Fix cross-compliation of mount_exec.go

Add dummy implementation for non-linux platforms

pkg/util/mount/BUILD

@@ -11,6 +11,7 @@ go_library(
     srcs = [
         "doc.go",
         "exec.go",
+        "exec_mount_unsupported.go",
         "fake.go",
         "mount.go",
         "mount_unsupported.go",

pkg/util/mount/exec_mount_unsupported.go

@@ -0,0 +1,87 @@
+// +build !linux
+
+/*
+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 mount
+
+import (
+	"errors"
+)
+
+type execMounter struct{}
+
+// ExecMounter is a mounter that uses provided Exec interface to mount and
+// unmount a filesystem. For all other calls it uses a wrapped mounter.
+func NewExecMounter(exec Exec, wrapped Interface) Interface {
+	return &execMounter{}
+}
+
+func (mounter *execMounter) Mount(source string, target string, fstype string, options []string) error {
+	return nil
+}
+
+func (mounter *execMounter) Unmount(target string) error {
+	return nil
+}
+
+func (mounter *execMounter) List() ([]MountPoint, error) {
+	return []MountPoint{}, nil
+}
+
+func (mounter *execMounter) IsMountPointMatch(mp MountPoint, dir string) bool {
+	return (mp.Path == dir)
+}
+
+func (mounter *execMounter) IsNotMountPoint(dir string) (bool, error) {
+	return IsNotMountPoint(mounter, dir)
+}
+
+func (mounter *execMounter) IsLikelyNotMountPoint(file string) (bool, error) {
+	return true, nil
+}
+
+func (mounter *execMounter) GetDeviceNameFromMount(mountPath, pluginDir string) (string, error) {
+	return "", nil
+}
+
+func (mounter *execMounter) DeviceOpened(pathname string) (bool, error) {
+	return false, nil
+}
+
+func (mounter *execMounter) PathIsDevice(pathname string) (bool, error) {
+	return true, nil
+}
+
+func (mounter *execMounter) MakeRShared(path string) error {
+	return nil
+}
+
+func (mounter *execMounter) GetFileType(pathname string) (FileType, error) {
+	return FileType("fake"), errors.New("not implemented")
+}
+
+func (mounter *execMounter) MakeDir(pathname string) error {
+	return nil
+}
+
+func (mounter *execMounter) MakeFile(pathname string) error {
+	return nil
+}
+
+func (mounter *execMounter) ExistsPath(pathname string) bool {
+	return true
+}