implement shutodwn and imrprove logging

gemini/gemini.go

@@ -49,6 +49,7 @@ var (
 	ErrServerClosed  = errors.New("gemini: server closed")
 	ErrHeaderTooLong = errors.New("gemini: header too long")
 	ErrMissingFile   = errors.New("gemini: no such file")
+	ErrEmptyRequest  = errors.New("gemini: empty request")
 )
 
 type Request struct {
@@ -90,6 +91,11 @@ type Server struct {
 	Handler      Handler // handler to invoke
 	ReadTimeout  time.Duration
 	MaxOpenConns int
+
+	// internal
+	listener net.Listener
+	shutdown bool
+	closed   chan struct{}
 }
 
 func (s *Server) log(v string) {
@@ -107,10 +113,13 @@ func (s *Server) logf(format string, v ...interface{}) {
 }
 
 func (s *Server) ListenAndServe() error {
+	s.closed = make(chan struct{})
+
 	// outer for loop, if listener closes we will restart it. This may be useful if we switch out
 	// TLSConfig.
 	//for {
-	listener, err := tls.Listen("tcp", s.Addr, s.TLSConfig)
+	var err error
+	s.listener, err = tls.Listen("tcp", s.Addr, s.TLSConfig)
 	if err != nil {
 		return fmt.Errorf("gemini server listen: %w", err)
 	}
@@ -119,15 +128,26 @@ func (s *Server) ListenAndServe() error {
 	go s.handleConnectionQueue(queue)
 
 	for {
-		conn, err := listener.Accept()
+		conn, err := s.listener.Accept()
 		if err != nil {
 			s.logf("server accept error: %v", err)
 			break
 		}
 		queue <- conn
+
+		// un-stuck call after shutdown will trigger a drop here
+		if s.shutdown {
+			break
+		}
 	}
+	// closed confirms the accept call stopped
+	close(s.closed)
+	//if s.shutdown {
+	//	return nil
 	//}
-	return nil
+	//}
+	s.log("closing listener gracefully")
+	return s.listener.Close()
 }
 
 func (s *Server) handleConnectionQueue(queue chan net.Conn) {
@@ -171,6 +191,11 @@ func (s *Server) handleConnection(conn net.Conn, sem chan struct{}) {
 }
 
 func (s *Server) handleRequestError(conn net.Conn, req request) {
+	if errors.Is(req.err, ErrEmptyRequest) {
+		// silently ignore empty requests.
+		return
+	}
+
 	s.logf("server error: '%s' %v", strings.TrimSpace(req.rawuri), req.err)
 
 	var gmierr *GmiError
@@ -192,17 +217,22 @@ type request struct {
 }
 
 func requestChannel(c net.Conn, rsp chan request) {
+	req := &request{}
 	r, err := readHeader(c)
-	r.err = err
-	rsp <- *r
+	if r != nil {
+		req = r
+	}
+	req.err = err
+	rsp <- *req
 }
 
 func readHeader(c net.Conn) (*request, error) {
-	r := &request{}
 	req, err := bufio.NewReader(c).ReadString('\r')
 	if err != nil {
-		return nil, Error(StatusTemporaryFailure, errors.New("error reading request"))
+		return nil, Error(StatusTemporaryFailure, ErrEmptyRequest)
 	}
+
+	r := &request{}
 	r.rawuri = req
 
 	requestURL := strings.TrimSpace(req)
@@ -237,7 +267,30 @@ func readHeader(c net.Conn) (*request, error) {
 }
 
 func (s *Server) Shutdown(ctx context.Context) error {
+	s.log("shutdown request received")
+	t := time.Now()
+	go func() {
+		s.shutdown = true
+		// un-stuck call to self
+		conn, err := tls.Dial("tcp", "localhost:1965", &tls.Config{
+			InsecureSkipVerify: true,
+		})
+		if err != nil {
+			s.logf("un-stuck call error: %v", err)
+			return
+		}
+		defer conn.Close()
+	}()
 
