-
Notifications
You must be signed in to change notification settings - Fork 19
/
base_image_puller.go
324 lines (263 loc) · 9.85 KB
/
base_image_puller.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
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
package base_image_puller // import "code.cloudfoundry.org/grootfs/base_image_puller"
import (
"fmt"
"io"
"math/rand"
"os"
"path"
"path/filepath"
"strings"
"syscall"
"time"
"code.cloudfoundry.org/grootfs/groot"
"code.cloudfoundry.org/lager"
errorspkg "github.com/pkg/errors"
)
const MetricsUnpackTimeName = "UnpackTime"
const MetricsDownloadTimeName = "DownloadTime"
//go:generate counterfeiter . Fetcher
//go:generate counterfeiter . Unpacker
//go:generate counterfeiter . DependencyRegisterer
//go:generate counterfeiter . VolumeDriver
type UnpackSpec struct {
Stream io.ReadCloser `json:"-"`
TargetPath string
UIDMappings []groot.IDMappingSpec
GIDMappings []groot.IDMappingSpec
BaseDirectory string
}
type VolumeMeta struct {
Size int64
}
type Fetcher interface {
BaseImageInfo(logger lager.Logger) (groot.BaseImageInfo, error)
StreamBlob(logger lager.Logger, layerInfo groot.LayerInfo) (io.ReadCloser, int64, error)
Close() error
}
type DependencyRegisterer interface {
Register(id string, chainIDs []string) error
}
type UnpackOutput struct {
BytesWritten int64
OpaqueWhiteouts []string
}
type Unpacker interface {
Unpack(logger lager.Logger, spec UnpackSpec) (UnpackOutput, error)
}
type VolumeDriver interface {
VolumePath(logger lager.Logger, id string) (string, error)
CreateVolume(logger lager.Logger, parentID, id string) (string, error)
DestroyVolume(logger lager.Logger, id string) error
Volumes(logger lager.Logger) ([]string, error)
MoveVolume(logger lager.Logger, from, to string) error
WriteVolumeMeta(logger lager.Logger, id string, data VolumeMeta) error
HandleOpaqueWhiteouts(logger lager.Logger, id string, opaqueWhiteouts []string) error
}
type BaseImagePuller struct {
fetcher Fetcher
unpacker Unpacker
volumeDriver VolumeDriver
metricsEmitter groot.MetricsEmitter
locksmith groot.Locksmith
}
func NewBaseImagePuller(fetcher Fetcher, unpacker Unpacker, volumeDriver VolumeDriver, metricsEmitter groot.MetricsEmitter, locksmith groot.Locksmith) *BaseImagePuller {
return &BaseImagePuller{
fetcher: fetcher,
unpacker: unpacker,
volumeDriver: volumeDriver,
metricsEmitter: metricsEmitter,
locksmith: locksmith,
}
}
func (p *BaseImagePuller) FetchBaseImageInfo(logger lager.Logger) (groot.BaseImageInfo, error) {
logger = logger.Session("fetching-image-info")
logger.Info("starting")
defer logger.Info("ending")
return p.fetcher.BaseImageInfo(logger)
}
func (p *BaseImagePuller) Pull(logger lager.Logger, baseImageInfo groot.BaseImageInfo, spec groot.BaseImageSpec) error {
logger = logger.Session("pulling-image-layers", lager.Data{"spec": spec})
logger.Info("starting")
defer logger.Info("ending")
if err := p.quotaExceeded(logger, baseImageInfo.LayerInfos, spec); err != nil {
return err
}
return p.buildLayer(logger, len(baseImageInfo.LayerInfos)-1, baseImageInfo.LayerInfos, spec)
}
func (p *BaseImagePuller) quotaExceeded(logger lager.Logger, layerInfos []groot.LayerInfo, spec groot.BaseImageSpec) error {
if spec.ExcludeBaseImageFromQuota || spec.DiskLimit == 0 {
return nil
}
totalSize := p.layersSize(layerInfos)
