algnhsa

README

algnhsa

algnhsa is an AWS Lambda Go net/http server adapter.

algnhsa enables running Go web applications on AWS Lambda and API Gateway or ALB without changing the existing HTTP handlers:

package main

import (
    "fmt"
    "net/http"
    "strconv"

    "github.com/akrylysov/algnhsa"
)

func indexHandler(w http.ResponseWriter, r *http.Request) {
    w.Write([]byte("index"))
}

func addHandler(w http.ResponseWriter, r *http.Request) {
    f, _ := strconv.Atoi(r.FormValue("first"))
    s, _ := strconv.Atoi(r.FormValue("second"))
    w.Header().Set("X-Hi", "foo")
    fmt.Fprintf(w, "%d", f+s)
}

func contextHandler(w http.ResponseWriter, r *http.Request) {
    proxyReq, ok := algnhsa.ProxyRequestFromContext(r.Context())
    if ok {
        fmt.Fprint(w, proxyReq.RequestContext.AccountID)
    }
}

func main() {
    http.HandleFunc("/", indexHandler)
    http.HandleFunc("/add", addHandler)
    http.HandleFunc("/context", contextHandler)
    algnhsa.ListenAndServe(http.DefaultServeMux, nil)
}

Plug in a third-party HTTP router

package main

import (
    "net/http"

    "github.com/akrylysov/algnhsa"
    "github.com/go-chi/chi"
)

func main() {
    r := chi.NewRouter()
    r.Get("/", func(w http.ResponseWriter, r *http.Request) {
        w.Write([]byte("index"))
    })
    algnhsa.ListenAndServe(r, nil)
}

Setting up API Gateway

1. Create a new REST API.

2. In the "Resources" section create a new ANY method to handle requests to / (check "Use Lambda Proxy Integration").

   

3. Add a catch-all {proxy+} resource to handle requests to every other path (check "Configure as proxy resource").

   

Setting up ALB

1. Create a new ALB and point it to your Lambda function.

2. In the target group settings enable "Multi value headers".

Documentation

Overview

Example

package main

import (
	"fmt"
	"net/http"
	"strconv"

	"github.com/akrylysov/algnhsa"
)

func indexHandler(w http.ResponseWriter, r *http.Request) {
	w.Write([]byte("index"))
}

func addHandler(w http.ResponseWriter, r *http.Request) {
	f, _ := strconv.Atoi(r.FormValue("first"))
	s, _ := strconv.Atoi(r.FormValue("second"))
	w.Header().Set("X-Hi", "foo")
	fmt.Fprintf(w, "%d", f+s)
}

func contextHandler(w http.ResponseWriter, r *http.Request) {
	proxyReq, ok := algnhsa.ProxyRequestFromContext(r.Context())
	if ok {
		fmt.Fprint(w, proxyReq.RequestContext.AccountID)
	}
}

func main() {
	http.HandleFunc("/", indexHandler)
	http.HandleFunc("/add", addHandler)
	http.HandleFunc("/context", contextHandler)
	algnhsa.ListenAndServe(http.DefaultServeMux, nil)
}

Index

• func ListenAndServe(handler http.Handler, opts *Options)
• func ProxyRequestFromContext(ctx context.Context) (events.APIGatewayProxyRequest, bool)
• func TargetGroupRequestFromContext(ctx context.Context) (events.ALBTargetGroupRequest, bool)
• type Options
• type RequestType

Examples

• Package

Functions

func ListenAndServe

func ListenAndServe(handler http.Handler, opts *Options)

ListenAndServe starts the AWS Lambda runtime (aws-lambda-go lambda.Start) with a given handler.

func ProxyRequestFromContext

func ProxyRequestFromContext(ctx context.Context) (events.APIGatewayProxyRequest, bool)

ProxyRequestFromContext extracts the APIGatewayProxyRequest event from ctx.

func TargetGroupRequestFromContext

func TargetGroupRequestFromContext(ctx context.Context) (events.ALBTargetGroupRequest, bool)

TargetGroupRequestFromContext extracts the ALBTargetGroupRequest event from ctx.

Types

type Options

type Options struct {
	// RequestType sets the expected request type.
	// By default algnhsa deduces the request type from the lambda function payload.
	RequestType RequestType

	// BinaryContentTypes sets content types that should be treated as binary types.
	// The "*/* value makes algnhsa treat any content type as binary.
	BinaryContentTypes []string

	// Use API Gateway PathParameters["proxy"] when constructing the request url.
	// Strips the base path mapping when using a custom domain with API Gateway.
	UseProxyPath bool
	// contains filtered or unexported fields
}

Options holds the optional parameters.

type RequestType

type RequestType int

const (
	RequestTypeAuto RequestType = iota
	RequestTypeAPIGateway
	RequestTypeALB
)