stub out webapp & Set up a go skeleton that works with the underlying FE js

main.go

@@ -0,0 +1,109 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"log"
+	"net/http"
+	"os"
+	"os/exec"
+	"os/signal"
+	"path/filepath"
+	"sync"
+	"syscall"
+	"time"
+)
+
+var (
+	devMode = flag.Bool("dev", false, "Run yarn autoreload underneath Go")
+)
+
+const (
+	publicWebPath = "./web/public/"
+)
+
+func main() {
+	flag.Parse()
+	var wg sync.WaitGroup
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, os.Interrupt)
+
+	ctx, cancel := context.WithCancel(context.Background())
+
+	go func() {
+		oscall := <-c
+		log.Printf("system call:%+v", oscall)
+		cancel()
+	}()
+
+	wg.Add(1)
+	go serveHTTP(ctx, &wg)
+	if *devMode {
+		wg.Add(1)
+		go runYarn(ctx, &wg)
+	}
+	wg.Wait()
+}
+
+func serveHTTP(ctx context.Context, wg *sync.WaitGroup) {
+
+	fs := http.FileServer(http.Dir(publicWebPath))
+	mux := http.NewServeMux()
+	mux.Handle("/", fs)
+
+	srv := &http.Server{
+		Addr:    ":5000",
+		Handler: mux,
+	}
+
+	go func() {
+		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			log.Fatalf("listen:%+s\n", err)
+		}
+	}()
+
+	log.Printf("Listening on port :5000")
+
+	<-ctx.Done()
+
+	log.Printf("server stopped")
+
+	ctxShutDown, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	if err := srv.Shutdown(ctxShutDown); err != nil {
+		if err != http.ErrServerClosed {
+			log.Fatalf("server Shutdown Failed:%+s", err)
+		}
+	}
+
+	log.Printf("server exited properly")
+
+	wg.Done()
+	return
+}
+
+func runYarn(ctx context.Context, wg *sync.WaitGroup) {
+	var err error
+	cmd := exec.Command("yarn", "dev")
+	cmd.Env = append(cmd.Env, "SKIP_SERVE=1")
+	cmd.Dir, err = filepath.Abs("./web/")
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	if err != nil {
+		panic(err)
+	}
+	err = cmd.Start()
+	if err != nil {
+		panic(err)
+	}
+	<-ctx.Done()
+	log.Println("closing")
+	err = syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL)
+	if err != nil {
+		panic(err)
+	}
+	wg.Done()
+	return
+}