add handler switcher instead of Manners

Signed-off-by: Emile Vauge <emile@vauge.com>

middlewares/handlerSwitcher.go

@@ -0,0 +1,40 @@
+package middlewares
+
+import (
+	"github.com/gorilla/mux"
+	"net/http"
+	"sync"
+)
+
+// HandlerSwitcher allows hot switching of http.ServeMux
+type HandlerSwitcher struct {
+	handler     *mux.Router
+	handlerLock *sync.Mutex
+}
+
+// NewHandlerSwitcher builds a new instance of HandlerSwitcher
+func NewHandlerSwitcher(newHandler *mux.Router) (hs *HandlerSwitcher) {
+	return &HandlerSwitcher{
+		handler:     newHandler,
+		handlerLock: &sync.Mutex{},
+	}
+}
+
+func (hs *HandlerSwitcher) ServeHTTP(rw http.ResponseWriter, r *http.Request) {
+	hs.handlerLock.Lock()
+	handlerBackup := hs.handler
+	hs.handlerLock.Unlock()
+	handlerBackup.ServeHTTP(rw, r)
+}
+
+// GetHandler returns the current http.ServeMux
+func (hs *HandlerSwitcher) GetHandler() (newHandler *mux.Router) {
+	return hs.handler
+}
+
+// UpdateHandler safely updates the current http.ServeMux with a new one
+func (hs *HandlerSwitcher) UpdateHandler(newHandler *mux.Router) {
+	hs.handlerLock.Lock()
+	hs.handler = newHandler
+	defer hs.handlerLock.Unlock()
+}