CephFS: Add subdir Option for Changing Mounted Root Directory

examples/cephfs/README.md

@@ -45,6 +45,7 @@ Then get the keyring from the Ceph cluster and copy it to */etc/ceph/keyring*.
 Once you have installed Ceph and a Kubernetes cluster, you can create a pod based on my examples [cephfs.yaml](cephfs.yaml)  and [cephfs-with-secret.yaml](cephfs-with-secret.yaml). In the pod yaml, you need to provide the following information.
 
 - *monitors*:  Array of Ceph monitors.
+- *path*: Used as the mounted root, rather than the full Ceph tree. If not provided, default */* is used.
 - *user*: The RADOS user name. If not provided, default *admin* is used.
 - *secretFile*: The path to the keyring file. If not provided, default */etc/ceph/user.secret* is used.
 - *secretRef*: Reference to Ceph authentication secrets. If provided, *secret* overrides *secretFile*.

pkg/api/types.go

@@ -637,6 +637,8 @@ type CinderVolumeSource struct {
 type CephFSVolumeSource struct {
 	// Required: Monitors is a collection of Ceph monitors
 	Monitors []string `json:"monitors"`
+	// Optional: Used as the mounted root, rather than the full Ceph tree, default is /
+	Path string `json:"path,omitempty"`
 	// Optional: User is the rados user name, default is admin
 	User string `json:"user,omitempty"`
 	// Optional: SecretFile is the path to key ring for User, default is /etc/ceph/user.secret

pkg/api/v1/types.go

@@ -590,6 +590,8 @@ type CephFSVolumeSource struct {
 	// Required: Monitors is a collection of Ceph monitors
 	// More info: http://releases.k8s.io/HEAD/examples/cephfs/README.md#how-to-use-it
 	Monitors []string `json:"monitors"`
+	// Optional: Used as the mounted root, rather than the full Ceph tree, default is /
+	Path string `json:"path,omitempty"`
 	// Optional: User is the rados user name, default is admin
 	// More info: http://releases.k8s.io/HEAD/examples/cephfs/README.md#how-to-use-it
 	User string `json:"user,omitempty"`

pkg/volume/cephfs/cephfs.go

@@ -19,12 +19,13 @@ package cephfs
 import (
 	"fmt"
 	"os"
+	"strings"
 
 	"github.com/golang/glog"
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/types"
 	"k8s.io/kubernetes/pkg/util/mount"
-	"k8s.io/kubernetes/pkg/util/strings"
+	utilstrings "k8s.io/kubernetes/pkg/util/strings"
 	"k8s.io/kubernetes/pkg/volume"
 )
 
@@ -92,6 +93,13 @@ func (plugin *cephfsPlugin) newBuilderInternal(spec *volume.Spec, podUID types.U
 	if id == "" {
 		id = "admin"
 	}
+	path := cephvs.Path
+	if path == "" {
+		path = "/"
+	}
+	if !strings.HasPrefix(path, "/") {
+		path = "/" + path
+	}
 	secret_file := cephvs.SecretFile
 	if secret_file == "" {
 		secret_file = "/etc/ceph/" + id + ".secret"
@@ -102,6 +110,7 @@ func (plugin *cephfsPlugin) newBuilderInternal(spec *volume.Spec, podUID types.U
 			podUID:      podUID,
 			volName:     spec.Name(),
 			mon:         cephvs.Monitors,
+			path:        path,
 			secret:      secret,
 			id:          id,
 			secret_file: secret_file,
@@ -138,6 +147,7 @@ type cephfs struct {
 	volName     string
 	podUID      types.UID
 	mon         []string
+	path        string
 	id          string
 	secret      string
 	secret_file string
@@ -208,7 +218,7 @@ func (cephfsVolume *cephfsCleaner) TearDownAt(dir string) error {
 // GatePath creates global mount path
 func (cephfsVolume *cephfs) GetPath() string {
 	name := cephfsPluginName
-	return cephfsVolume.plugin.host.GetPodVolumeDir(cephfsVolume.podUID, strings.EscapeQualifiedNameForDisk(name), cephfsVolume.volName)
+	return cephfsVolume.plugin.host.GetPodVolumeDir(cephfsVolume.podUID, utilstrings.EscapeQualifiedNameForDisk(name), cephfsVolume.volName)
 }
 
 func (cephfsVolume *cephfs) cleanup(dir string) error {
@@ -261,7 +271,7 @@ func (cephfsVolume *cephfs) execMount(mountpoint string) error {
 	for i = 0; i < l-1; i++ {
 		src += hosts[i] + ","
 	}
-	src += hosts[i] + ":/"
+	src += hosts[i] + ":" + cephfsVolume.path
 
 	if err := cephfsVolume.mounter.Mount(src, mountpoint, "ceph", opt); err != nil {
 		return fmt.Errorf("CephFS: mount failed: %v", err)