Merge pull request #7 from Plaenkler/development

Added support for proxy operation

Author: Plaenkler

README.md

@@ -35,7 +35,7 @@ DDNS provides a straightforward way to update dynamic DNS entries without fiddli
 
 ### Deploy with Docker
 
-It is recommended to use [docker-compose](https://docs.docker.com/compose/) as it is very convenient. The following example shows a simple deployment without a proxy.
+It is recommended to use [docker-compose](https://docs.docker.com/compose/) as it is very convenient. The following example shows a simple deployment:
 
 ```yaml
 ---
@@ -59,6 +59,8 @@ networks:
     external: false
 ```
 
+> **Note:** DDNS can also be operated behind a proxy like [Traefik](https://doc.traefik.io/traefik/).
+
 ### Build from source
 
 From the root of the source tree, run:
@@ -67,7 +69,7 @@ From the root of the source tree, run:
 go build -o ddns.exe cmd/main.go
 ```
 
-> Make sure that CGO is operational!
+> **Note:** Make sure that CGO is operational!
 
 ### Configuration
 

pkg/router/router.go

@@ -52,7 +52,17 @@ func (manager *Manager) Start() {
 			ReadHeaderTimeout: 3 * time.Second,
 			WriteTimeout:      3 * time.Second,
 			IdleTimeout:       120 * time.Second,
-			Handler:           manager.Router,
+			Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				// Read X-Forwarded-For-Header for proxying
+				remoteIP := r.Header.Get("X-Forwarded-For")
+				remotePort := r.Header.Get("X-Forwarded-Port")
+				if remotePort == "" {
+					remotePort = "80"
+				}
+				r.URL.Scheme = "http"
+				r.URL.Host = fmt.Sprintf("%s:%s", remoteIP, remotePort)
+				manager.Router.ServeHTTP(w, r)
+			}),
 		}
 		err = server.ListenAndServe()
 		if err != nil {