Add external-ip function by Alex Ellis

Original source from:

https://github.com/openfaas/cloud-functions

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

external-ip/handler.go

@@ -0,0 +1,31 @@
+// Copyright (c) 2023 Alex Ellis, OpenFaaS Ltd
+// Licensed under the MIT license, see LICENSE.md file.
+
+package function
+
+import (
+	"io"
+	"net/http"
+)
+
+func Handle(w http.ResponseWriter, r *http.Request) {
+
+	if r.Body != nil {
+		defer r.Body.Close()
+	}
+
+	res, err := http.Get("https://api.ipify.org")
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	for k, v := range res.Header {
+		w.Header().Set(k, v[0])
+	}
+
+	if res.Body != nil {
+		defer res.Body.Close()
+		io.Copy(w, res.Body)
+	}
+}

stack.yml

@@ -91,6 +91,11 @@ functions:
     handler: ./certinfo
     image: ${SERVER:-ghcr.io}/${OWNER:-openfaas}/certinfo-fn:${TAG:-latest}
 
+  external-ip:
+    lang: golang-middleware
+    handler: ./external-ip
+    image: ${SERVER:-ghcr.io}/${OWNER:-openfaas}/external-ip-fn:${TAG:-latest}
+
 configuration:
   templates:
     - name: golang-middleware