Preserve unix socket file

modules/graceful/net_unix.go

@@ -23,6 +23,7 @@ import (
 const (
 	listenFDs = "LISTEN_FDS"
 	startFD   = 3
+	unlinkFDs = "GITEA_UNLINK_FDS"
 )
 
 // In order to keep the working directory the same as when we started we record
@@ -33,8 +34,10 @@ var (
 	once  = sync.Once{}
 	mutex = sync.Mutex{}
 
-	providedListeners = []net.Listener{}
-	activeListeners   = []net.Listener{}
+	providedListenersToUnlink = []bool{}
+	activeListenersToUnlink   = []bool{}
+	providedListeners         = []net.Listener{}
+	activeListeners           = []net.Listener{}
 )
 
 func getProvidedFDs() (savedErr error) {
@@ -53,6 +56,16 @@ func getProvidedFDs() (savedErr error) {
 			return
 		}
 
+		fdsToUnlinkStr := strings.Split(os.Getenv(unlinkFDs), ",")
+		providedListenersToUnlink = make([]bool, n)
+		for _, fdStr := range fdsToUnlinkStr {
+			i, err := strconv.Atoi(fdStr)
+			if err != nil || i < 0 || i >= n {
+				continue
+			}
+			providedListenersToUnlink[i] = true
+		}
+
 		for i := startFD; i < n+startFD; i++ {
 			file := os.NewFile(uintptr(i), fmt.Sprintf("listener_FD%d", i))
 
@@ -136,8 +149,11 @@ func GetListenerTCP(network string, address *net.TCPAddr) (*net.TCPListener, err
 	for i, l := range providedListeners {
 		if isSameAddr(l.Addr(), address) {
 			providedListeners = append(providedListeners[:i], providedListeners[i+1:]...)
+			needsUnlink := providedListenersToUnlink[i]
+			providedListenersToUnlink = append(providedListenersToUnlink[:i], providedListenersToUnlink[i+1:]...)
 
 			activeListeners = append(activeListeners, l)
+			activeListenersToUnlink = append(activeListenersToUnlink, needsUnlink)
 			return l.(*net.TCPListener), nil
 		}
 	}
@@ -148,6 +164,7 @@ func GetListenerTCP(network string, address *net.TCPAddr) (*net.TCPListener, err
 		return nil, err
 	}
 	activeListeners = append(activeListeners, l)
+	activeListenersToUnlink = append(activeListenersToUnlink, false)
 	return l, nil
 }
 
@@ -166,9 +183,15 @@ func GetListenerUnix(network string, address *net.UnixAddr) (*net.UnixListener,
 	for i, l := range providedListeners {
 		if isSameAddr(l.Addr(), address) {
 			providedListeners = append(providedListeners[:i], providedListeners[i+1:]...)
+			needsUnlink := providedListenersToUnlink[i]
+			providedListenersToUnlink = append(providedListenersToUnlink[:i], providedListenersToUnlink[i+1:]...)
+
+			activeListenersToUnlink = append(activeListenersToUnlink, needsUnlink)
 			activeListeners = append(activeListeners, l)
 			unixListener := l.(*net.UnixListener)
-			unixListener.SetUnlinkOnClose(true)
+			if needsUnlink {
+				unixListener.SetUnlinkOnClose(true)
+			}
 			return unixListener, nil
 		}
 	}
@@ -189,6 +212,7 @@ func GetListenerUnix(network string, address *net.UnixAddr) (*net.UnixListener,
 	}
 
 	activeListeners = append(activeListeners, l)
+	activeListenersToUnlink = append(activeListenersToUnlink, true)
 	return l, nil
 }
 
@@ -223,3 +247,11 @@ func getActiveListeners() []net.Listener {
 	copy(listeners, activeListeners)
 	return listeners
 }
+
+func getActiveListenersToUnlink() []bool {
+	mutex.Lock()
+	defer mutex.Unlock()
+	listenersToUnlink := make([]bool, len(activeListenersToUnlink))
+	copy(listenersToUnlink, activeListenersToUnlink)
+	return listenersToUnlink
+}

modules/graceful/restart_unix.go

@@ -12,6 +12,7 @@ import (
 	"net"
 	"os"
 	"os/exec"
+	"strconv"
 	"strings"
 	"sync"
 	"syscall"
@@ -75,6 +76,20 @@ func RestartProcess() (int, error) {
 	}
 	env = append(env, fmt.Sprintf("%s=%d", listenFDs, len(listeners)))
 
+	sb := &strings.Builder{}
+	for i, unlink := range getActiveListenersToUnlink() {
+		if !unlink {
+			continue
+		}
+		_, _ = sb.WriteString(strconv.Itoa(i))
+		_, _ = sb.WriteString(",")
+	}
+	unlinkStr := sb.String()
+	if len(unlinkStr) > 0 {
+		unlinkStr = unlinkStr[:len(unlinkStr)-1]
+		env = append(env, fmt.Sprintf("%s=%s", unlinkFDs, unlinkStr))
+	}
+
 	allFiles := append([]*os.File{os.Stdin, os.Stdout, os.Stderr}, files...)
 	process, err := os.StartProcess(argv0, os.Args, &os.ProcAttr{
 		Dir:   originalWD,