aboutsummaryrefslogtreecommitdiff
path: root/libpod/image/image.go
blob: 80cc6f15a12dc1b55ea24a47e9fb9baf4346f71e (plain)
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
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
package image

import (
	"context"
	"encoding/json"
	stderrors "errors"
	"fmt"
	"io"
	"io/ioutil"
	"os"
	"path/filepath"
	"sort"
	"strings"
	"syscall"
	"time"

	cp "github.com/containers/image/v5/copy"
	"github.com/containers/image/v5/directory"
	dockerarchive "github.com/containers/image/v5/docker/archive"
	"github.com/containers/image/v5/docker/reference"
	"github.com/containers/image/v5/image"
	"github.com/containers/image/v5/manifest"
	ociarchive "github.com/containers/image/v5/oci/archive"
	is "github.com/containers/image/v5/storage"
	"github.com/containers/image/v5/tarball"
	"github.com/containers/image/v5/transports"
	"github.com/containers/image/v5/transports/alltransports"
	"github.com/containers/image/v5/types"
	"github.com/containers/libpod/libpod/driver"
	"github.com/containers/libpod/libpod/events"
	"github.com/containers/libpod/pkg/inspect"
	"github.com/containers/libpod/pkg/registries"
	"github.com/containers/libpod/pkg/util"
	"github.com/containers/storage"
	"github.com/opencontainers/go-digest"
	imgspecv1 "github.com/opencontainers/image-spec/specs-go/v1"
	ociv1 "github.com/opencontainers/image-spec/specs-go/v1"
	"github.com/opentracing/opentracing-go"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
)

// Image is the primary struct for dealing with images
// It is still very much a work in progress
type Image struct {
	// Adding these two structs for now but will cull when we near
	// completion of this library.
	imgRef    types.Image
	imgSrcRef types.ImageSource
	inspect.ImageData
	inspect.ImageResult
	inspectInfo  *types.ImageInspectInfo
	InputName    string
	image        *storage.Image
	imageruntime *Runtime
}

// Runtime contains the store
type Runtime struct {
	store               storage.Store
	SignaturePolicyPath string
	EventsLogFilePath   string
	EventsLogger        string
	Eventer             events.Eventer
}

// InfoImage keep information of Image along with all associated layers
type InfoImage struct {
	// ID of image
	ID string
	// Tags of image
	Tags []string
	// Layers stores all layers of image.
	Layers []LayerInfo
}

// ImageFilter is a function to determine whether a image is included
// in command output. Images to be outputted are tested using the function.
// A true return will include the image, a false return will exclude it.
type ImageFilter func(*Image) bool //nolint

// ErrRepoTagNotFound is the error returned when the image id given doesn't match a rep tag in store
var ErrRepoTagNotFound = stderrors.New("unable to match user input to any specific repotag")

// ErrImageIsBareList is the error returned when the image is just a list or index
var ErrImageIsBareList = stderrors.New("image contains a manifest list or image index, but no runnable image")

// NewImageRuntimeFromStore creates an ImageRuntime based on a provided store
func NewImageRuntimeFromStore(store storage.Store) *Runtime {
	return &Runtime{
		store: store,
	}
}

// NewImageRuntimeFromOptions creates an Image Runtime including the store given
// store options
func NewImageRuntimeFromOptions(options storage.StoreOptions) (*Runtime, error) {
	store, err := setStore(options)
	if err != nil {
		return nil, err
	}
	return NewImageRuntimeFromStore(store), nil
}

func setStore(options storage.StoreOptions) (storage.Store, error) {
	store, err := storage.GetStore(options)
	if err != nil {
		return nil, err
	}
	is.Transport.SetStore(store)
	return store, nil
}

// newImage creates a new image object given an "input name" and a storage.Image
func (ir *Runtime) newImage(inputName string, img *storage.Image) *Image {
	return &Image{
		InputName:    inputName,
		imageruntime: ir,
		image:        img,
	}
}

// newFromStorage creates a new image object from a storage.Image. Its "input name" will be its ID.
func (ir *Runtime) newFromStorage(img *storage.Image) *Image {
	return ir.newImage(img.ID, img)
}

// NewFromLocal creates a new image object that is intended
// to only deal with local images already in the store (or
// its aliases)
func (ir *Runtime) NewFromLocal(name string) (*Image, error) {
	updatedInputName, localImage, err := ir.getLocalImage(name)
	if err != nil {
		return nil, err
	}
	return ir.newImage(updatedInputName, localImage), nil
}

// New creates a new image object where the image could be local
// or remote
func (ir *Runtime) New(ctx context.Context, name, signaturePolicyPath, authfile string, writer io.Writer, dockeroptions *DockerRegistryOptions, signingoptions SigningOptions, label *string, pullType util.PullType) (*Image, error) {
	span, _ := opentracing.StartSpanFromContext(ctx, "newImage")
	span.SetTag("type", "runtime")
	defer span.Finish()

	// We don't know if the image is local or not ... check local first
	if pullType != util.PullImageAlways {
		newImage, err := ir.NewFromLocal(name)
		if err == nil {
			return newImage, nil
		} else if pullType == util.PullImageNever {
			return nil, err
		}
	}

	// The image is not local
	if signaturePolicyPath == "" {
		signaturePolicyPath = ir.SignaturePolicyPath
	}
	imageName, err := ir.pullImageFromHeuristicSource(ctx, name, writer, authfile, signaturePolicyPath, signingoptions, dockeroptions, label)
	if err != nil {
		return nil, errors.Wrapf(err, "unable to pull %s", name)
	}

	newImage, err := ir.NewFromLocal(imageName[0])
	if err != nil {
		return nil, errors.Wrapf(err, "error retrieving local image after pulling %s", name)
	}
	return newImage, nil
}

// LoadFromArchiveReference creates a new image object for images pulled from a tar archive and the like (podman load)
// This function is needed because it is possible for a tar archive to have multiple tags for one image
func (ir *Runtime) LoadFromArchiveReference(ctx context.Context, srcRef types.ImageReference, signaturePolicyPath string, writer io.Writer) ([]*Image, error) {
	var newImages []*Image

	if signaturePolicyPath == "" {
		signaturePolicyPath = ir.SignaturePolicyPath
	}
	imageNames, err := ir.pullImageFromReference(ctx, srcRef, writer, "", signaturePolicyPath, SigningOptions{}, &DockerRegistryOptions{})
	if err != nil {
		return nil, errors.Wrapf(err, "unable to pull %s", transports.ImageName(srcRef))
	}

	for _, name := range imageNames {
		newImage, err := ir.NewFromLocal(name)
		if err != nil {
			return nil, errors.Wrapf(err, "error retrieving local image after pulling %s", name)
		}
		newImages = append(newImages, newImage)
	}
	ir.newImageEvent(events.LoadFromArchive, "")
	return newImages, nil
}

