			// do something
		case events.LambdaFunctionURLRequest:
			// do something
		}
		
		return ctx.SendString("pong")
	})
}

Others

package main

import (
	"github.com/aws/aws-lambda-go/events"
	"github.com/its-felix/aws-lambda-go-http-adapter/handler"
	"net/http"
)

func main() {
	mux := http.NewServeMux()
	mux.HandleFunc("/ping", func(w http.ResponseWriter, r *http.Request) {
		event := handler.GetSourceEvent(r.Context())
		switch event := event.(type) {
		case events.APIGatewayProxyRequest:
			// do something
		case events.APIGatewayV2HTTPRequest:
			// do something
		case events.LambdaFunctionURLRequest:
			// do something
		}
		
		w.WriteHeader(http.StatusOK)
		_, _ = w.Write([]byte("pong"))
	})
}

Handle panics

To handle panics, first create the handler as described above. You can then wrap the handler to handle panics like so:

package main

import (
	"context"
	"github.com/aws/aws-lambda-go/lambda"
	"github.com/aws/aws-lambda-go/events"
	"github.com/its-felix/aws-lambda-go-http-adapter/handler"
)

func main() {
	adapter := [...] // see above
	h := [...] // see above
	h = handler.WrapWithRecover(h, func(ctx context.Context, event events.APIGatewayV2HTTPRequest, panicValue any) (events.APIGatewayV2HTTPResponse, error) {
		return events.APIGatewayV2HTTPResponse{
			StatusCode:        500,
			Headers:           make(map[string]string),
			Body:              fmt.Sprintf("Unexpected error: %v", panicValue),
		}, nil
	})
	
	lambda.Start(h)
}

Extending for other lambda event formats:

Have a look at the existing event handlers:

• API Gateway V1
• API Gateway V2
• Lambda Function URL

Extending for other frameworks

Have a look at the existing adapters:

• net/http
• Echo
• Fiber

Build Tags

You can opt-in to enable partial build by using the build-tag lambdahttpadapter.partial.

Once this build-tag is present, the following build-tags are available:

• lambdahttpadapter.vanilla (enables the vanilla adapter)
• lambdahttpadapter.echo (enables the echo adapter)
• lambdahttpadapter.fiber (enables the fiber adapter)
• lambdahttpadapter.apigwv1 (enables API Gateway V1 handler)
• lambdahttpadapter.apigwv2 (enables API Gateway V2 handler)
• lambdahttpadapter.functionurl (enables Lambda Function URL handler)

Also note that Lambda Function URL in Streaming-Mode requires the following build-tag to be set:

• lambda.norpc