if totalSize > spec.DiskLimit {
err := errorspkg.Errorf("layers exceed disk quota %d/%d bytes", totalSize, spec.DiskLimit)
logger.Error("blob-manifest-size-check-failed", err, lager.Data{
"totalSize": totalSize,
"diskLimit": spec.DiskLimit,
"excludeBaseImageFromQuota": spec.ExcludeBaseImageFromQuota,
})
return err
}
return nil
}
func (p *BaseImagePuller) volumeExists(logger lager.Logger, chainID string) bool {
volumePath, err := p.volumeDriver.VolumePath(logger, chainID)
if err == nil {
logger.Debug("volume-exists", lager.Data{
"volumePath": volumePath,
})
return true
}
return false
}
func (p *BaseImagePuller) buildLayer(logger lager.Logger, index int, layerInfos []groot.LayerInfo, spec groot.BaseImageSpec) error {
if index < 0 {
return nil
}
layerInfo := layerInfos[index]
logger = logger.Session("build-layer", lager.Data{
"blobID": layerInfo.BlobID,
"chainID": layerInfo.ChainID,
"parentChainID": layerInfo.ParentChainID,
})
if p.volumeExists(logger, layerInfo.ChainID) {
return nil
}
lockFile, err := p.locksmith.Lock(layerInfo.ChainID)
if err != nil {
return errorspkg.Wrap(err, "acquiring lock")
}
defer p.locksmith.Unlock(lockFile)
if p.volumeExists(logger, layerInfo.ChainID) {
return nil
}
if err := p.buildLayer(logger, index-1, layerInfos, spec); err != nil {
return err
}
var parentLayerInfo groot.LayerInfo
if index > 0 {
parentLayerInfo = layerInfos[index-1]
}
return p.downloadLayer(logger, layerInfo, parentLayerInfo, spec)
}
func (p *BaseImagePuller) downloadLayer(logger lager.Logger, layerInfo, parentLayerInfo groot.LayerInfo, spec groot.BaseImageSpec) error {
logger = logger.Session("downloading-layer", lager.Data{"LayerInfo": layerInfo})
logger.Debug("starting")
defer logger.Debug("ending")
defer p.metricsEmitter.TryEmitDurationFrom(logger, MetricsDownloadTimeName, time.Now())
stream, size, err := p.fetcher.StreamBlob(logger, layerInfo)
if err != nil {
return errorspkg.Wrapf(err, "streaming blob `%s`", layerInfo.BlobID)
}
defer stream.Close()
logger.Debug("got-stream-for-blob", lager.Data{"size": size})
return p.unpackLayer(logger, layerInfo, parentLayerInfo, spec, stream)
}
func (p *BaseImagePuller) unpackLayer(logger lager.Logger, layerInfo, parentLayerInfo groot.LayerInfo, spec groot.BaseImageSpec, stream io.ReadCloser) error {
logger = logger.Session("unpacking-layer", lager.Data{"LayerInfo": layerInfo})
logger.Debug("starting")
defer logger.Debug("ending")
tempVolumeName, volumePath, err := p.createTemporaryVolumeDirectory(logger, layerInfo, spec)
if err != nil {
return err
}
unpackSpec := UnpackSpec{
TargetPath: volumePath,
Stream: stream,
UIDMappings: spec.UIDMappings,
GIDMappings: spec.GIDMappings,
BaseDirectory: layerInfo.BaseDirectory,
}
volSize, err := p.unpackLayerToTemporaryDirectory(logger, unpackSpec, layerInfo, parentLayerInfo)
if err != nil {
return err
}
return p.finalizeVolume(logger, tempVolumeName, volumePath, layerInfo.ChainID, volSize)
}
func (p *BaseImagePuller) createTemporaryVolumeDirectory(logger lager.Logger, layerInfo groot.LayerInfo, spec groot.BaseImageSpec) (string, string, error) {
tempVolumeName := fmt.Sprintf("%s-incomplete-%d-%d", layerInfo.ChainID, time.Now().UnixNano(), rand.Int())
volumePath, err := p.volumeDriver.CreateVolume(logger,
layerInfo.ParentChainID,
tempVolumeName,
)
