Add new RPC helpers wrapping over regular rpc packages, add middleware chaining ability

pkg/server/router.go

@@ -20,11 +20,11 @@ import (
 	"net/http"
 
 	router "github.com/gorilla/mux"
-	jsonRPC "github.com/gorilla/rpc/v2"
 	"github.com/minio/minio/pkg/server/api"
 	"github.com/minio/minio/pkg/server/rpc"
 )
 
+// registerAPI - register all the object API handlers to their respective paths
 func registerAPI(mux *router.Router) http.Handler {
 	api := api.MinioAPI{}
 
@@ -50,28 +50,68 @@ func registerAPI(mux *router.Router) http.Handler {
 	return mux
 }
 
-func registerOthers(mux http.Handler, conf api.Config) http.Handler {
-	mux = api.ValidContentTypeHandler(mux)
-	mux = api.TimeValidityHandler(mux)
-	mux = api.IgnoreResourcesHandler(mux)
-	mux = api.ValidateAuthHeaderHandler(mux)
+// add a handlerFunc typedef
+type handlerFunc func(http.Handler) http.Handler
+
+// chain struct to hold handlers
+type chain struct {
+	handlers []handlerFunc
+}
+
+// loop through handlers and return a final one
+func (c chain) final(mux http.Handler) http.Handler {
+	var f http.Handler
+	if mux != nil {
+		f = mux
+	} else {
+		f = http.DefaultServeMux
+	}
+	for _, handler := range c.handlers {
+		f = handler(f)
+	}
+	return f
+}
+
+// registerChain - register an array of handlers in a chain of style -> handler(handler(handler(handler...)))
+func registerChain(handlers ...handlerFunc) chain {
+	ch := chain{}
+	ch.handlers = append(ch.handlers, handlers...)
+	return ch
+}
+
+// registerOtherMiddleware register all available middleware
+func registerOtherMiddleware(mux http.Handler, conf api.Config) http.Handler {
+	ch := registerChain(
+		api.ValidContentTypeHandler,
+		api.TimeValidityHandler,
+		api.IgnoreResourcesHandler,
+		api.ValidateAuthHeaderHandler,
+		api.LoggingHandler,
+		// Add new middleware here
+	)
+
+	mux = ch.final(mux)
 	mux = api.RateLimitHandler(mux, conf.RateLimit)
-	mux = api.LoggingHandler(mux)
 	return mux
 }
 
-func registerRPC(mux *router.Router, r *jsonRPC.Server) http.Handler {
-	mux.Handle("/rpc", r)
+// registerRPC - register rpc handlers
+func registerRPC(mux *router.Router, s *rpc.Server) http.Handler {
+	mux.Handle("/rpc", s)
 	return mux
 }
 
 // APIHandler api handler
 func APIHandler(conf api.Config) http.Handler {
 	mux := router.NewRouter()
-	return registerOthers(registerAPI(mux), conf)
+	return registerOtherMiddleware(registerAPI(mux), conf)
 }
 
 // RPCHandler rpc handler
 func RPCHandler() http.Handler {
-	return registerRPC(router.NewRouter(), rpc.HelloServiceHandler())
+	s := rpc.NewServer()
+	s.RegisterJSONCodec()
+	s.RegisterService(new(rpc.HelloService), "")
+	// add more services here
+	return registerRPC(router.NewRouter(), s)
 }

pkg/server/rpc/server.go

@@ -17,14 +17,35 @@
 package rpc
 
 import (
+	"net/http"
+
 	"github.com/gorilla/rpc/v2"
 	"github.com/gorilla/rpc/v2/json"
 )
 
-// HelloServiceHandler -
-func HelloServiceHandler() *rpc.Server {
-	s := rpc.NewServer()
-	s.RegisterCodec(json.NewCodec(), "application/json")
-	s.RegisterService(new(HelloService), "")
+// Server rpc server container
+type Server struct {
+	RPCServer *rpc.Server
+}
+
+// RegisterJSONCodec - register standard json codec
+func (s Server) RegisterJSONCodec() {
+	s.RPCServer.RegisterCodec(json.NewCodec(), "application/json")
+}
+
+// RegisterService - register new services
+func (s Server) RegisterService(recv interface{}, name string) {
+	s.RPCServer.RegisterService(recv, name)
+}
+
+// NewServer - provide a new instance of RPC server
+func NewServer() *Server {
+	s := &Server{}
+	s.RPCServer = rpc.NewServer()
 	return s
 }
+
+// ServeHTTP wrapper method for http.Handler interface
+func (s Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	s.RPCServer.ServeHTTP(w, r)
+}

pkg/server/server.go

@@ -28,7 +28,6 @@ import (
 func startAPI(errCh chan error, conf api.Config) {
 	defer close(errCh)
 
-	var err error
 	// Minio server config
 	httpServer := &http.Server{
 		Addr:           conf.Address,
@@ -66,37 +65,26 @@ func startAPI(errCh chan error, conf api.Config) {
 		for _, host := range hosts {
 			fmt.Printf("Starting minio server on: http://%s:%s\n", host, port)
 		}
-		err = httpServer.ListenAndServe()
+		errCh <- httpServer.ListenAndServe()
 	case conf.TLS == true:
 		for _, host := range hosts {
 			fmt.Printf("Starting minio server on: https://%s:%s\n", host, port)
 		}
-		err = httpServer.ListenAndServeTLS(conf.CertFile, conf.KeyFile)
+		errCh <- httpServer.ListenAndServeTLS(conf.CertFile, conf.KeyFile)
 	}
-	if err != nil {
-		errCh <- err
-	}
-	errCh <- nil
-	return
 }
 
 func startRPC(errCh chan error) {
 	defer close(errCh)
 
 	rpcHandler := RPCHandler()
-	var err error
 	// Minio server config
 	httpServer := &http.Server{
-		Addr:           "127.0.0.1:9001",
+		Addr:           "127.0.0.1:9001", // TODO make this configurable
 		Handler:        rpcHandler,
 		MaxHeaderBytes: 1 << 20,
 	}
-	err = httpServer.ListenAndServe()
-	if err != nil {
-		errCh <- err
-	}
-	errCh <- nil
-	return
+	errCh <- httpServer.ListenAndServe()
 }
 
 // StartServices starts basic services for a server
@@ -109,13 +97,8 @@ func StartServices(conf api.Config) error {
 
 	select {
 	case err := <-apiErrCh:
-		if err != nil {
-			return err
-		}
+		return err
 	case err := <-rpcErrCh:
-		if err != nil {
-			return err
-		}
+		return err
 	}
-	return nil
 }