feat: first commit

backend/cmd/snip/main.go

@@ -0,0 +1,100 @@
+// Command snip is a single binary exposing three subcommands — api, frontend
+// and redirect — so one Docker image can back three docker-compose services.
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"github.com/snip/backend/internal/adapter/postgres"
+	"github.com/snip/backend/internal/config"
+	"github.com/snip/backend/internal/di"
+)
+
+func main() {
+	log.SetFlags(log.LstdFlags | log.Lmsgprefix)
+	if len(os.Args) < 2 {
+		usage()
+		os.Exit(2)
+	}
+
+	cmd := os.Args[1]
+	cfg := config.Load()
+	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
+	defer stop()
+
+	container := di.New(cfg)
+
+	var (
+		app  *di.App
+		addr string
+		err  error
+	)
+	switch cmd {
+	case "migrate":
+		if cfg.Store != "postgres" {
+			log.Printf("snip migrate: STORE=%s, nothing to do", cfg.Store)
+			os.Exit(0)
+		}
+		if err := postgres.Migrate(ctx, cfg.DatabaseURL); err != nil {
+			log.Fatalf("snip migrate: %v", err)
+		}
+		log.Println("snip migrate: schema is up to date")
+		os.Exit(0)
+	case "frontend":
+		app, addr = container.BuildFrontend(), listenAddr("8081")
+	case "api":
+		app, err = container.BuildAPI(ctx)
+		addr = listenAddr("8080")
+	case "redirect":
+		app, err = container.BuildRedirect(ctx)
+		addr = listenAddr("8082")
+	default:
+		usage()
+		os.Exit(2)
+	}
+	if err != nil {
+		log.Fatalf("snip %s: startup failed: %v", cmd, err)
+	}
+	defer app.Close()
+
+	serve(ctx, cmd, addr, app.Handler)
+}
+
+func listenAddr(def string) string {
+	if p := os.Getenv("PORT"); p != "" {
+		return ":" + p
+	}
+	return ":" + def
+}
+
+func serve(ctx context.Context, name, addr string, h http.Handler) {
+	srv := &http.Server{
+		Addr:              addr,
+		Handler:           h,
+		ReadHeaderTimeout: 5 * time.Second,
+	}
+	go func() {
+		log.Printf("snip %s listening on %s", name, addr)
+		if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
+			log.Fatalf("snip %s: %v", name, err)
+		}
+	}()
+
+	<-ctx.Done()
+	log.Printf("snip %s: shutting down", name)
+	shutCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	_ = srv.Shutdown(shutCtx)
+}
+
+func usage() {
+	fmt.Fprintln(os.Stderr, "usage: snip <migrate|api|frontend|redirect>")
+}