fix(fiber): Fix fiber returning 500 internal server error

fde5929 caused a regression
in the fiber adapter logic as we previously would try to get the source IP from nil, which
internally would just return an empty string.

Since above commit, the RemoteAddr is not nil anymore, but is lacking the required port
that is needed in order to parse it as a *TCPAddr

This commit makes sure the port section is always added if it does not exist. Furthermore, it
adds a test that prevents this from happening again and we now have logging in place.

Author: marvin-w

fiber/adapter.go

@@ -5,9 +5,12 @@ package fiberadapter
 
 import (
 	"context"
-	"io/ioutil"
+	"fmt"
+	"io"
+	"log"
 	"net"
 	"net/http"
+	"strings"
 
 	"github.com/aws/aws-lambda-go/events"
 	"github.com/gofiber/fiber/v2"
@@ -103,7 +106,7 @@ func (f *FiberLambda) adaptor(w http.ResponseWriter, r *http.Request) {
 	defer fasthttp.ReleaseRequest(req)
 
 	// Convert net/http -> fasthttp request
-	body, err := ioutil.ReadAll(r.Body)
+	body, err := io.ReadAll(r.Body)
 	if err != nil {
 		http.Error(w, utils.StatusMessage(fiber.StatusInternalServerError), fiber.StatusInternalServerError)
 		return
@@ -129,8 +132,16 @@ func (f *FiberLambda) adaptor(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	remoteAddr, err := net.ResolveTCPAddr("tcp", r.RemoteAddr)
+	// We need to make sure the net.ResolveTCPAddr call works as it expects a port
+	addrWithPort := r.RemoteAddr
+	if !strings.Contains(r.RemoteAddr, ":") {
+		addrWithPort = r.RemoteAddr + ":80" // assuming a default port
+	}
+
+	remoteAddr, err := net.ResolveTCPAddr("tcp", addrWithPort)
 	if err != nil {
+		fmt.Printf("could not resolve TCP address for addr %s\n", r.RemoteAddr)
+		log.Println(err)
 		http.Error(w, utils.StatusMessage(fiber.StatusInternalServerError), fiber.StatusInternalServerError)
 		return
 	}

fiber/fiberlambda_test.go

@@ -39,6 +39,39 @@ var _ = Describe("FiberLambda tests", func() {
 		})
 	})
 
+	Context("RemoteAddr handling", func() {
+		It("Properly parses the IP address", func() {
+			app := fiber.New()
+			app.Get("/ping", func(c *fiber.Ctx) error {
+				// make sure the ip address is actually set properly
+				Expect(c.Context().RemoteAddr().String()).To(Equal("8.8.8.8:80"))
+				return c.SendString("pong")
+			})
+
+			adapter := fiberadaptor.New(app)
+
+			req := events.APIGatewayProxyRequest{
+				Path:       "/ping",
+				HTTPMethod: "GET",
+				RequestContext: events.APIGatewayProxyRequestContext{
+					Identity: events.APIGatewayRequestIdentity{
+						SourceIP: "8.8.8.8",
+					},
+				},
+			}
+
+			resp, err := adapter.ProxyWithContext(context.Background(), req)
+
+			Expect(err).To(BeNil())
+			Expect(resp.StatusCode).To(Equal(200))
+
+			resp, err = adapter.Proxy(req)
+
+			Expect(err).To(BeNil())
+			Expect(resp.StatusCode).To(Equal(200))
+		})
+	})
+
 	Context("Request header", func() {
 		It("Check pass canonical header to fiber", func() {
 			app := fiber.New()