Add ability to have several servers
diff --git a/core/kg/server/servers.go b/core/kg/server/servers.go
new file mode 100644
index 0000000..d197666
--- /dev/null
+++ b/core/kg/server/servers.go
@@ -0,0 +1,69 @@
+package server
+
+import (
+	"os"
+
+	"github.com/giolekva/pcloud/core/kg/log"
+	"github.com/vardius/shutdown"
+)
+
+// Server interface
+type Server interface {
+	Start() error
+	Shutdown() error
+}
+
+// Servers represents different server services
+type Servers struct {
+	servers []Server
+	logger  *log.Logger
+}
+
+// New provides new service application
+func New(logger *log.Logger) *Servers {
+	return &Servers{
+		logger: logger,
+	}
+}
+
+// AddServers adds servers to service
+func (ss *Servers) AddServers(servers ...Server) {
+	ss.servers = append(ss.servers, servers...)
+}
+
+// Run runs the service application
+func (ss *Servers) Run() {
+	for _, server := range ss.servers {
+		go func(server Server) {
+			if err := server.Start(); err != nil {
+				ss.logger.Error("can't start server", log.Err(err))
+				os.Exit(1)
+			}
+		}(server)
+	}
+	shutdown.GracefulStop(func() { ss.shutdown() })
+}
+
+func (ss *Servers) shutdown() {
+	ss.logger.Info("shutting down...")
+
+	errCh := make(chan error, len(ss.servers))
+
+	for _, server := range ss.servers {
+		go func(server Server) {
+			errCh <- server.Shutdown()
+		}(server)
+	}
+
+	for i := 0; i < len(ss.servers); i++ {
+		if err := <-errCh; err != nil {
+			go func(err error) {
+				ss.logger.Error("shutdown error", log.Err(err))
+				os.Exit(1)
+			}(err)
+			return
+		}
+	}
+
+	ss.logger.Info("gracefully stopped")
+}