Update go dependencies

vendor/k8s.io/utils/path/file.go

@@ -0,0 +1,78 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package path
+
+import (
+	"errors"
+	"os"
+)
+
+// LinkTreatment is the base type for constants used by Exists that indicate
+// how symlinks are treated for existence checks.
+type LinkTreatment int
+
+const (
+	// CheckFollowSymlink follows the symlink and verifies that the target of
+	// the symlink exists.
+	CheckFollowSymlink LinkTreatment = iota
+
+	// CheckSymlinkOnly does not follow the symlink and verfies only that they
+	// symlink itself exists.
+	CheckSymlinkOnly
+)
+
+// ErrInvalidLinkTreatment indicates that the link treatment behavior requested
+// is not a valid behavior.
+var ErrInvalidLinkTreatment = errors.New("unknown link behavior")
+
+// Exists checks if specified file, directory, or symlink exists. The behavior
+// of the test depends on the linkBehaviour argument. See LinkTreatment for
+// more details.
+func Exists(linkBehavior LinkTreatment, filename string) (bool, error) {
+	var err error
+
+	if linkBehavior == CheckFollowSymlink {
+		_, err = os.Stat(filename)
+	} else if linkBehavior == CheckSymlinkOnly {
+		_, err = os.Lstat(filename)
+	} else {
+		return false, ErrInvalidLinkTreatment
+	}
+
+	if os.IsNotExist(err) {
+		return false, nil
+	} else if err != nil {
+		return false, err
+	}
+	return true, nil
+}
+
+// ReadDirNoStat returns a string of files/directories contained
+// in dirname without calling lstat on them.
+func ReadDirNoStat(dirname string) ([]string, error) {
+	if dirname == "" {
+		dirname = "."
+	}
+
+	f, err := os.Open(dirname)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	return f.Readdirnames(-1)
+}