Add an option to allow redirect of http port 80 to https. (#1928)

* Add an option to allow redirect of http port 80 to https.

This is an "opt in" option (default is to not redirect).  It will only redirect
if protocol is https and the new REDIRECT_PORT_80 option is set to true.

The Port to redirect in previous commit was hardcoded to 80, now it can be
specified in the app.ini, defaulting to 80.  The boolean option to turn
redirection on has been changed to REDIRECT_OTHER_PORT to be logically
consistent with the new port option.

Signed-off-by: Mike Fellows <mike.fellows@shaw.ca>

cmd/web.go

 	},
 }
 
+func runHTTPRedirector() {
+	source := fmt.Sprintf("%s:%s", setting.HTTPAddr, setting.PortToRedirect)
+	dest := strings.TrimSuffix(setting.AppURL, "/")
+	log.Info("Redirecting: %s to %s", source, dest)
+
+	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		target := dest + r.URL.Path
+		if len(r.URL.RawQuery) > 0 {
+			target += "?" + r.URL.RawQuery
+		}
+		http.Redirect(w, r, target, http.StatusTemporaryRedirect)
+	})
+
+	var err = runHTTP(source, context2.ClearHandler(handler))
+
+	if err != nil {
+		log.Fatal(4, "Failed to start port redirection: %v", err)
+	}
+}
+
 func runWeb(ctx *cli.Context) error {
 	if ctx.IsSet("config") {
 		setting.CustomConf = ctx.String("config")
 	case setting.HTTP:
 		err = runHTTP(listenAddr, context2.ClearHandler(m))
 	case setting.HTTPS:
+		if setting.RedirectOtherPort {
+			go runHTTPRedirector()
+		}
 		err = runHTTPS(listenAddr, setting.CertFile, setting.KeyFile, context2.ClearHandler(m))
 	case setting.FCGI:
 		listener, err := net.Listen("tcp", listenAddr)

custom/conf/app.ini.sample

 ; Listen address. Either a IPv4/IPv6 address or the path to a unix socket.
 HTTP_ADDR = 0.0.0.0
 HTTP_PORT = 3000
+; If REDIRECT_OTHER_PORT is true, and PROTOCOL is set to https an http server
+; will be started on PORT_TO_REDIRECT and redirect request to the main
+; ROOT_URL.  Defaults are false for REDIRECT_OTHER_PORT and 80 for
+; PORT_TO_REDIRECT.
+REDIRECT_OTHER_PORT = false
+PORT_TO_REDIRECT = 80
 ; Permission for unix socket
 UNIX_SOCKET_PERMISSION = 666
 ; Local (DMZ) URL for Gitea workers (such as SSH update) accessing web service.

modules/setting/setting.go

 	HTTPAddr             string
 	HTTPPort             string
 	LocalURL             string
+	RedirectOtherPort    bool
+	PortToRedirect       string
 	OfflineMode          bool
 	DisableRouterLog     bool
 	CertFile             string
 		defaultLocalURL += ":" + HTTPPort + "/"
 	}
 	LocalURL = sec.Key("LOCAL_ROOT_URL").MustString(defaultLocalURL)
+	RedirectOtherPort = sec.Key("REDIRECT_OTHER_PORT").MustBool(false)
+	PortToRedirect = sec.Key("PORT_TO_REDIRECT").MustString("80")
 	OfflineMode = sec.Key("OFFLINE_MODE").MustBool()
 	DisableRouterLog = sec.Key("DISABLE_ROUTER_LOG").MustBool()
 	StaticRootPath = sec.Key("STATIC_ROOT_PATH").MustString(AppWorkPath)