if err != nil {
return "", "", errorspkg.Wrapf(err, "creating volume for layer `%s`", layerInfo.BlobID)
}
logger.Debug("volume-created", lager.Data{"volumePath": volumePath})
if spec.OwnerUID != 0 || spec.OwnerGID != 0 {
err = os.Chown(volumePath, spec.OwnerUID, spec.OwnerGID)
if err != nil {
return "", "", errorspkg.Wrapf(err, "changing volume ownership to %d:%d", spec.OwnerUID, spec.OwnerGID)
}
}
return tempVolumeName, volumePath, nil
}
func (p *BaseImagePuller) unpackLayerToTemporaryDirectory(logger lager.Logger, unpackSpec UnpackSpec, layerInfo, parentLayerInfo groot.LayerInfo) (volSize int64, err error) {
defer p.metricsEmitter.TryEmitDurationFrom(logger, MetricsUnpackTimeName, time.Now())
if unpackSpec.BaseDirectory != "" {
parentPath, err := p.volumeDriver.VolumePath(logger, parentLayerInfo.ChainID)
if err != nil {
return 0, err
}
if err := ensureBaseDirectoryExists(unpackSpec.BaseDirectory, unpackSpec.TargetPath, parentPath); err != nil {
return 0, err
}
}
var unpackOutput UnpackOutput
if unpackOutput, err = p.unpacker.Unpack(logger, unpackSpec); err != nil {
if errD := p.volumeDriver.DestroyVolume(logger, layerInfo.ChainID); errD != nil {
logger.Error("volume-cleanup-failed", errD)
}
return 0, errorspkg.Wrapf(err, "unpacking layer `%s`", layerInfo.BlobID)
}
if err := p.volumeDriver.HandleOpaqueWhiteouts(logger, path.Base(unpackSpec.TargetPath), unpackOutput.OpaqueWhiteouts); err != nil {
logger.Error("handling-opaque-whiteouts", err)
return 0, errorspkg.Wrap(err, "handling opaque whiteouts")
}
logger.Debug("layer-unpacked")
return unpackOutput.BytesWritten, nil
}
func (p *BaseImagePuller) finalizeVolume(logger lager.Logger, tempVolumeName, volumePath, chainID string, volSize int64) error {
if err := p.volumeDriver.WriteVolumeMeta(logger, chainID, VolumeMeta{Size: volSize}); err != nil {
return errorspkg.Wrapf(err, "writing volume `%s` metadata", chainID)
}
finalVolumePath := strings.Replace(volumePath, tempVolumeName, chainID, 1)
if err := p.volumeDriver.MoveVolume(logger, volumePath, finalVolumePath); err != nil {
return errorspkg.Wrapf(err, "failed to move volume to its final location")
}
return nil
}
func (p *BaseImagePuller) layersSize(layerInfos []groot.LayerInfo) int64 {
var totalSize int64
for _, layerInfo := range layerInfos {
totalSize += layerInfo.Size
}
return totalSize
}
func ensureBaseDirectoryExists(baseDir, childPath, parentPath string) error {
if baseDir == string(filepath.Separator) {
return nil
}
if err := ensureBaseDirectoryExists(filepath.Dir(baseDir), childPath, parentPath); err != nil {
return err
}
stat, err := os.Stat(filepath.Join(childPath, baseDir))
if err == nil {
return nil
} else if !os.IsNotExist(err) {
return errorspkg.Wrapf(err, "failed to stat base directory")
}
stat, err = os.Stat(filepath.Join(parentPath, baseDir))
if err != nil {
return errorspkg.Wrapf(err, "base directory not found in parent layer")
}
fullChildBaseDir := filepath.Join(childPath, baseDir)
if err := os.Mkdir(fullChildBaseDir, stat.Mode()); err != nil {
return errorspkg.Wrapf(err, "could not create base directory in child layer")
}
stat_t := stat.Sys().(*syscall.Stat_t)
if err := os.Chown(fullChildBaseDir, int(stat_t.Uid), int(stat_t.Gid)); err != nil {
return errorspkg.Wrapf(err, "could not chown base directory")
}
return nil
}