// Shutdown closes down the storage and require a bool arg as to
// whether it should do so forcibly.
func (ir *Runtime) Shutdown(force bool) error {
	_, err := ir.store.Shutdown(force)
	return err
}

// GetImagesWithFilters gets images with a series of filters applied
func (ir *Runtime) GetImagesWithFilters(filters []string) ([]*Image, error) {
	filterFuncs, err := ir.createFilterFuncs(filters, nil)
	if err != nil {
		return nil, err
	}
	images, err := ir.GetImages()
	if err != nil {
		return nil, err
	}
	return FilterImages(images, filterFuncs), nil
}

func (i *Image) reloadImage() error {
	newImage, err := i.imageruntime.getImage(i.ID())
	if err != nil {
		return errors.Wrapf(err, "unable to reload image")
	}
	i.image = newImage
	return nil
}

// stringSha256 strips sha256 from user input
func stripSha256(name string) string {
	if strings.HasPrefix(name, "sha256:") && len(name) > 7 {
		return name[7:]
	}
	return name
}

// getLocalImage resolves an unknown input describing an image and
// returns an updated input name, and a storage.Image, or an error. It is used by NewFromLocal.
func (ir *Runtime) getLocalImage(inputName string) (string, *storage.Image, error) {
	imageError := fmt.Sprintf("unable to find '%s' in local storage", inputName)
	if inputName == "" {
		return "", nil, errors.Errorf("input name is blank")
	}
	// Check if the input name has a transport and if so strip it
	dest, err := alltransports.ParseImageName(inputName)
	if err == nil && dest.DockerReference() != nil {
		inputName = dest.DockerReference().String()
	}

	img, err := ir.getImage(stripSha256(inputName))
	if err == nil {
		return inputName, img, err
	}

	// container-storage wasn't able to find it in its current form
	// check if the input name has a tag, and if not, run it through
	// again
	decomposedImage, err := decompose(inputName)
	if err != nil {
		return "", nil, err
	}

	// The image has a registry name in it and we made sure we looked for it locally
	// with a tag.  It cannot be local.
	if decomposedImage.hasRegistry {
		return "", nil, errors.Wrapf(ErrNoSuchImage, imageError)
	}
	// if the image is saved with the repository localhost, searching with localhost prepended is necessary
	// We don't need to strip the sha because we have already determined it is not an ID
	ref, err := decomposedImage.referenceWithRegistry(DefaultLocalRegistry)
	if err != nil {
		return "", nil, err
	}
	img, err = ir.getImage(ref.String())
	if err == nil {
		return inputName, img, err
	}

	// grab all the local images
	images, err := ir.GetImages()
	if err != nil {
		return "", nil, err
	}

	// check the repotags of all images for a match
	repoImage, err := findImageInRepotags(decomposedImage, images)
	if err == nil {
		return inputName, repoImage, nil
	}

	return "", nil, errors.Wrapf(ErrNoSuchImage, err.Error())
}

// ID returns the image ID as a string
func (i *Image) ID() string {
	return i.image.ID
}

// IsReadOnly returns whether the image ID comes from a local store
func (i *Image) IsReadOnly() bool {
	return i.image.ReadOnly
}

// Digest returns the image's digest
func (i *Image) Digest() digest.Digest {
	return i.image.Digest
}

// Digests returns the image's digests
func (i *Image) Digests() []digest.Digest {
	return i.image.Digests
}

// GetManifest returns the image's manifest as a byte array
// and manifest type as a string.
func (i *Image) GetManifest(ctx context.Context, instanceDigest *digest.Digest) ([]byte, string, error) {
	imgSrcRef, err := i.toImageSourceRef(ctx)
	if err != nil {
		return nil, "", err
	}
	return imgSrcRef.GetManifest(ctx, instanceDigest)
}

// Manifest returns the image's manifest as a byte array
// and manifest type as a string.
func (i *Image) Manifest(ctx context.Context) ([]byte, string, error) {
	imgRef, err := i.toImageRef(ctx)
	if err != nil {
		return nil, "", err
	}
	return imgRef.Manifest(ctx)
}

// Names returns a string array of names associated with the image, which may be a mixture of tags and digests
func (i *Image) Names() []string {
	return i.image.Names
}

// NamesHistory returns a string array of names previously associated with the
// image, which may be a mixture of tags and digests
func (i *Image) NamesHistory() []string {
	if len(i.image.Names) > 0 && len(i.image.NamesHistory) > 0 &&
		// We compare the latest (time-referenced) tags for equality and skip
		// it in the history if they match to not display them twice.  We have
		// to compare like this, because `i.image.Names` (latest last) gets
		// appended on retag, whereas `i.image.NamesHistory` gets prepended
		// (latest first)
		i.image.Names[len(i.image.Names)-1] == i.image.NamesHistory[0] {
		return i.image.NamesHistory[1:]
	}
	return i.image.NamesHistory
}

// RepoTags returns a string array of repotags associated with the image
func (i *Image) RepoTags() ([]string, error) {
	var repoTags []string
	for _, name := range i.Names() {
		named, err := reference.ParseNormalizedNamed(name)
		if err != nil {
			return nil, err
		}
		if tagged, isTagged := named.(reference.NamedTagged); isTagged {
			repoTags = append(repoTags, tagged.String())
		}
	}
	return repoTags, nil
}

// RepoDigests returns a string array of repodigests associated with the image
func (i *Image) RepoDigests() ([]string, error) {
	var repoDigests []string
	added := make(map[string]struct{})

	for _, name := range i.Names() {
		for _, imageDigest := range append(i.Digests(), i.Digest()) {
			if imageDigest == "" {
				continue
			}

			named, err := reference.ParseNormalizedNamed(name)
			if err != nil {
				return nil, err
			}

			canonical, err := reference.WithDigest(reference.TrimNamed(named), imageDigest)
			if err != nil {
				return nil, err
			}

			if _, alreadyInList := added[canonical.String()]; !alreadyInList {
				repoDigests = append(repoDigests, canonical.String())
				added[canonical.String()] = struct{}{}
			}
		}
	}
	sort.Strings(repoDigests)
	return repoDigests, nil
}

