Update copy.DirCopy to leave sockets open

- Closes #2113

copy.DirCopy contains code to create named sockets matching those on the
source; however, this operation closes the socket, removing it
implicitly from the destination and causing later chown and chmod
operations to fail.

This commit removes the `.close()` operation, leaving the socket in
place at the destination, as it is in the source.

Signed-off-by: Jonathon Anderson <[email protected]>

drivers/copy/copy_linux.go

@@ -199,11 +199,10 @@ func DirCopy(srcDir, dstDir string, copyMode Mode, copyXattrs bool) error {
 			}
 
 		case mode&os.ModeSocket != 0:
-			s, err := net.Listen("unix", dstPath)
+			_, err := net.Listen("unix", dstPath)
 			if err != nil {
 				return err
 			}
-			s.Close()
 
 		case mode&os.ModeDevice != 0:
 			if unshare.IsRootless() {

drivers/copy/copy_test.go

@@ -5,6 +5,7 @@ package copy
 import (
 	"fmt"
 	"math/rand"
+	"net"
 	"os"
 	"path/filepath"
 	"syscall"
@@ -83,6 +84,9 @@ func randomMode(baseMode int) os.FileMode {
 
 func populateSrcDir(t *testing.T, srcDir string, remainingDepth int) {
 	if remainingDepth == 0 {
+		socketName := filepath.Join(srcDir, fmt.Sprintf("srcsocket", i))
+		_, err := net.Listen("unix", socketName)
+		assert.NoError(t, err)
 		return
 	}
 	aTime := time.Unix(rand.Int63(), 0)