Initial commit

This commit contains skeleton of the application with
uber/fx DI library.

modules/grace/graceful.go

@@ -0,0 +1,26 @@
+package grace
+
+import (
+	"context"
+	"log"
+	"os"
+	"os/signal"
+	"syscall"
+)
+
+func NewGracefulContext() context.Context {
+	ctx, cancel := context.WithCancel(context.Background())
+
+	go func() {
+		ch := make(chan os.Signal, 1)
+		signal.Notify(ch, syscall.SIGINT, syscall.SIGTERM)
+		select {
+		case <-ch:
+			log.Print("ctx: caught interrupt signal")
+			cancel()
+		case <-ctx.Done():
+		}
+	}()
+
+	return ctx
+}