// Created returns the time the image was created
func (i *Image) Created() time.Time {
	return i.image.Created
}

// TopLayer returns the top layer id as a string
func (i *Image) TopLayer() string {
	return i.image.TopLayer
}

// Remove an image; container removal for the image must be done
// outside the context of images
// TODO: the force param does nothing as of now. Need to move container
// handling logic here eventually.
func (i *Image) Remove(ctx context.Context, force bool) error {
	parent, err := i.GetParent(ctx)
	if err != nil {
		return err
	}
	if _, err := i.imageruntime.store.DeleteImage(i.ID(), true); err != nil {
		return err
	}
	i.newImageEvent(events.Remove)
	for parent != nil {
		nextParent, err := parent.GetParent(ctx)
		if err != nil {
			return err
		}
		children, err := parent.GetChildren(ctx)
		if err != nil {
			return err
		}
		// Do not remove if image is a base image and is not untagged, or if
		// the image has more children.
		if len(children) > 0 || len(parent.Names()) > 0 {
			return nil
		}
		id := parent.ID()
		if _, err := i.imageruntime.store.DeleteImage(id, true); err != nil {
			logrus.Debugf("unable to remove intermediate image %q: %v", id, err)
		} else {
			fmt.Println(id)
		}
		parent = nextParent
	}
	return nil
}

// getImage retrieves an image matching the given name or hash from system
// storage
// If no matching image can be found, an error is returned
func (ir *Runtime) getImage(image string) (*storage.Image, error) {
	var img *storage.Image
	ref, err := is.Transport.ParseStoreReference(ir.store, image)
	if err == nil {
		img, err = is.Transport.GetStoreImage(ir.store, ref)
	}
	if err != nil {
		img2, err2 := ir.store.Image(image)
		if err2 != nil {
			if ref == nil {
				return nil, errors.Wrapf(err, "error parsing reference to image %q", image)
			}
			return nil, errors.Wrapf(err, "unable to locate image %q", image)
		}
		img = img2
	}
	return img, nil
}

// GetImages retrieves all images present in storage
func (ir *Runtime) GetImages() ([]*Image, error) {
	return ir.getImages(false)
}

// GetRWImages retrieves all read/write images present in storage
func (ir *Runtime) GetRWImages() ([]*Image, error) {
	return ir.getImages(true)
}

// getImages retrieves all images present in storage
func (ir *Runtime) getImages(rwOnly bool) ([]*Image, error) {
	var newImages []*Image
	images, err := ir.store.Images()
	if err != nil {
		return nil, err
	}
	for _, i := range images {
		if rwOnly && i.ReadOnly {
			continue
		}
		// iterating over these, be careful to not iterate on the literal
		// pointer.
		image := i
		img := ir.newFromStorage(&image)
		newImages = append(newImages, img)
	}
	return newImages, nil
}

// getImageDigest creates an image object and uses the hex value of the digest as the image ID
// for parsing the store reference
func getImageDigest(ctx context.Context, src types.ImageReference, sc *types.SystemContext) (string, error) {
	newImg, err := src.NewImage(ctx, sc)
	if err != nil {
		return "", err
	}
	defer func() {
		if err := newImg.Close(); err != nil {
			logrus.Errorf("failed to close image: %q", err)
		}
	}()
	imageDigest := newImg.ConfigInfo().Digest
	if err = imageDigest.Validate(); err != nil {
		return "", errors.Wrapf(err, "error getting config info")
	}
	return "@" + imageDigest.Hex(), nil
}

// NormalizedTag returns the canonical version of tag for use in Image.Names()
func NormalizedTag(tag string) (reference.Named, error) {
	decomposedTag, err := decompose(tag)
	if err != nil {
		return nil, err
	}
	// If the input doesn't specify a registry, set the registry to localhost
	var ref reference.Named
	if !decomposedTag.hasRegistry {
		ref, err = decomposedTag.referenceWithRegistry(DefaultLocalRegistry)
		if err != nil {
			return nil, err
		}
	} else {
		ref, err = decomposedTag.normalizedReference()
		if err != nil {
			return nil, err
		}
	}
	// If the input does not have a tag, we need to add one (latest)
	ref = reference.TagNameOnly(ref)
	return ref, nil
}

// TagImage adds a tag to the given image
func (i *Image) TagImage(tag string) error {
	if err := i.reloadImage(); err != nil {
		return err
	}
	ref, err := NormalizedTag(tag)
	if err != nil {
		return err
	}
	tags := i.Names()
	if util.StringInSlice(ref.String(), tags) {
		return nil
	}
	tags = append(tags, ref.String())
	if err := i.imageruntime.store.SetNames(i.ID(), tags); err != nil {
		return err
	}
	if err := i.reloadImage(); err != nil {
		return err
	}
	i.newImageEvent(events.Tag)
	return nil
}

// UntagImage removes a tag from the given image
func (i *Image) UntagImage(tag string) error {
	if err := i.reloadImage(); err != nil {
		return err
	}
	var newTags []string
	tags := i.Names()
	if !util.StringInSlice(tag, tags) {
		return nil
	}
	for _, t := range tags {
		if tag != t {
			newTags = append(newTags, t)
		}
	}
	if err := i.imageruntime.store.SetNames(i.ID(), newTags); err != nil {
		return err
	}
	if err := i.reloadImage(); err != nil {
		return err
	}
	i.newImageEvent(events.Untag)
	return nil
}

// PushImageToHeuristicDestination pushes the given image to "destination", which is heuristically parsed.
// Use PushImageToReference if the destination is known precisely.
func (i *Image) PushImageToHeuristicDestination(ctx context.Context, destination, manifestMIMEType, authFile, digestFile, signaturePolicyPath string, writer io.Writer, forceCompress bool, signingOptions SigningOptions, dockerRegistryOptions *DockerRegistryOptions, additionalDockerArchiveTags []reference.NamedTagged) error {
	if destination == "" {
		return errors.Wrapf(syscall.EINVAL, "destination image name must be specified")
	}

