PLT-8086 Fix plugin config watcher for enabling and disabling (#7770)

* Fix plugin config watcher for enabling and disabling

* Make sure HTTP routes are served

* Set content-type explicitly

app/app.go

@@ -93,6 +93,9 @@ func New(options ...Option) *App {
 	app.Srv.Store = app.newStore()
 	app.initJobs()
 
+	app.Srv.Router.HandleFunc("/plugins/{plugin_id:[A-Za-z0-9\\_\\-\\.]+}", app.ServePluginRequest)
+	app.Srv.Router.HandleFunc("/plugins/{plugin_id:[A-Za-z0-9\\_\\-\\.]+}/{anything:.*}", app.ServePluginRequest)
+
 	app.Srv.Router.NotFoundHandler = http.HandlerFunc(app.Handle404)
 
 	app.Srv.WebSocketRouter = &WebSocketRouter{

app/plugins.go

@@ -557,30 +557,33 @@ func (a *App) InitPlugins(pluginPath, webappPath string) {
 
 	utils.RemoveConfigListener(a.PluginConfigListenerId)
 	a.PluginConfigListenerId = utils.AddConfigListener(func(prevCfg, cfg *model.Config) {
-		if !*prevCfg.PluginSettings.Enable && *cfg.PluginSettings.Enable {
-			a.InitPlugins(pluginPath, webappPath)
-		} else if *prevCfg.PluginSettings.Enable && !*cfg.PluginSettings.Enable {
-			a.ShutDownPlugins()
-		} else if *prevCfg.PluginSettings.Enable && *cfg.PluginSettings.Enable {
-			a.ActivatePlugins()
-		}
-
 		if a.PluginEnv == nil {
 			return
 		}
 
+		if *prevCfg.PluginSettings.Enable && *cfg.PluginSettings.Enable {
+			a.ActivatePlugins()
+		}
+
 		for _, err := range a.PluginEnv.Hooks().OnConfigurationChange() {
 			l4g.Error(err.Error())
 		}
 	})
 
-	a.Srv.Router.HandleFunc("/plugins/{plugin_id:[A-Za-z0-9\\_\\-\\.]+}", a.ServePluginRequest)
-	a.Srv.Router.HandleFunc("/plugins/{plugin_id:[A-Za-z0-9\\_\\-\\.]+}/{anything:.*}", a.ServePluginRequest)
-
 	a.ActivatePlugins()
 }
 
 func (a *App) ServePluginRequest(w http.ResponseWriter, r *http.Request) {
+	if a.PluginEnv == nil || !*a.Config().PluginSettings.Enable {
+		err := model.NewAppError("ServePluginRequest", "app.plugin.disabled.app_error", nil, "Enable plugins to serve plugin requests", http.StatusNotImplemented)
+		err.Translate(utils.T)
+		l4g.Error(err.Error())
+		w.WriteHeader(err.StatusCode)
+		w.Header().Set("Content-Type", "application/json")
+		w.Write([]byte(err.ToJson()))
+		return
+	}
+
 	token := ""
 
 	authHeader := r.Header.Get(model.HEADER_AUTH)

cmd/platform/server.go

@@ -75,6 +75,13 @@ func runServer(configFileLocation string) {
 
 	if webappDir, ok := utils.FindDir(model.CLIENT_DIR); ok {
 		a.InitPlugins(*a.Config().PluginSettings.Directory, webappDir+"/plugins")
+		utils.AddConfigListener(func(prevCfg, cfg *model.Config) {
+			if *cfg.PluginSettings.Enable {
+				a.InitPlugins(*cfg.PluginSettings.Directory, webappDir+"/plugins")
+			} else {
+				a.ShutDownPlugins()
+			}
+		})
 	} else {
 		l4g.Error("Unable to find webapp directory, could not initialize plugins")
 	}