+	select {
+	case <-s.closed:
+		s.log("all clients exited")
+	case <-ctx.Done():
+		s.logf("shutdown: context deadline exceeded after %v, terminating listener", time.Since(t))
+		if err := s.listener.Close(); err != nil {
+			s.logf("error while closing listener %v", err)
+		}
+	}
 	return nil
 }
 

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"context"
 	"crypto/tls"
 	"errors"
 	"flag"
@@ -10,6 +11,7 @@ import (
 	"log"
 	"mime"
 	"os"
+	"os/signal"
 	"path"
 	"path/filepath"
 	"strings"
@@ -47,7 +49,7 @@ func main() {
 	flag.Parse()
 
 	// TODO: rotate on SIGHUP
-	flogger := log.New(os.Stdout, "", log.LUTC|log.Ldate|log.Ltime)
+	mlogger := log.New(os.Stdout, "", log.LUTC|log.Ldate|log.Ltime)
 	if logs != "" {
 		logpath := filepath.Join(logs, "access.log")
 		accessLog, err := os.OpenFile(logpath, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0644)
@@ -56,7 +58,7 @@ func main() {
 		}
 		defer accessLog.Close()
 
-		flogger.SetOutput(accessLog)
+		mlogger.SetOutput(accessLog)
 	}
 
 	var dlogger *log.Logger
@@ -98,7 +100,7 @@ func main() {
 	}
 
 	mux := gemini.NewMux()
-	mux.Use(logger(flogger))
+	mux.Use(logger(mlogger))
 	mux.Handle(gemini.HandlerFunc(fileserver(root)))
 
 	server := &gemini.Server{
@@ -111,29 +113,27 @@ func main() {
 		Logger:       dlogger,
 	}
 
-	//confirm := make(chan struct{}, 1)
-	//go func() {
-	if err := server.ListenAndServe(); err != nil && !errors.Is(err, gemini.ErrServerClosed) {
-		log.Fatal("ListenAndServe terminated unexpectedly")
+	confirm := make(chan struct{}, 1)
+	go func() {
+		if err := server.ListenAndServe(); err != nil && !errors.Is(err, gemini.ErrServerClosed) {
+			log.Fatalf("ListenAndServe terminated unexpectedly: %v", err)
+		}
+		close(confirm)
+	}()
+
+	stop := make(chan os.Signal, 1)
+	signal.Notify(stop, os.Interrupt)
+	<-stop
+
+	ctx, cancel := context.WithTimeout(context.Background(), shutdownTimeout)
+	if err := server.Shutdown(ctx); err != nil {
+		cancel()
+		log.Fatal("ListenAndServe shutdown")
 	}
 
-	//	close(confirm)
-	//}()
+	<-confirm
+	cancel()
 
-	/*
-		stop := make(chan os.Signal, 1)
-		signal.Notify(stop, os.Interrupt)
-		<-stop
-
-		ctx, cancel := context.WithTimeout(context.Background(), shutdownTimeout)
-		if err := server.Shutdown(ctx); err != nil {
-			cancel()
-			log.Fatal("ListenAndServe shutdown")
-		}
-
-		<-confirm
-		cancel()
-	*/
 	/*
 		hup := make(chan os.Signal, 1)
 		signal.Notify(hup, syscall.SIGHUP)
@@ -154,7 +154,7 @@ func logger(log *log.Logger) func(next gemini.Handler) gemini.Handler {
 
 			ip := strings.Split(r.RemoteAddr, ":")[0]
 			hostname, _ := os.Hostname()
-			fmt.Printf("%s %s - - [%s] \"%s\" - %v\n",
+			fmt.Fprintf(log.Writer(), "%s %s - - [%s] \"%s\" - %v\n",
 				hostname,
 				ip,
 				t.Format("02/Jan/2006:15:04:05 -0700"),