	// Get the destination Image Reference
	dest, err := alltransports.ParseImageName(destination)
	if err != nil {
		if hasTransport(destination) {
			return errors.Wrapf(err, "error getting destination imageReference for %q", destination)
		}
		// Try adding the images default transport
		destination2 := DefaultTransport + destination
		dest, err = alltransports.ParseImageName(destination2)
		if err != nil {
			return err
		}
	}
	return i.PushImageToReference(ctx, dest, manifestMIMEType, authFile, digestFile, signaturePolicyPath, writer, forceCompress, signingOptions, dockerRegistryOptions, additionalDockerArchiveTags)
}

// PushImageToReference pushes the given image to a location described by the given path
func (i *Image) PushImageToReference(ctx context.Context, dest types.ImageReference, manifestMIMEType, authFile, digestFile, signaturePolicyPath string, writer io.Writer, forceCompress bool, signingOptions SigningOptions, dockerRegistryOptions *DockerRegistryOptions, additionalDockerArchiveTags []reference.NamedTagged) error {
	sc := GetSystemContext(signaturePolicyPath, authFile, forceCompress)
	sc.BlobInfoCacheDir = filepath.Join(i.imageruntime.store.GraphRoot(), "cache")

	policyContext, err := getPolicyContext(sc)
	if err != nil {
		return err
	}
	defer func() {
		if err := policyContext.Destroy(); err != nil {
			logrus.Errorf("failed to destroy policy context: %q", err)
		}
	}()

	// Look up the source image, expecting it to be in local storage
	src, err := is.Transport.ParseStoreReference(i.imageruntime.store, i.ID())
	if err != nil {
		return errors.Wrapf(err, "error getting source imageReference for %q", i.InputName)
	}
	copyOptions := getCopyOptions(sc, writer, nil, dockerRegistryOptions, signingOptions, manifestMIMEType, additionalDockerArchiveTags)
	copyOptions.DestinationCtx.SystemRegistriesConfPath = registries.SystemRegistriesConfPath() // FIXME: Set this more globally.  Probably no reason not to have it in every types.SystemContext, and to compute the value just once in one place.
	// Copy the image to the remote destination
	manifestBytes, err := cp.Image(ctx, policyContext, dest, src, copyOptions)
	if err != nil {
		return errors.Wrapf(err, "Error copying image to the remote destination")
	}
	digest, err := manifest.Digest(manifestBytes)
	if err != nil {
		return errors.Wrapf(err, "error computing digest of manifest of new image %q", transports.ImageName(dest))
	}

	logrus.Debugf("Successfully pushed %s with digest %s", transports.ImageName(dest), digest.String())

	if digestFile != "" {
		if err = ioutil.WriteFile(digestFile, []byte(digest.String()), 0644); err != nil {
			return errors.Wrapf(err, "failed to write digest to file %q", digestFile)
		}
	}
	i.newImageEvent(events.Push)
	return nil
}

// MatchesID returns a bool based on if the input id
// matches the image's id
// TODO: This isn't used anywhere, so remove it
func (i *Image) MatchesID(id string) bool {
	return strings.HasPrefix(i.ID(), id)
}

// ToImageRef returns an image reference type from an image
// TODO: Hopefully we can remove this exported function for mheon
func (i *Image) ToImageRef(ctx context.Context) (types.Image, error) {
	return i.toImageRef(ctx)
}

// toImageSourceRef returns an ImageSource Reference type from an image
func (i *Image) toImageSourceRef(ctx context.Context) (types.ImageSource, error) {
	if i == nil {
		return nil, errors.Errorf("cannot convert nil image to image source reference")
	}
	if i.imgSrcRef == nil {
		ref, err := is.Transport.ParseStoreReference(i.imageruntime.store, "@"+i.ID())
		if err != nil {
			return nil, errors.Wrapf(err, "error parsing reference to image %q", i.ID())
		}
		imgSrcRef, err := ref.NewImageSource(ctx, nil)
		if err != nil {
			return nil, errors.Wrapf(err, "error reading image %q as image source", i.ID())
		}
		i.imgSrcRef = imgSrcRef
	}
	return i.imgSrcRef, nil
}

//Size returns the size of the image
func (i *Image) Size(ctx context.Context) (*uint64, error) {
	sum, err := i.imageruntime.store.ImageSize(i.ID())
	if err == nil && sum >= 0 {
		usum := uint64(sum)
		return &usum, nil
	}
	return nil, errors.Wrap(err, "unable to determine size")
}

// toImageRef returns an Image Reference type from an image
func (i *Image) toImageRef(ctx context.Context) (types.Image, error) {
	if i == nil {
		return nil, errors.Errorf("cannot convert nil image to image reference")
	}
	imgSrcRef, err := i.toImageSourceRef(ctx)
	if err != nil {
		return nil, err
	}
	if i.imgRef == nil {
		systemContext := &types.SystemContext{}
		unparsedDefaultInstance := image.UnparsedInstance(imgSrcRef, nil)
		imgRef, err := image.FromUnparsedImage(ctx, systemContext, unparsedDefaultInstance)
		if err != nil {
			// check for a "tried-to-treat-a-bare-list-like-a-runnable-image" problem, else
			// return info about the not-a-bare-list runnable image part of this storage.Image
			if manifestBytes, manifestType, err2 := imgSrcRef.GetManifest(ctx, nil); err2 == nil {
				if manifest.MIMETypeIsMultiImage(manifestType) {
					if list, err3 := manifest.ListFromBlob(manifestBytes, manifestType); err3 == nil {
						switch manifestType {
						case ociv1.MediaTypeImageIndex:
							err = errors.Wrapf(ErrImageIsBareList, "%q is an image index", i.InputName)
						case manifest.DockerV2ListMediaType:
							err = errors.Wrapf(ErrImageIsBareList, "%q is a manifest list", i.InputName)
						default:
							err = errors.Wrapf(ErrImageIsBareList, "%q", i.InputName)
						}
						for _, instanceDigest := range list.Instances() {
							instance := instanceDigest
							unparsedInstance := image.UnparsedInstance(imgSrcRef, &instance)
							if imgRef2, err4 := image.FromUnparsedImage(ctx, systemContext, unparsedInstance); err4 == nil {
								imgRef = imgRef2
								err = nil
								break
							}
						}
					}
				}
			}
			if err != nil {
				return nil, errors.Wrapf(err, "error reading image %q as image", i.ID())
			}
		}
		i.imgRef = imgRef
	}
	return i.imgRef, nil
}

