feat(backend): main wiring, graceful shutdown, local smoke green

backend/cmd/server/main.go

@@ -0,0 +1,62 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"log"
+	"net/http"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"booklib/internal/api"
+	"booklib/internal/config"
+	"booklib/internal/db"
+	"booklib/internal/redispkg"
+	"booklib/internal/scanner"
+	"booklib/internal/seed"
+	"booklib/internal/store"
+)
+
+func main() {
+	cfg, err := config.Load()
+	if err != nil {
+		log.Fatalf("config: %v", err)
+	}
+	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
+	defer stop()
+
+	p, err := db.Connect(ctx, cfg.DatabaseURL)
+	if err != nil {
+		log.Fatalf("db connect: %v", err)
+	}
+	defer p.Close()
+	if err := db.Migrate(ctx, p); err != nil {
+		log.Fatalf("migrate: %v", err)
+	}
+	st := store.New(p)
+	if err := seed.Admin(ctx, st, cfg.AdminUser, cfg.AdminPassword); err != nil {
+		log.Fatalf("seed: %v", err)
+	}
+	rdb := redispkg.New(cfg.RedisURL)
+	sc := scanner.New(st, cfg, rdb)
+	go sc.Run(ctx)
+
+	srv := &http.Server{Addr: cfg.Addr, Handler: api.NewRouter(cfg, st, rdb, sc),
+		ReadHeaderTimeout: 10 * time.Second}
+	go func() {
+		log.Printf("listening on %s", cfg.Addr)
+		if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
+			log.Fatalf("serve: %v", err)
+		}
+	}()
+	<-ctx.Done()
+	// stop() 先取消 ctx → scanner 循环退出;再等 HTTP 收尾。
+	// 在途 ScanLibraryByID(WithoutCancel)不受 ctx 控制,靠 redis 锁 TTL 兜底(已文档化的上限)。
+	stop()
+	shutdownCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	if err := srv.Shutdown(shutdownCtx); err != nil {
+		log.Printf("shutdown: %v", err)
+	}
+}

backend/internal/config/config_test.go

@@ -0,0 +1,37 @@
+package config
+
+import (
+	"path/filepath"
+	"testing"
+	"time"
+)
+
+func TestLoad(t *testing.T) {
+	// 屏蔽外部 env,保证默认值断言自洽(Load 将空串视为未设置)
+	t.Setenv("BOOKS_DIR", "")
+	t.Setenv("CACHE_DIR", "")
+	t.Setenv("ADDR", "")
+	t.Setenv("JWT_SECRET", "")
+	if _, err := Load(); err == nil {
+		t.Fatal("missing JWT_SECRET must fail")
+	}
+	t.Setenv("JWT_SECRET", "x")
+	t.Setenv("SCAN_INTERVAL_SEC", "abc")
+	if _, err := Load(); err == nil {
+		t.Fatal("bad interval must fail")
+	}
+	t.Setenv("SCAN_INTERVAL_SEC", "30")
+	t.Setenv("DATABASE_URL", "postgres://x")
+	c, err := Load()
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Load 会 EvalSymlinks 解析 BooksDir(任务10 裁定),这里做同样的期望值解析
+	wantBooks := "/data/books"
+	if r, e := filepath.EvalSymlinks(wantBooks); e == nil {
+		wantBooks = r
+	}
+	if c.ScanInterval != 30*time.Second || c.BooksDir != wantBooks || c.Addr != ":8080" {
+		t.Fatalf("%+v", c)
+	}
+}