merged from gramsrv upstream

cmd/telesrv-update/main.go

@@ -0,0 +1,109 @@
+// Command telesrv-update serves native Telegram client update metadata and
+// immutable, range-enabled desktop update packages.
+package main
+
+import (
+	"context"
+	"errors"
+	"flag"
+	"fmt"
+	"net"
+	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"go.uber.org/zap"
+
+	"telesrv/internal/updatecdn"
+)
+
+func main() {
+	if err := run(); err != nil {
+		fmt.Fprintln(os.Stderr, "telesrv-update:", err)
+		os.Exit(1)
+	}
+}
+
+func run() error {
+	listenDefault := envOr("TELESRV_UPDATE_LISTEN", "127.0.0.1:2402")
+	manifestDefault := envOr("TELESRV_UPDATE_MANIFEST", "data/updates/manifest.json")
+	filesDefault := envOr("TELESRV_UPDATE_FILES_DIR", "data/updates/files")
+
+	listenAddr := flag.String("listen", listenDefault, "HTTP listen address")
+	manifestPath := flag.String("manifest", manifestDefault, "release manifest path")
+	filesDir := flag.String("files", filesDefault, "desktop update package directory")
+	check := flag.Bool("check", false, "validate the catalog and exit")
+	flag.Parse()
+
+	store, err := updatecdn.NewStore(*manifestPath, *filesDir)
+	if err != nil {
+		return fmt.Errorf("load update catalog: %w", err)
+	}
+	if *check {
+		fmt.Println("update catalog is valid")
+		return nil
+	}
+	handler, err := updatecdn.NewHandler(store)
+	if err != nil {
+		return err
+	}
+	listener, err := net.Listen("tcp", *listenAddr)
+	if err != nil {
+		return fmt.Errorf("listen on %s: %w", *listenAddr, err)
+	}
+
+	logger, err := zap.NewProduction()
+	if err != nil {
+		_ = listener.Close()
+		return fmt.Errorf("initialize logger: %w", err)
+	}
+	defer logger.Sync() //nolint:errcheck
+
+	server := &http.Server{
+		Handler:           handler,
+		ReadHeaderTimeout: 5 * time.Second,
+		ReadTimeout:       30 * time.Second,
+		WriteTimeout:      5 * time.Minute,
+		IdleTimeout:       2 * time.Minute,
+		MaxHeaderBytes:    32 << 10,
+	}
+	serveErr := make(chan error, 1)
+	go func() {
+		serveErr <- server.Serve(listener)
+	}()
+	logger.Info("update service started",
+		zap.String("listen", listener.Addr().String()),
+		zap.String("manifest", *manifestPath),
+		zap.String("files", *filesDir))
+
+	stopCtx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer stop()
+	select {
+	case err := <-serveErr:
+		if errors.Is(err, http.ErrServerClosed) {
+			return nil
+		}
+		return fmt.Errorf("serve HTTP: %w", err)
+	case <-stopCtx.Done():
+	}
+
+	shutdownCtx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
+	defer cancel()
+	if err := server.Shutdown(shutdownCtx); err != nil {
+		return fmt.Errorf("shutdown HTTP server: %w", err)
+	}
+	if err := <-serveErr; err != nil && !errors.Is(err, http.ErrServerClosed) {
+		return fmt.Errorf("serve HTTP: %w", err)
+	}
+	logger.Info("update service stopped")
+	return nil
+}
+
+func envOr(key, fallback string) string {
+	if value, ok := os.LookupEnv(key); ok && value != "" {
+		return value
+	}
+	return fallback
+}