// DriverData gets the driver data from the store on a layer
func (i *Image) DriverData() (*driver.Data, error) {
	return driver.GetDriverData(i.imageruntime.store, i.TopLayer())
}

// Layer returns the image's top layer
func (i *Image) Layer() (*storage.Layer, error) {
	return i.imageruntime.store.Layer(i.image.TopLayer)
}

// History contains the history information of an image
type History struct {
	ID        string     `json:"id"`
	Created   *time.Time `json:"created"`
	CreatedBy string     `json:"createdBy"`
	Size      int64      `json:"size"`
	Comment   string     `json:"comment"`
	Tags      []string   `json:"tags"`
}

// History gets the history of an image and the IDs of images that are part of
// its history
func (i *Image) History(ctx context.Context) ([]*History, error) {
	img, err := i.toImageRef(ctx)
	if err != nil {
		if errors.Cause(err) == ErrImageIsBareList {
			return nil, nil
		}
		return nil, err
	}
	oci, err := img.OCIConfig(ctx)
	if err != nil {
		return nil, err
	}

	// Build a mapping from top-layer to image ID.
	images, err := i.imageruntime.GetImages()
	if err != nil {
		return nil, err
	}
	topLayerMap := make(map[string]string)
	for _, image := range images {
		if _, exists := topLayerMap[image.TopLayer()]; !exists {
			topLayerMap[image.TopLayer()] = image.ID()
		}
	}

	var allHistory []*History
	var layer *storage.Layer

	// Check if we have an actual top layer to prevent lookup errors.
	if i.TopLayer() != "" {
		layer, err = i.imageruntime.store.Layer(i.TopLayer())
		if err != nil {
			return nil, err
		}
	}

	// Iterate in reverse order over the history entries, and lookup the
	// corresponding image ID, size and get the next later if needed.
	numHistories := len(oci.History) - 1
	for x := numHistories; x >= 0; x-- {
		var size int64

		id := "<missing>"
		if x == numHistories {
			id = i.ID()
		}
		if layer != nil {
			if !oci.History[x].EmptyLayer {
				size = layer.UncompressedSize
			}
			if imageID, exists := topLayerMap[layer.ID]; exists {
				id = imageID
				// Delete the entry to avoid reusing it for following history items.
				delete(topLayerMap, layer.ID)
			}
		}
		h := History{
			ID:        id,
			Created:   oci.History[x].Created,
			CreatedBy: oci.History[x].CreatedBy,
			Size:      size,
			Comment:   oci.History[x].Comment,
		}
		if layer != nil {
			h.Tags = layer.Names
		}
		allHistory = append(allHistory, &h)

		if layer != nil && layer.Parent != "" && !oci.History[x].EmptyLayer {
			layer, err = i.imageruntime.store.Layer(layer.Parent)
			if err != nil {
				return nil, err
			}
		}
	}

	return allHistory, nil
}

// Dangling returns a bool if the image is "dangling"
func (i *Image) Dangling() bool {
	return len(i.Names()) == 0
}

// Labels returns the image's labels
func (i *Image) Labels(ctx context.Context) (map[string]string, error) {
	imgInspect, err := i.imageInspectInfo(ctx)
	if err != nil {
		return nil, nil
	}
	return imgInspect.Labels, nil
}

// GetLabel Returns a case-insensitive match of a given label
func (i *Image) GetLabel(ctx context.Context, label string) (string, error) {
	imageLabels, err := i.Labels(ctx)
	if err != nil {
		return "", err
	}
	for k, v := range imageLabels {
		if strings.ToLower(k) == strings.ToLower(label) {
			return v, nil
		}
	}
	return "", nil
}

// Annotations returns the annotations of an image
func (i *Image) Annotations(ctx context.Context) (map[string]string, error) {
	imageManifest, manifestType, err := i.Manifest(ctx)
	if err != nil {
		imageManifest, manifestType, err = i.GetManifest(ctx, nil)
		if err != nil {
			return nil, err
		}
	}
	annotations := make(map[string]string)
	if manifestType == ociv1.MediaTypeImageManifest {
		var m ociv1.Manifest
		if err := json.Unmarshal(imageManifest, &m); err == nil {
			for k, v := range m.Annotations {
				annotations[k] = v
			}
		}
	}
	return annotations, nil
}

// ociv1Image converts an image to an imgref and then returns its config blob
// converted to an ociv1 image type
func (i *Image) ociv1Image(ctx context.Context) (*ociv1.Image, error) {
	imgRef, err := i.toImageRef(ctx)
	if err != nil {
		return nil, err
	}
	return imgRef.OCIConfig(ctx)
}

func (i *Image) imageInspectInfo(ctx context.Context) (*types.ImageInspectInfo, error) {
	if i.inspectInfo == nil {
		ic, err := i.toImageRef(ctx)
		if err != nil {
			return nil, err
		}
		imgInspect, err := ic.Inspect(ctx)
		if err != nil {
			return nil, err
		}
		i.inspectInfo = imgInspect
	}
	return i.inspectInfo, nil
}

func (i *Image) inspect(ctx context.Context, calculateSize bool) (*inspect.ImageData, error) {
	ociv1Img, err := i.ociv1Image(ctx)
	if err != nil {
		ociv1Img = &ociv1.Image{}
	}
	info, err := i.imageInspectInfo(ctx)
	if err != nil {
		info = &types.ImageInspectInfo{}
	}
	annotations, err := i.Annotations(ctx)
	if err != nil {
		return nil, err
	}

	size := int64(-1)
	if calculateSize {
		if usize, err := i.Size(ctx); err == nil {
			size = int64(*usize)
		}
	}

	repoTags, err := i.RepoTags()
	if err != nil {
		return nil, err
	}

	repoDigests, err := i.RepoDigests()
	if err != nil {
		return nil, err
	}

	driver, err := i.DriverData()
	if err != nil {
		return nil, err
	}

	_, manifestType, err := i.GetManifest(ctx, nil)
	if err != nil {
		return nil, errors.Wrapf(err, "unable to determine manifest type")
	}
	comment, err := i.Comment(ctx, manifestType)
	if err != nil {
		return nil, err
	}

	data := &inspect.ImageData{
		ID:           i.ID(),
		RepoTags:     repoTags,
		RepoDigests:  repoDigests,
		Comment:      comment,
		Created:      ociv1Img.Created,
		Author:       ociv1Img.Author,
		Architecture: ociv1Img.Architecture,
		Os:           ociv1Img.OS,
		Config:       &ociv1Img.Config,
		Version:      info.DockerVersion,
		Size:         size,
		VirtualSize:  size,
		Annotations:  annotations,
		Digest:       i.Digest(),
		Labels:       info.Labels,
		RootFS: &inspect.RootFS{
			Type:   ociv1Img.RootFS.Type,
			Layers: ociv1Img.RootFS.DiffIDs,
		},
		GraphDriver:  driver,
		ManifestType: manifestType,
		User:         ociv1Img.Config.User,
		History:      ociv1Img.History,
		NamesHistory: i.NamesHistory(),
	}
	if manifestType == manifest.DockerV2Schema2MediaType {
		hc, err := i.GetHealthCheck(ctx)
		if err != nil {
			return nil, err
		}
		if hc != nil {
			data.HealthCheck = hc
		}
	}
	return data, nil
}

