Driver should check socket parent directory before trying to bind it

Author: zhucan

pkg/gce-pd-csi-driver/server.go

@@ -87,19 +87,22 @@ func (s *nonBlockingGRPCServer) serve(endpoint string, ids csi.IdentityServer, c
 		if err := os.Remove(addr); err != nil && !os.IsNotExist(err) {
 			klog.Fatalf("Failed to remove %s, error: %s", addr, err.Error())
 		}
+
+		listenDir := filepath.Dir(addr)
+		if _, err := os.Stat(listenDir); err != nil {
+			if os.IsNotExist(err) {
+				klog.Fatalf("Expected Kubelet plugin watcher to create parent dir %s but did not find such a dir", listenDir)
+			} else {
+				klog.Fatalf("Failed to stat %s, error: %s", listenDir, err.Error())
+			}
+		}
+
 	} else if u.Scheme == "tcp" {
 		addr = u.Host
 	} else {
 		klog.Fatalf("%v endpoint scheme not supported", u.Scheme)
 	}
 
-	if u.Scheme == "unix" {
-		listenDir, _ := filepath.Split(addr)
-		if _, err := os.Stat(listenDir); err != nil {
-			klog.Fatalf("Failed to stat %s, error: %s", listenDir, err.Error())
-		}
-	}
-
 	klog.V(4).Infof("Start listening with scheme %v, addr %v", u.Scheme, addr)
 	listener, err := net.Listen(u.Scheme, addr)
 	if err != nil {