site and webhooks packages stubbed

main.go

@@ -0,0 +1,127 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"ruben/inventory2/internal/site"
+	"ruben/inventory2/internal/webhooks"
+)
+
+func main() {
+	if err := runApp(context.Background()); err != nil {
+		panic(err)
+	}
+	fmt.Println("application shutdown")
+}
+
+func runApp(ctx context.Context) error {
+	ctx, shutdown := context.WithCancel(ctx)
+	defer shutdown()
+
+	// start http server
+
+	srvErrCh := runServer(ctx)
+
+	// wait for interrupt signal or unrecoverable failure, then shutdown
+
+	osSignalCh := make(chan os.Signal, 1)
+	signal.Notify(osSignalCh, syscall.SIGINT, syscall.SIGTERM)
+
+	var serverAlreadyShutdown bool
+	select {
+	case s := <-osSignalCh:
+		fmt.Println("application received shutdown signal:", s)
+		fmt.Println("shutting down")
+	case err := <-srvErrCh:
+		serverAlreadyShutdown = true
+		fmt.Println("server shutdown unexpectedly")
+		if err != nil {
+			fmt.Println("server encountered error:", err)
+		}
+	}
+
+	shutdown()
+
+	// capture application errors that occurred during or caused shutdown
+
+	var errs []error
+
+	if !serverAlreadyShutdown {
+		if err := <-srvErrCh; err != nil {
+			errs = append(errs, fmt.Errorf("server experienced an error: %w", err))
+		}
+		fmt.Println("server shut down")
+	}
+
+	return errors.Join(errs...)
+}
+
+func buildHTTPHandler() http.Handler {
+	mux := http.NewServeMux()
+
+	mux.Handle("/webhooks/", http.StripPrefix("/webhooks", webhooks.New()))
+	mux.Handle("/site/", http.StripPrefix("/site", site.NewSiteHandler()))
+
+	return mux
+}
+
+func runServer(ctx context.Context) <-chan error {
+	srv := &http.Server{
+		Addr:    ":9000", // local
+		Handler: buildHTTPHandler(),
+	}
+
+	ctx, cancel := context.WithCancel(ctx)
+	alreadyShutdownCh := make(chan struct{}, 1)
+
+	runningErrCh := make(chan error, 1)
+	go func() {
+		defer close(runningErrCh)
+		defer cancel()
+		defer close(alreadyShutdownCh)
+
+		fmt.Println("server running on 9000...")
+		if err := srv.ListenAndServe(); err != nil {
+			if !errors.Is(err, http.ErrServerClosed) {
+				runningErrCh <- fmt.Errorf("server experienced error: %w", err)
+			}
+		}
+	}()
+
+	shutdownErrCh := make(chan error, 1)
+	go func() {
+		defer close(shutdownErrCh)
+
+		select {
+		case <-alreadyShutdownCh:
+			return
+		case <-ctx.Done():
+		}
+
+		shutdownCtx, cancelShutdown := context.WithTimeout(context.Background(), 60*time.Second)
+		defer cancelShutdown()
+		if err := srv.Shutdown(shutdownCtx); err != nil {
+			shutdownErrCh <- fmt.Errorf("error occurred attempting to shutdown server: %w", err)
+		}
+	}()
+
+	errCh := make(chan error, 1)
+	go func() {
+		defer close(errCh)
+
+		err1 := <-runningErrCh
+		err2 := <-shutdownErrCh
+		if err := errors.Join(err1, err2); err != nil {
+			errCh <- err
+		}
+	}()
+
+	return errCh
+}