// Inspect returns an image's inspect data
func (i *Image) Inspect(ctx context.Context) (*inspect.ImageData, error) {
	span, _ := opentracing.StartSpanFromContext(ctx, "imageInspect")

	span.SetTag("type", "image")
	defer span.Finish()

	return i.inspect(ctx, true)
}

// InspectNoSize returns an image's inspect data without calculating the size for the image
func (i *Image) InspectNoSize(ctx context.Context) (*inspect.ImageData, error) {
	span, _ := opentracing.StartSpanFromContext(ctx, "imageInspectNoSize")

	span.SetTag("type", "image")
	defer span.Finish()

	return i.inspect(ctx, false)
}

// Import imports and image into the store and returns an image
func (ir *Runtime) Import(ctx context.Context, path, reference string, writer io.Writer, signingOptions SigningOptions, imageConfig ociv1.Image) (*Image, error) {
	src, err := tarball.Transport.ParseReference(path)
	if err != nil {
		return nil, errors.Wrapf(err, "error parsing image name %q", path)
	}

	updater, ok := src.(tarball.ConfigUpdater)
	if !ok {
		return nil, errors.Wrapf(err, "unexpected type, a tarball reference should implement tarball.ConfigUpdater")
	}

	annotations := make(map[string]string)

	//	config imgspecv1.Image
	err = updater.ConfigUpdate(imageConfig, annotations)
	if err != nil {
		return nil, errors.Wrapf(err, "error updating image config")
	}

	sc := GetSystemContext("", "", false)

	// if reference not given, get the image digest
	if reference == "" {
		reference, err = getImageDigest(ctx, src, sc)
		if err != nil {
			return nil, err
		}
	}
	policyContext, err := getPolicyContext(sc)
	if err != nil {
		return nil, err
	}
	defer func() {
		if err := policyContext.Destroy(); err != nil {
			logrus.Errorf("failed to destroy policy context: %q", err)
		}
	}()
	copyOptions := getCopyOptions(sc, writer, nil, nil, signingOptions, "", nil)
	dest, err := is.Transport.ParseStoreReference(ir.store, reference)
	if err != nil {
		return nil, errors.Wrapf(err, "error getting image reference for %q", reference)
	}
	_, err = cp.Image(ctx, policyContext, dest, src, copyOptions)
	if err != nil {
		return nil, err
	}
	newImage, err := ir.NewFromLocal(reference)
	if err == nil {
		newImage.newImageEvent(events.Import)
	}
	return newImage, err
}

// MatchRepoTag takes a string and tries to match it against an
// image's repotags
func (i *Image) MatchRepoTag(input string) (string, error) {
	results := make(map[int][]string)
	var maxCount int
	// first check if we have an exact match with the input
	if util.StringInSlice(input, i.Names()) {
		return input, nil
	}
	// next check if we are missing the tag
	dcImage, err := decompose(input)
	if err != nil {
		return "", err
	}
	imageRegistry, imageName, imageSuspiciousTagValueForSearch := dcImage.suspiciousRefNameTagValuesForSearch()
	for _, repoName := range i.Names() {
		count := 0
		dcRepoName, err := decompose(repoName)
		if err != nil {
			return "", err
		}
		repoNameRegistry, repoNameName, repoNameSuspiciousTagValueForSearch := dcRepoName.suspiciousRefNameTagValuesForSearch()
		if repoNameRegistry == imageRegistry && imageRegistry != "" {
			count++
		}
		if repoNameName == imageName && imageName != "" {
			count++
		} else if splitString(repoNameName) == splitString(imageName) {
			count++
		}
		if repoNameSuspiciousTagValueForSearch == imageSuspiciousTagValueForSearch {
			count++
		}
		results[count] = append(results[count], repoName)
		if count > maxCount {
			maxCount = count
		}
	}
	if maxCount == 0 {
		return "", ErrRepoTagNotFound
	}
	if len(results[maxCount]) > 1 {
		return "", errors.Errorf("user input matched multiple repotags for the image")
	}
	return results[maxCount][0], nil
}

// splitString splits input string by / and returns the last array item
func splitString(input string) string {
	split := strings.Split(input, "/")
	return split[len(split)-1]
}

// IsParent goes through the layers in the store and checks if i.TopLayer is
// the parent of any other layer in store. Double check that image with that
// layer exists as well.
func (i *Image) IsParent(ctx context.Context) (bool, error) {
	children, err := i.getChildren(ctx, 1)
	if err != nil {
		if errors.Cause(err) == ErrImageIsBareList {
			return false, nil
		}
		return false, err
	}
	return len(children) > 0, nil
}

// historiesMatch returns the number of entries in the histories which have the
// same contents
func historiesMatch(a, b []imgspecv1.History) int {
	i := 0
	for i < len(a) && i < len(b) {
		if a[i].Created != nil && b[i].Created == nil {
			return i
		}
		if a[i].Created == nil && b[i].Created != nil {
			return i
		}
		if a[i].Created != nil && b[i].Created != nil {
			if !a[i].Created.Equal(*(b[i].Created)) {
				return i
			}
		}
		if a[i].CreatedBy != b[i].CreatedBy {
			return i
		}
		if a[i].Author != b[i].Author {
			return i
		}
		if a[i].Comment != b[i].Comment {
			return i
		}
		if a[i].EmptyLayer != b[i].EmptyLayer {
			return i
		}
		i++
	}
	return i
}

