feat(webdemo): add database-backed usage dashboard

cmd/webdemo/main.go

@@ -12,15 +12,26 @@ import (
 
 func main() {
 	listen := flag.String("listen", "127.0.0.1:8320", "HTTP listen address")
-	input := flag.String("input", "", "data input; supported value: fake")
+	inputName := flag.String("input", "", "demo input; supported value: fake")
+	databasePath := flag.String("database", "", "optional SQLite data source for the fake demo")
 	flag.Parse()
 
-	if *input != "fake" {
+	if *inputName != "fake" {
 		fmt.Fprintln(os.Stderr, "missing supported -input value: fake")
 		os.Exit(2)
 	}
 
-	server := &http.Server{Addr: *listen, Handler: webdemo.NewServer(webdemo.NewFakeInput())}
+	var input webdemo.Input = webdemo.NewFakeInput()
+	if *databasePath != "" {
+		databaseInput, err := webdemo.NewDatabaseInput(*databasePath)
+		if err != nil {
+			log.Fatal(err)
+		}
+		input = databaseInput
+		defer databaseInput.Close()
+	}
+
+	server := &http.Server{Addr: *listen, Handler: webdemo.NewServer(input)}
 	log.Printf("billing web demo: http://%s/ui", *listen)
 	log.Fatal(server.ListenAndServe())
 }