Make secret volume plugin idempotent

pkg/volume/git_repo/git_repo.go

@@ -19,7 +19,6 @@ package git_repo
 import (
 	"fmt"
 	"io/ioutil"
-	"os"
 	"path"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
@@ -27,7 +26,7 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util/exec"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/volume"
-	"github.com/golang/glog"
+	volumeutil "github.com/GoogleCloudPlatform/kubernetes/pkg/volume/util"
 )
 
 // This is the primary entrypoint for volume plugins.
@@ -123,7 +122,7 @@ var wrappedVolumeSpec = &volume.Spec{
 
 // SetUpAt creates new directory and clones a git repo.
 func (gr *gitRepo) SetUpAt(dir string) error {
-	if gr.isReady() {
+	if volumeutil.IsReady(gr.getMetaDir()) {
 		return nil
 	}
 	if gr.legacyMode {
@@ -152,7 +151,7 @@ func (gr *gitRepo) SetUpAt(dir string) error {
 	}
 	if len(gr.revision) == 0 {
 		// Done!
-		gr.setReady()
+		volumeutil.SetReady(gr.getMetaDir())
 		return nil
 	}
 
@@ -164,7 +163,7 @@ func (gr *gitRepo) SetUpAt(dir string) error {
 		return fmt.Errorf("failed to exec 'git reset --hard': %s: %v", output, err)
 	}
 
-	gr.setReady()
+	volumeutil.SetReady(gr.getMetaDir())
 	return nil
 }
 
@@ -172,35 +171,6 @@ func (gr *gitRepo) getMetaDir() string {
 	return path.Join(gr.plugin.host.GetPodPluginDir(gr.podRef.UID, util.EscapeQualifiedNameForDisk(gitRepoPluginName)), gr.volName)
 }
 
-func (gr *gitRepo) isReady() bool {
-	metaDir := gr.getMetaDir()
-	readyFile := path.Join(metaDir, "ready")
-	s, err := os.Stat(readyFile)
-	if err != nil {
-		return false
-	}
-	if !s.Mode().IsRegular() {
-		glog.Errorf("GitRepo ready-file is not a file: %s", readyFile)
-		return false
-	}
-	return true
-}
-
-func (gr *gitRepo) setReady() {
-	metaDir := gr.getMetaDir()
-	if err := os.MkdirAll(metaDir, 0750); err != nil && !os.IsExist(err) {
-		glog.Errorf("Can't mkdir %s: %v", metaDir, err)
-		return
-	}
-	readyFile := path.Join(metaDir, "ready")
-	file, err := os.Create(readyFile)
-	if err != nil {
-		glog.Errorf("Can't touch %s: %v", readyFile, err)
-		return
-	}
-	file.Close()
-}
-
 func (gr *gitRepo) execCommand(command string, args []string, dir string) ([]byte, error) {
 	cmd := gr.exec.Command(command, args...)
 	cmd.SetDir(dir)

pkg/volume/secret/secret.go

@@ -25,6 +25,7 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/types"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/volume"
+	volumeutil "github.com/GoogleCloudPlatform/kubernetes/pkg/volume/util"
 	"github.com/golang/glog"
 )
 
@@ -91,6 +92,10 @@ var wrappedVolumeSpec = &volume.Spec{
 }
 
 func (sv *secretVolume) SetUpAt(dir string) error {
+	if volumeutil.IsReady(sv.getMetaDir()) {
+		return nil
+	}
+
 	glog.V(3).Infof("Setting up volume %v for pod %v at %v", sv.volName, sv.podRef.UID, dir)
 
 	// Wrap EmptyDir, let it do the setup.
@@ -130,6 +135,8 @@ func (sv *secretVolume) SetUpAt(dir string) error {
 		}
 	}
 
+	volumeutil.SetReady(sv.getMetaDir())
+
 	return nil
 }
 
@@ -160,3 +167,7 @@ func (sv *secretVolume) TearDownAt(dir string) error {
 	}
 	return wrapped.TearDownAt(dir)
 }
+
+func (sv *secretVolume) getMetaDir() string {
+	return path.Join(sv.plugin.host.GetPodPluginDir(sv.podRef.UID, util.EscapeQualifiedNameForDisk(secretPluginName)), sv.volName)
+}

pkg/volume/util/doc.go

+/*
+Copyright 2015 Google Inc. All rights reserved.
+
+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.
+*/
+
+// Contains utility code for use by volume plugins.
+package util

pkg/volume/util/util.go

+/*
+Copyright 2015 Google Inc. All rights reserved.
+
+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 util
+
+import (
+	"os"
+	"path"
+
+	"github.com/golang/glog"
+)
+
+const readyFileName = "ready"
+
+// IsReady checks for the existence of a regular file
+// called 'ready' in the given directory and returns
+// true if that file exists.
+func IsReady(dir string) bool {
+	readyFile := path.Join(dir, readyFileName)
+	s, err := os.Stat(readyFile)
+	if err != nil {
+		return false
+	}
+
+	if !s.Mode().IsRegular() {
+		glog.Errorf("ready-file is not a file: %s", readyFile)
+		return false
+	}
+
+	return true
+}
+
+// SetReady creates a file called 'ready' in the given
+// directory.  It logs an error if the file cannot be
+// created.
+func SetReady(dir string) {
+	if err := os.MkdirAll(dir, 0750); err != nil && !os.IsExist(err) {
+		glog.Errorf("Can't mkdir %s: %v", dir, err)
+		return
+	}
+
+	readyFile := path.Join(dir, readyFileName)
+	file, err := os.Create(readyFile)
+	if err != nil {
+		glog.Errorf("Can't touch %s: %v", readyFile, err)
+		return
+	}
+	file.Close()
+}