// areParentAndChild checks diff ID and history in the two images and return
// true if the second should be considered to be directly based on the first
func areParentAndChild(parent, child *imgspecv1.Image) bool {
	// the child and candidate parent should share all of the
	// candidate parent's diff IDs, which together would have
	// controlled which layers were used
	if len(parent.RootFS.DiffIDs) > len(child.RootFS.DiffIDs) {
		return false
	}
	childUsesCandidateDiffs := true
	for i := range parent.RootFS.DiffIDs {
		if child.RootFS.DiffIDs[i] != parent.RootFS.DiffIDs[i] {
			childUsesCandidateDiffs = false
			break
		}
	}
	if !childUsesCandidateDiffs {
		return false
	}
	// the child should have the same history as the parent, plus
	// one more entry
	if len(parent.History)+1 != len(child.History) {
		return false
	}
	if historiesMatch(parent.History, child.History) != len(parent.History) {
		return false
	}
	return true
}

// GetParent returns the image ID of the parent. Return nil if a parent is not found.
func (i *Image) GetParent(ctx context.Context) (*Image, error) {
	var childLayer *storage.Layer
	images, err := i.imageruntime.GetImages()
	if err != nil {
		return nil, err
	}
	if i.TopLayer() != "" {
		if childLayer, err = i.imageruntime.store.Layer(i.TopLayer()); err != nil {
			return nil, err
		}
	}
	// fetch the configuration for the child image
	child, err := i.ociv1Image(ctx)
	if err != nil {
		if errors.Cause(err) == ErrImageIsBareList {
			return nil, nil
		}
		return nil, err
	}
	for _, img := range images {
		if img.ID() == i.ID() {
			continue
		}
		candidateLayer := img.TopLayer()
		// as a child, our top layer, if we have one, is either the
		// candidate parent's layer, or one that's derived from it, so
		// skip over any candidate image where we know that isn't the
		// case
		if childLayer != nil {
			// The child has at least one layer, so a parent would
			// have a top layer that's either the same as the child's
			// top layer or the top layer's recorded parent layer,
			// which could be an empty value.
			if candidateLayer != childLayer.Parent && candidateLayer != childLayer.ID {
				continue
			}
		} else {
			// The child has no layers, but the candidate does.
			if candidateLayer != "" {
				continue
			}
		}
		// fetch the configuration for the candidate image
		candidate, err := img.ociv1Image(ctx)
		if err != nil {
			return nil, err
		}
		// compare them
		if areParentAndChild(candidate, child) {
			return img, nil
		}
	}
	return nil, nil
}

// GetChildren returns a list of the imageIDs that depend on the image
func (i *Image) GetChildren(ctx context.Context) ([]string, error) {
	children, err := i.getChildren(ctx, 0)
	if err != nil {
		if errors.Cause(err) == ErrImageIsBareList {
			return nil, nil
		}
		return nil, err
	}
	return children, nil
}

// getChildren returns a list of at most "max" imageIDs that depend on the image
func (i *Image) getChildren(ctx context.Context, max int) ([]string, error) {
	var children []string

	if _, err := i.toImageRef(ctx); err != nil {
		return nil, nil
	}

	images, err := i.imageruntime.GetImages()
	if err != nil {
		return nil, err
	}

	// fetch the configuration for the parent image
	parent, err := i.ociv1Image(ctx)
	if err != nil {
		return nil, err
	}
	parentLayer := i.TopLayer()

	for _, img := range images {
		if img.ID() == i.ID() {
			continue
		}
		if img.TopLayer() == "" {
			if parentLayer != "" {
				// this image has no layers, but we do, so
				// it can't be derived from this one
				continue
			}
		} else {
			candidateLayer, err := img.Layer()
			if err != nil {
				return nil, err
			}
			// if this image's top layer is not our top layer, and is not
			// based on our top layer, we can skip it
			if candidateLayer.Parent != parentLayer && candidateLayer.ID != parentLayer {
				continue
			}
		}
		// fetch the configuration for the candidate image
		candidate, err := img.ociv1Image(ctx)
		if err != nil {
			return nil, err
		}
		// compare them
		if areParentAndChild(parent, candidate) {
			children = append(children, img.ID())
		}
		// if we're not building an exhaustive list, maybe we're done?
		if max > 0 && len(children) >= max {
			break
		}
	}
	return children, nil
}

// InputIsID returns a bool if the user input for an image
// is the image's partial or full id
func (i *Image) InputIsID() bool {
	return strings.HasPrefix(i.ID(), i.InputName)
}

// Containers a list of container IDs associated with the image
func (i *Image) Containers() ([]string, error) {
	containers, err := i.imageruntime.store.Containers()
	if err != nil {
		return nil, err
	}
	var imageContainers []string
	for _, c := range containers {
		if c.ImageID == i.ID() {
			imageContainers = append(imageContainers, c.ID)
		}
	}
	return imageContainers, err
}

// Comment returns the Comment for an image depending on its ManifestType
func (i *Image) Comment(ctx context.Context, manifestType string) (string, error) {
	if manifestType == manifest.DockerV2Schema2MediaType {
		imgRef, err := i.toImageRef(ctx)
		if err != nil {
			return "", errors.Wrapf(err, "unable to create image reference from image")
		}
		blob, err := imgRef.ConfigBlob(ctx)
		if err != nil {
			return "", errors.Wrapf(err, "unable to get config blob from image")
		}
		b := manifest.Schema2Image{}
		if err := json.Unmarshal(blob, &b); err != nil {
			return "", err
		}
		return b.Comment, nil
	}
	ociv1Img, err := i.ociv1Image(ctx)
	if err != nil {
		if errors.Cause(err) == ErrImageIsBareList {
			return "", nil
		}
		return "", err
	}
	if len(ociv1Img.History) > 0 {
		return ociv1Img.History[0].Comment, nil
	}
	return "", nil
}

