-
Notifications
You must be signed in to change notification settings - Fork 39.2k
/
gce_pd.go
283 lines (249 loc) · 8.49 KB
/
gce_pd.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
/*
Copyright 2014 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 gce_pd
import (
"fmt"
"os"
"path"
"strconv"
"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/volume"
"github.com/GoogleCloudPlatform/kubernetes/pkg/types"
"github.com/GoogleCloudPlatform/kubernetes/pkg/util/exec"
"github.com/GoogleCloudPlatform/kubernetes/pkg/util/mount"
"github.com/golang/glog"
)
// This is the primary entrypoint for volume plugins.
func ProbeVolumePlugins() []volume.Plugin {
return []volume.Plugin{&gcePersistentDiskPlugin{nil, false}, &gcePersistentDiskPlugin{nil, true}}
}
type gcePersistentDiskPlugin struct {
host volume.Host
legacyMode bool // if set, plugin answers to the legacy name
}
var _ volume.Plugin = &gcePersistentDiskPlugin{}
const (
gcePersistentDiskPluginName = "kubernetes.io/gce-pd"
gcePersistentDiskPluginLegacyName = "gce-pd"
)
func (plugin *gcePersistentDiskPlugin) Init(host volume.Host) {
plugin.host = host
}
func (plugin *gcePersistentDiskPlugin) Name() string {
if plugin.legacyMode {
return gcePersistentDiskPluginLegacyName
}
return gcePersistentDiskPluginName
}
func (plugin *gcePersistentDiskPlugin) CanSupport(spec *api.Volume) bool {
if plugin.legacyMode {
// Legacy mode instances can be cleaned up but not created anew.
return false
}
if spec.GCEPersistentDisk != nil {
return true
}
return false
}
func (plugin *gcePersistentDiskPlugin) NewBuilder(spec *api.Volume, podRef *api.ObjectReference) (volume.Builder, error) {
// Inject real implementations here, test through the internal function.
return plugin.newBuilderInternal(spec, podRef.UID, &GCEDiskUtil{}, mount.New())
}
func (plugin *gcePersistentDiskPlugin) newBuilderInternal(spec *api.Volume, podUID types.UID, manager pdManager, mounter mount.Interface) (volume.Builder, error) {
if plugin.legacyMode {
// Legacy mode instances can be cleaned up but not created anew.
return nil, fmt.Errorf("legacy mode: can not create new instances")
}
pdName := spec.GCEPersistentDisk.PDName
fsType := spec.GCEPersistentDisk.FSType
partition := ""
if spec.GCEPersistentDisk.Partition != 0 {
partition = strconv.Itoa(spec.GCEPersistentDisk.Partition)
}
readOnly := spec.GCEPersistentDisk.ReadOnly
return &gcePersistentDisk{
podUID: podUID,
volName: spec.Name,
pdName: pdName,
fsType: fsType,
partition: partition,
readOnly: readOnly,
manager: manager,
mounter: mounter,
diskMounter: &gceSafeFormatAndMount{mounter, exec.New()},
plugin: plugin,
legacyMode: false,
}, nil
}
func (plugin *gcePersistentDiskPlugin) NewCleaner(volName string, podUID types.UID) (volume.Cleaner, error) {
// Inject real implementations here, test through the internal function.
return plugin.newCleanerInternal(volName, podUID, &GCEDiskUtil{}, mount.New())
}
func (plugin *gcePersistentDiskPlugin) newCleanerInternal(volName string, podUID types.UID, manager pdManager, mounter mount.Interface) (volume.Cleaner, error) {
legacy := false
if plugin.legacyMode {
legacy = true
}
return &gcePersistentDisk{
podUID: podUID,
volName: volName,
manager: manager,
mounter: mounter,
diskMounter: &gceSafeFormatAndMount{mounter, exec.New()},
plugin: plugin,
legacyMode: legacy,
}, nil
}
// Abstract interface to PD operations.
type pdManager interface {
// Attaches the disk to the kubelet's host machine.
AttachAndMountDisk(pd *gcePersistentDisk, globalPDPath string) error
// Detaches the disk from the kubelet's host machine.
