AWS Lambda+Goで、fujiwara/ridgeからapex/gatewayへ移行する

--- main_old.go	2018-04-07 00:06:44.000000000 +0900
+++ main.go	2018-04-07 00:09:00.000000000 +0900
@@ -4,7 +4,7 @@
 	"fmt"
 	"net/http"

-	"github.com/fujiwara/ridge"
+	"github.com/apex/gateway"
 )

 var mux = http.NewServeMux()
@@ -15,7 +15,7 @@
 }

 func main() {
-	ridge.Run(":8080", "/api", mux)
+	gateway.ListenAndServe(":8080", mux)
 }

// ListenAndServe is a drop-in replacement for
// http.ListenAndServe for use within AWS Lambda.
//
// ListenAndServe always returns a non-nil error.
func ListenAndServe(addr string, h http.Handler) error {
	if h == nil {
		h = http.DefaultServeMux
	}

	lambda.Start(func(ctx context.Context, e events.APIGatewayProxyRequest) (events.APIGatewayProxyResponse, error) {
		r, err := NewRequest(ctx, e)
		if err != nil {
			return events.APIGatewayProxyResponse{}, err
		}

		w := NewResponse()
		h.ServeHTTP(w, r)
		return w.End(), nil
	})

	return nil
}

// ResponseWriter implements the http.ResponseWriter interface
// in order to support the API Gateway Lambda HTTP "protocol".
type ResponseWriter struct {
	out           events.APIGatewayProxyResponse
	buf           bytes.Buffer
	header        http.Header
	wroteHeader   bool
	closeNotifyCh chan bool
}

// Write implementation.
func (w *ResponseWriter) Write(b []byte) (int, error) {
	if !w.wroteHeader {
		w.WriteHeader(http.StatusOK)
	}

	return w.buf.Write(b)
}

// End the request.
func (w *ResponseWriter) End() events.APIGatewayProxyResponse {
	w.out.IsBase64Encoded = isBinary(w.header)

	if w.out.IsBase64Encoded {
		w.out.Body = base64.StdEncoding.EncodeToString(w.buf.Bytes())
	} else {
		w.out.Body = w.buf.String()
	}

	// notify end
	w.closeNotifyCh <- true

	return w.out
}