// Save writes a container image to the filesystem
func (i *Image) Save(ctx context.Context, source, format, output string, moreTags []string, quiet, compress bool) error {
	var (
		writer       io.Writer
		destRef      types.ImageReference
		manifestType string
		err          error
	)

	if quiet {
		writer = os.Stderr
	}
	switch format {
	case "oci-archive":
		destImageName := imageNameForSaveDestination(i, source)
		destRef, err = ociarchive.NewReference(output, destImageName) // destImageName may be ""
		if err != nil {
			return errors.Wrapf(err, "error getting OCI archive ImageReference for (%q, %q)", output, destImageName)
		}
	case "oci-dir":
		destRef, err = directory.NewReference(output)
		if err != nil {
			return errors.Wrapf(err, "error getting directory ImageReference for %q", output)
		}
		manifestType = imgspecv1.MediaTypeImageManifest
	case "docker-dir":
		destRef, err = directory.NewReference(output)
		if err != nil {
			return errors.Wrapf(err, "error getting directory ImageReference for %q", output)
		}
		manifestType = manifest.DockerV2Schema2MediaType
	case "docker-archive", "":
		dst := output
		destImageName := imageNameForSaveDestination(i, source)
		if destImageName != "" {
			dst = fmt.Sprintf("%s:%s", dst, destImageName)
		}
		destRef, err = dockerarchive.ParseReference(dst) // FIXME? Add dockerarchive.NewReference
		if err != nil {
			return errors.Wrapf(err, "error getting Docker archive ImageReference for %q", dst)
		}
	default:
		return errors.Errorf("unknown format option %q", format)
	}
	// supports saving multiple tags to the same tar archive
	var additionaltags []reference.NamedTagged
	if len(moreTags) > 0 {
		additionaltags, err = GetAdditionalTags(moreTags)
		if err != nil {
			return err
		}
	}
	if err := i.PushImageToReference(ctx, destRef, manifestType, "", "", "", writer, compress, SigningOptions{}, &DockerRegistryOptions{}, additionaltags); err != nil {
		return errors.Wrapf(err, "unable to save %q", source)
	}
	i.newImageEvent(events.Save)
	return nil
}

// GetConfigBlob returns a schema2image.  If the image is not a schema2, then
// it will return an error
func (i *Image) GetConfigBlob(ctx context.Context) (*manifest.Schema2Image, error) {
	imageRef, err := i.toImageRef(ctx)
	if err != nil {
		return nil, err
	}
	b, err := imageRef.ConfigBlob(ctx)
	if err != nil {
		return nil, errors.Wrapf(err, "unable to get config blob for %s", i.ID())
	}
	blob := manifest.Schema2Image{}
	if err := json.Unmarshal(b, &blob); err != nil {
		return nil, errors.Wrapf(err, "unable to parse image blob for %s", i.ID())
	}
	return &blob, nil

}

// GetHealthCheck returns a HealthConfig for an image.  This function only works with
// schema2 images.
func (i *Image) GetHealthCheck(ctx context.Context) (*manifest.Schema2HealthConfig, error) {
	configBlob, err := i.GetConfigBlob(ctx)
	if err != nil {
		return nil, err
	}
	return configBlob.ContainerConfig.Healthcheck, nil
}

// newImageEvent creates a new event based on an image
func (ir *Runtime) newImageEvent(status events.Status, name string) {
	e := events.NewEvent(status)
	e.Type = events.Image
	e.Name = name
	if err := ir.Eventer.Write(e); err != nil {
		logrus.Infof("unable to write event to %s", ir.EventsLogFilePath)
	}
}

// newImageEvent creates a new event based on an image
func (i *Image) newImageEvent(status events.Status) {
	e := events.NewEvent(status)
	e.ID = i.ID()
	e.Type = events.Image
	if len(i.Names()) > 0 {
		e.Name = i.Names()[0]
	}
	if err := i.imageruntime.Eventer.Write(e); err != nil {
		logrus.Infof("unable to write event to %s", i.imageruntime.EventsLogFilePath)
	}
}

// LayerInfo keeps information of single layer
type LayerInfo struct {
	// Layer ID
	ID string
	// Parent ID of current layer.
	ParentID string
	// ChildID of current layer.
	// there can be multiple children in case of fork
	ChildID []string
	// RepoTag will have image repo names, if layer is top layer of image
	RepoTags []string
	// Size stores Uncompressed size of layer.
	Size int64
}

// GetLayersMapWithImageInfo returns map of image-layers, with associated information like RepoTags, parent and list of child layers.
func GetLayersMapWithImageInfo(imageruntime *Runtime) (map[string]*LayerInfo, error) {

	// Memory allocated to store map of layers with key LayerID.
	// Map will build dependency chain with ParentID and ChildID(s)
	layerInfoMap := make(map[string]*LayerInfo)

	// scan all layers & fill size and parent id for each layer in layerInfoMap
	layers, err := imageruntime.store.Layers()
	if err != nil {
		return nil, err
	}
	for _, layer := range layers {
		_, ok := layerInfoMap[layer.ID]
		if !ok {
			layerInfoMap[layer.ID] = &LayerInfo{
				ID:       layer.ID,
				Size:     layer.UncompressedSize,
				ParentID: layer.Parent,
			}
		} else {
			return nil, fmt.Errorf("detected multiple layers with the same ID %q", layer.ID)
		}
	}

	// scan all layers & add all childid's for each layers to layerInfo
	for _, layer := range layers {
		_, ok := layerInfoMap[layer.ID]
		if ok {
			if layer.Parent != "" {
				layerInfoMap[layer.Parent].ChildID = append(layerInfoMap[layer.Parent].ChildID, layer.ID)
			}
		} else {
			return nil, fmt.Errorf("lookup error: layer-id  %s, not found", layer.ID)
		}
	}

	// Add the Repo Tags to Top layer of each image.
	imgs, err := imageruntime.store.Images()
	if err != nil {
		return nil, err
	}
	layerInfoMap[""] = &LayerInfo{}
	for _, img := range imgs {
		e, ok := layerInfoMap[img.TopLayer]
		if !ok {
			return nil, fmt.Errorf("top-layer for image %s not found local store", img.ID)
		}
		e.RepoTags = append(e.RepoTags, img.Names...)
	}
	return layerInfoMap, nil
}

// BuildImageHierarchyMap stores hierarchy of images such that all parent layers using which image is built are stored in imageInfo
// Layers are added such that  (Start)RootLayer->...intermediate Parent Layer(s)-> TopLayer(End)
func BuildImageHierarchyMap(imageInfo *InfoImage, layerMap map[string]*LayerInfo, layerID string) error {
	if layerID == "" {
		return nil
	}
	ll, ok := layerMap[layerID]
	if !ok {
		return fmt.Errorf("lookup error: layerid  %s not found", layerID)
	}
	if err := BuildImageHierarchyMap(imageInfo, layerMap, ll.ParentID); err != nil {
		return err
	}

	imageInfo.Layers = append(imageInfo.Layers, *ll)
	return nil
}