HTTPServer: Implement named middlewares (#44231)

* Implement named middlewares on http server

* Fix minor ordering issue with named middlewares

pkg/api/http_server.go

@@ -70,6 +70,7 @@ type HTTPServer struct {
 	context          context.Context
 	httpSrv          *http.Server
 	middlewares      []web.Handler
+	namedMiddlewares []routing.RegisterNamedMiddleware
 
 	PluginContextProvider     *plugincontext.Provider
 	RouteRegister             routing.RouteRegister
@@ -214,6 +215,10 @@ func (hs *HTTPServer) AddMiddleware(middleware web.Handler) {
 	hs.middlewares = append(hs.middlewares, middleware)
 }
 
+func (hs *HTTPServer) AddNamedMiddleware(middleware routing.RegisterNamedMiddleware) {
+	hs.namedMiddlewares = append(hs.namedMiddlewares, middleware)
+}
+
 func (hs *HTTPServer) Run(ctx context.Context) error {
 	hs.context = ctx
 
@@ -400,7 +405,7 @@ func (hs *HTTPServer) applyRoutes() {
 	// start with middlewares & static routes
 	hs.addMiddlewaresAndStaticRoutes()
 	// then add view routes & api routes
-	hs.RouteRegister.Register(hs.web)
+	hs.RouteRegister.Register(hs.web, hs.namedMiddlewares...)
 	// then custom app proxy routes
 	hs.initAppPluginRoutes(hs.web)
 	// lastly not found route

pkg/api/routing/route_register.go

@@ -44,7 +44,7 @@ type RouteRegister interface {
 
 	// Register iterates over all routes added to the RouteRegister
 	// and add them to the `Router` pass as an parameter.
-	Register(Router)
+	Register(Router, ...RegisterNamedMiddleware)
 
 	// Reset resets the route register.
 	Reset()
@@ -118,8 +118,13 @@ func (rr *RouteRegisterImpl) Group(pattern string, fn func(rr RouteRegister), ha
 	rr.groups = append(rr.groups, group)
 }
 
-func (rr *RouteRegisterImpl) Register(router Router) {
+func (rr *RouteRegisterImpl) Register(router Router, namedMiddlewares ...RegisterNamedMiddleware) {
 	for _, r := range rr.routes {
+		// Add global named middlewares
+		for i, m := range namedMiddlewares {
+			r.handlers = insertHandler(r.handlers, len(rr.namedMiddlewares)+i, m(r.pattern))
+		}
+
 		// GET requests have to be added to macaron routing using Get()
 		// Otherwise HEAD requests will not be allowed.
 		// https://github.com/go-macaron/macaron/blob/a325110f8b392bce3e5cdeb8c44bf98078ada3be/router.go#L198
@@ -131,7 +136,7 @@ func (rr *RouteRegisterImpl) Register(router Router) {
 	}
 
 	for _, g := range rr.groups {
-		g.Register(router)
+		g.Register(router, namedMiddlewares...)
 	}
 }
 
@@ -159,6 +164,15 @@ func (rr *RouteRegisterImpl) route(pattern, method string, handlers ...web.Handl
 	})
 }
 
+func insertHandler(a []web.Handler, index int, value web.Handler) []web.Handler {
+	if len(a) == index {
+		return append(a, value)
+	}
+	a = append(a[:index+1], a[index:]...)
+	a[index] = value
+	return a
+}
+
 func (rr *RouteRegisterImpl) Get(pattern string, handlers ...web.Handler) {
 	rr.route(pattern, http.MethodGet, handlers...)
 }

pkg/cmd/grafana-cli/runner/wire.go

@@ -73,6 +73,6 @@ func (noOpRouteRegister) Group(string, func(routing.RouteRegister), ...web.Handl
 
 func (noOpRouteRegister) Insert(string, func(routing.RouteRegister), ...web.Handler) {}
 
-func (noOpRouteRegister) Register(routing.Router) {}
+func (noOpRouteRegister) Register(routing.Router, ...routing.RegisterNamedMiddleware) {}
 
 func (noOpRouteRegister) Reset() {}