DetachDisk(pd *gcePersistentDisk) error
}
// gcePersistentDisk volumes are disk resources provided by Google Compute Engine
// that are attached to the kubelet's host machine and exposed to the pod.
type gcePersistentDisk struct {
volName string
podUID types.UID
// Unique identifier of the PD, used to find the disk resource in the provider.
pdName string
// Filesystem type, optional.
fsType string
// Specifies the partition to mount
partition string
// Specifies whether the disk will be attached as read-only.
readOnly bool
// Utility interface that provides API calls to the provider to attach/detach disks.
manager pdManager
// Mounter interface that provides system calls to mount the global path to the pod local path.
mounter mount.Interface
// diskMounter provides the interface that is used to mount the actual block device.
diskMounter mount.Interface
plugin *gcePersistentDiskPlugin
legacyMode bool
}
func detachDiskLogError(pd *gcePersistentDisk) {
err := pd.manager.DetachDisk(pd)
if err != nil {
glog.Warningf("Failed to detach disk: %v (%v)", pd, err)
}
}
// SetUp attaches the disk and bind mounts to the volume path.
func (pd *gcePersistentDisk) SetUp() error {
if pd.legacyMode {
return fmt.Errorf("legacy mode: can not create new instances")
}
// TODO: handle failed mounts here.
mountpoint, err := mount.IsMountPoint(pd.GetPath())
glog.V(4).Infof("PersistentDisk set up: %s %v %v", pd.GetPath(), mountpoint, err)
if err != nil && !os.IsNotExist(err) {
return err
}
if mountpoint {
return nil
}
globalPDPath := makeGlobalPDName(pd.plugin.host, pd.pdName)
if err := pd.manager.AttachAndMountDisk(pd, globalPDPath); err != nil {
return err
}
flags := uintptr(0)
if pd.readOnly {
flags = mount.FlagReadOnly
}
volPath := pd.GetPath()
if err := os.MkdirAll(volPath, 0750); err != nil {
// TODO: we should really eject the attach/detach out into its own control loop.
detachDiskLogError(pd)
return err
}
// Perform a bind mount to the full path to allow duplicate mounts of the same PD.
err = pd.mounter.Mount(globalPDPath, pd.GetPath(), "", mount.FlagBind|flags, "")
if err != nil {
mountpoint, mntErr := mount.IsMountPoint(pd.GetPath())
if mntErr != nil {
glog.Errorf("isMountpoint check failed: %v", mntErr)
return err
}
if mountpoint {
if mntErr = pd.mounter.Unmount(pd.GetPath(), 0); mntErr != nil {
glog.Errorf("Failed to unmount: %v", mntErr)
return err
}
mountpoint, mntErr := mount.IsMountPoint(pd.GetPath())
if mntErr != nil {
glog.Errorf("isMountpoint check failed: %v", mntErr)
return err
}
if mountpoint {
// This is very odd, we don't expect it. We'll try again next sync loop.
glog.Errorf("%s is still mounted, despite call to unmount(). Will try again next sync loop.", pd.GetPath())
return err
}
}
os.Remove(pd.GetPath())
// TODO: we should really eject the attach/detach out into its own control loop.
detachDiskLogError(pd)
return err
}
return nil
}
func makeGlobalPDName(host volume.Host, devName string) string {
return path.Join(host.GetPluginDir(gcePersistentDiskPluginName), "mounts", devName)
}
func (pd *gcePersistentDisk) GetPath() string {
name := gcePersistentDiskPluginName
if pd.legacyMode {
name = gcePersistentDiskPluginLegacyName
}
return pd.plugin.host.GetPodVolumeDir(pd.podUID, volume.EscapePluginName(name), pd.volName)
}
// Unmounts the bind mount, and detaches the disk only if the PD
// resource was the last reference to that disk on the kubelet.
func (pd *gcePersistentDisk) TearDown() error {
mountpoint, err := mount.IsMountPoint(pd.GetPath())
if err != nil {
return err
}
if !mountpoint {
return os.Remove(pd.GetPath())
}
refs, err := mount.GetMountRefs(pd.mounter, pd.GetPath())
if err != nil {
return err
}
// Unmount the bind-mount inside this pod
if err := pd.mounter.Unmount(pd.GetPath(), 0); err != nil {
return err
}
// If len(refs) is 1, then all bind mounts have been removed, and the
// remaining reference is the global mount. It is safe to detach.
if len(refs) == 1 {
// pd.pdName is not initially set for volume-cleaners, so set it here.
pd.pdName = path.Base(refs[0])
if err := pd.manager.DetachDisk(pd); err != nil {
return err
}
}
mountpoint, mntErr := mount.IsMountPoint(pd.GetPath())
if mntErr != nil {
glog.Errorf("isMountpoint check failed: %v", mntErr)
return err
}
if !mountpoint {
if err := os.Remove(pd.GetPath()); err != nil {
return err
}
}
return nil
}