Add GetRequestSourceIP function

ip_utils/ip_utils.go

@@ -2,7 +2,9 @@ package ip_utils
 
 import (
 	"fmt"
+	"github.com/aws/aws-lambda-go/events"
 	"gitlab.bob.co.za/bob-public-utils/bobgroup-go-utils/errors"
+	"gitlab.bob.co.za/bob-public-utils/bobgroup-go-utils/handler_utils"
 	"net"
 	"os"
 	"strings"
@@ -163,4 +165,27 @@ func ValidateIPAddress(ipAddress string) (cleanedIPAddress string, err error) {
 	return ipAddress, nil
 }
 
+func GetRequestSourceIP(proxyRequest *events.APIGatewayProxyRequest, websocketReqeuest *events.APIGatewayWebsocketProxyRequest) string {
+	var requestSourceIP string
+	if proxyRequest != nil {
+		requestSourceIP = proxyRequest.RequestContext.Identity.SourceIP
+		// Cloudflare uses this header to pass the real IP
+		forwardedForHeader := handler_utils.FindHeaderValue(proxyRequest.Headers, "x-forwarded-for")
+		if forwardedForHeader != "" &&
+			VerifyCloudflareSourceIP(requestSourceIP) {
+			forwardedForHeaderIPs := strings.Split(forwardedForHeader, ",")
+
+			if len(forwardedForHeaderIPs) > 0 {
+				// Use the first IP as the source IP
+				headerSourceIP := strings.TrimSpace(forwardedForHeaderIPs[len(forwardedForHeaderIPs)-1])
+				return headerSourceIP
+			}
+		}
+	} else if websocketReqeuest != nil {
+		requestSourceIP = websocketReqeuest.RequestContext.Identity.SourceIP
+	}
+
+	return requestSourceIP
+}
+
 // endregion Helpers