feat: add Go migration compatibility foundation

backend/cmd/zhinian-api/main.go

@@ -0,0 +1,79 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log"
+	"net"
+	"net/http"
+	"os"
+	"os/signal"
+	"strings"
+	"syscall"
+	"time"
+
+	"git.nianxx.cn/wangxuming/NianAIGC/backend/internal/application"
+)
+
+const shutdownTimeout = 10 * time.Second
+
+func main() {
+	if err := run(); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func run() error {
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer stop()
+
+	app, err := application.New(application.Options{Context: ctx})
+	if err != nil {
+		return fmt.Errorf("initialize Go backend: %w", err)
+	}
+	defer app.Close()
+
+	server := &http.Server{
+		Addr:              listenAddress(os.Getenv),
+		Handler:           app.Handler(),
+		ReadHeaderTimeout: 5 * time.Second,
+	}
+
+	serveErr := make(chan error, 1)
+	go func() {
+		log.Printf("zhinian-api foundation listening on %s", server.Addr)
+		serveErr <- server.ListenAndServe()
+	}()
+
+	select {
+	case err := <-serveErr:
+		if errors.Is(err, http.ErrServerClosed) {
+			return nil
+		}
+		return fmt.Errorf("serve Go backend: %w", err)
+	case <-ctx.Done():
+	}
+
+	shutdownCtx, cancel := context.WithTimeout(context.Background(), shutdownTimeout)
+	defer cancel()
+	if err := server.Shutdown(shutdownCtx); err != nil {
+		return fmt.Errorf("shut down Go backend: %w", err)
+	}
+	if err := <-serveErr; err != nil && !errors.Is(err, http.ErrServerClosed) {
+		return fmt.Errorf("serve Go backend: %w", err)
+	}
+	return nil
+}
+
+func listenAddress(getenv func(string) string) string {
+	host := strings.TrimSpace(getenv("GO_BACKEND_HOST"))
+	if host == "" {
+		host = "127.0.0.1"
+	}
+	port := strings.TrimSpace(getenv("GO_BACKEND_PORT"))
+	if port == "" {
+		port = "8080"
+	}
+	return net.JoinHostPort(host, port)
+}

backend/cmd/zhinian-api/main_test.go

@@ -0,0 +1,13 @@
+package main
+
+import "testing"
+
+func TestListenAddressDefaultsToLoopbackAndSupportsExplicitBinding(t *testing.T) {
+	if got := listenAddress(func(string) string { return "" }); got != "127.0.0.1:8080" {
+		t.Fatalf("listenAddress(defaults) = %q", got)
+	}
+	values := map[string]string{"GO_BACKEND_HOST": "0.0.0.0", "GO_BACKEND_PORT": "9080"}
+	if got := listenAddress(func(name string) string { return values[name] }); got != "0.0.0.0:9080" {
+		t.Fatalf("listenAddress(explicit) = %q", got)
+	}
+}