Changed autodetection of SiteURL (#3764)

* Changed autoconfiguration of SiteURL to be done on every request

* Added SiteURL to system console

api/context.go

@@ -39,6 +39,7 @@ type Context struct {
 	Err          *model.AppError
 	teamURLValid bool
 	teamURL      string
+	siteURL      string
 	T            goi18n.TranslateFunc
 	Locale       string
 	TeamId       string
@@ -141,10 +142,11 @@ func (h handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		isTokenFromQueryString = true
 	}
 
-	// if the site url in the config isn't specified, infer if from this request and write it back to the config
-	if *utils.Cfg.ServiceSettings.SiteURL == "" {
-		*utils.Cfg.ServiceSettings.SiteURL = GetProtocol(r) + "://" + r.Host
-		utils.RegenerateClientConfig()
+	if *utils.Cfg.ServiceSettings.SiteURL != "" {
+		c.SetSiteURL(*utils.Cfg.ServiceSettings.SiteURL)
+	} else {
+		protocol := GetProtocol(r)
+		c.SetSiteURL(protocol + "://" + r.Host)
 	}
 
 	w.Header().Set(model.HEADER_REQUEST_ID, c.RequestId)
@@ -439,6 +441,10 @@ func (c *Context) SetTeamURLFromSession() {
 	}
 }
 
+func (c *Context) SetSiteURL(url string) {
+	c.siteURL = url
+}
+
 func (c *Context) GetTeamURLFromTeam(team *model.Team) string {
 	return c.GetSiteURL() + "/" + team.Name
 }
@@ -454,7 +460,7 @@ func (c *Context) GetTeamURL() string {
 }
 
 func (c *Context) GetSiteURL() string {
-	return *utils.Cfg.ServiceSettings.SiteURL
+	return c.siteURL
 }
 
 func IsApiCall(r *http.Request) bool {