Recycling HostPath and NFS impls

pkg/volume/host_path/host_path.go

@@ -18,23 +18,35 @@ package host_path
 
 import (
 	"fmt"
+	"time"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/types"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util/mount"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/volume"
 )
 
 // This is the primary entrypoint for volume plugins.
+// Tests covering recycling should not use this func but instead
+// use their own array of plugins w/ a custom recyclerFunc as appropriate
 func ProbeVolumePlugins() []volume.VolumePlugin {
-	return []volume.VolumePlugin{&hostPathPlugin{nil}}
+	return []volume.VolumePlugin{&hostPathPlugin{nil, newRecycler}}
+}
+
+func ProbeRecyclableVolumePlugins(recyclerFunc func(spec *volume.Spec, host volume.VolumeHost) (volume.Recycler, error)) []volume.VolumePlugin {
+	return []volume.VolumePlugin{&hostPathPlugin{nil, recyclerFunc}}
 }
 
 type hostPathPlugin struct {
 	host volume.VolumeHost
+	// decouple creating recyclers by deferring to a function.  Allows for easier testing.
+	newRecyclerFunc func(spec *volume.Spec, host volume.VolumeHost) (volume.Recycler, error)
 }
 
 var _ volume.VolumePlugin = &hostPathPlugin{}
+var _ volume.PersistentVolumePlugin = &hostPathPlugin{}
+var _ volume.RecyclableVolumePlugin = &hostPathPlugin{}
 
 const (
 	hostPathPluginName = "kubernetes.io/host-path"
@@ -70,6 +82,18 @@ func (plugin *hostPathPlugin) NewCleaner(volName string, podUID types.UID, _ mou
 	return &hostPath{""}, nil
 }
 
+func (plugin *hostPathPlugin) NewRecycler(spec *volume.Spec) (volume.Recycler, error) {
+	return plugin.newRecyclerFunc(spec, plugin.host)
+}
+
+func newRecycler(spec *volume.Spec, host volume.VolumeHost) (volume.Recycler, error) {
+	if spec.VolumeSource.HostPath != nil {
+		return &hostPathRecycler{spec.Name, spec.VolumeSource.HostPath.Path, host}, nil
+	} else {
+		return &hostPathRecycler{spec.Name, spec.PersistentVolumeSource.HostPath.Path, host}, nil
+	}
+}
+
 // HostPath volumes represent a bare host file or directory mount.
 // The direct at the specified path will be directly exposed to the container.
 type hostPath struct {
@@ -99,3 +123,64 @@ func (hp *hostPath) TearDown() error {
 func (hp *hostPath) TearDownAt(dir string) error {
 	return fmt.Errorf("TearDownAt() does not make sense for host paths")
 }
+
+// hostPathRecycler scrubs a hostPath volume by running "rm -rf" on the volume in a pod
+// This recycler only works on a single host cluster and is for testing purposes only.
+type hostPathRecycler struct {
+	name string
+	path string
+	host volume.VolumeHost
+}
+
+func (r *hostPathRecycler) GetPath() string {
+	return r.path
+}
+
+// Recycler provides methods to reclaim the volume resource.
+// A HostPath is recycled by scheduling a pod to run "rm -rf" on the contents of the volume.  This is meant for
+// development and testing in a single node cluster only.
+// Recycle blocks until the pod has completed or any error occurs.
+// The scrubber pod's is expected to succeed within 30 seconds when testing localhost.
+func (r *hostPathRecycler) Recycle() error {
+	timeout := int64(30 * time.Second)
+	pod := &api.Pod{
+		ObjectMeta: api.ObjectMeta{
+			GenerateName: "pv-scrubber-" + util.ShortenString(r.name, 44) + "-",
+			Namespace:    api.NamespaceDefault,
+		},
+		Spec: api.PodSpec{
+			ActiveDeadlineSeconds: &timeout,
+			RestartPolicy:         api.RestartPolicyNever,
+			Volumes: []api.Volume{
+				{
+					Name: "vol",
+					VolumeSource: api.VolumeSource{
+						HostPath: &api.HostPathVolumeSource{r.path},
+					},
+				},
+			},
+			Containers: []api.Container{
+				{
+					Name:  "scrubber",
+					Image: "busybox",
+					// delete the contents of the volume, but not the directory itself
+					Command: []string{"/bin/sh"},
+					// the scrubber:
+					//		1. validates the /scrub directory exists
+					// 		2. creates a text file in the directory to be scrubbed
+					//		3. performs rm -rf on the directory
+					//		4. tests to see if the directory is empty
+					// the pod fails if the error code is returned
+					Args: []string{"-c", "test -e /scrub && echo $(date) > /scrub/trash.txt && rm -rf /scrub/* && test -z \"$(ls -A /scrub)\" || exit 1"},
+					VolumeMounts: []api.VolumeMount{
+						{
+							Name:      "vol",
+							MountPath: "/scrub",
+						},
+					},
+				},
+			},
+		},
+	}
+	return volume.ScrubPodVolumeAndWatchUntilCompletion(pod, r.host.GetKubeClient())
+}