cmd: CMD option for port number of gogs web to prevent first time run conflict

- routers: use new binding convention to simplify code
- templates: able to set HTTP port number in install page

cmd/web.go

@@ -53,7 +53,9 @@ var CmdWeb = cli.Command{
 	Description: `Gogs web server is the only thing you need to run,
 and it takes care of all the other things for you`,
 	Action: runWeb,
-	Flags:  []cli.Flag{},
+	Flags: []cli.Flag{
+		cli.StringFlag{"port, p", "3000", "Temporary port number to prevent conflict", ""},
+	},
 }
 
 type VerChecker struct {
@@ -162,7 +164,7 @@ func newMacaron() *macaron.Macaron {
 	return m
 }
 
-func runWeb(*cli.Context) {
+func runWeb(ctx *cli.Context) {
 	routers.GlobalInit()
 	checkVersion()
 
@@ -179,9 +181,9 @@ func runWeb(*cli.Context) {
 	// Routers.
 	m.Get("/", ignSignIn, routers.Home)
 	m.Get("/explore", ignSignIn, routers.Explore)
-	// FIXME: when i'm binding form here???
-	m.Get("/install", bindIgnErr(auth.InstallForm{}), routers.Install)
-	m.Post("/install", bindIgnErr(auth.InstallForm{}), routers.InstallPost)
+	m.Combo("/install", routers.InstallInit).
+		Get(routers.Install).
+		Post(bindIgnErr(auth.InstallForm{}), routers.InstallPost)
 	m.Group("", func() {
 		m.Get("/pulls", user.Pulls)
 		m.Get("/issues", user.Issues)
@@ -460,6 +462,12 @@ func runWeb(*cli.Context) {
 	// Not found handler.
 	m.NotFound(routers.NotFound)
 
+	// Flag for port number in case first time run conflict.
+	if ctx.IsSet("port") {
+		setting.AppUrl = strings.Replace(setting.AppUrl, setting.HttpPort, ctx.String("port"), 1)
+		setting.HttpPort = ctx.String("port")
+	}
+
 	var err error
 	listenAddr := fmt.Sprintf("%s:%s", setting.HttpAddr, setting.HttpPort)
 	log.Info("Listen: %v://%s%s", setting.Protocol, listenAddr, setting.AppSubUrl)