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
|
package ociindex
import (
"encoding/json"
"io"
"os"
"path"
"github.com/gofrs/flock"
ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
"github.com/pkg/errors"
)
const (
// lockFileSuffix is the suffix of the lock file
lockFileSuffix = ".lock"
)
type StoreIndex struct {
indexPath string
lockPath string
layoutPath string
}
func NewStoreIndex(storePath string) StoreIndex {
indexPath := path.Join(storePath, ocispecs.ImageIndexFile)
layoutPath := path.Join(storePath, ocispecs.ImageLayoutFile)
return StoreIndex{
indexPath: indexPath,
lockPath: indexPath + lockFileSuffix,
layoutPath: layoutPath,
}
}
func (s StoreIndex) Read() (*ocispecs.Index, error) {
lock := flock.New(s.lockPath)
locked, err := lock.TryRLock()
if err != nil {
return nil, errors.Wrapf(err, "could not lock %s", s.lockPath)
}
if !locked {
return nil, errors.Errorf("could not lock %s", s.lockPath)
}
defer func() {
lock.Unlock()
os.RemoveAll(s.lockPath)
}()
b, err := os.ReadFile(s.indexPath)
if err != nil {
return nil, errors.Wrapf(err, "could not read %s", s.indexPath)
}
var idx ocispecs.Index
if err := json.Unmarshal(b, &idx); err != nil {
return nil, errors.Wrapf(err, "could not unmarshal %s (%q)", s.indexPath, string(b))
}
return &idx, nil
}
func (s StoreIndex) Put(tag string, desc ocispecs.Descriptor) error {
// lock the store to prevent concurrent access
lock := flock.New(s.lockPath)
locked, err := lock.TryLock()
if err != nil {
return errors.Wrapf(err, "could not lock %s", s.lockPath)
}
if !locked {
return errors.Errorf("could not lock %s", s.lockPath)
}
defer func() {
lock.Unlock()
os.RemoveAll(s.lockPath)
}()
// create the oci-layout file
layout := ocispecs.ImageLayout{
Version: ocispecs.ImageLayoutVersion,
}
layoutData, err := json.Marshal(layout)
if err != nil {
return err
}
if err := os.WriteFile(s.layoutPath, layoutData, 0644); err != nil {
return err
}
// modify the index file
idxFile, err := os.OpenFile(s.indexPath, os.O_RDWR|os.O_CREATE, 0644)
if err != nil {
return errors.Wrapf(err, "could not open %s", s.indexPath)
}
defer idxFile.Close()
var idx ocispecs.Index
idxData, err := io.ReadAll(idxFile)
if err != nil {
return errors.Wrapf(err, "could not read %s", s.indexPath)
}
if len(idxData) > 0 {
if err := json.Unmarshal(idxData, &idx); err != nil {
return errors.Wrapf(err, "could not unmarshal %s (%q)", s.indexPath, string(idxData))
}
}
setOCIIndexDefaults(&idx)
if err = insertDesc(&idx, desc, tag); err != nil {
return err
}
idxData, err = json.Marshal(idx)
if err != nil {
return err
}
if _, err = idxFile.WriteAt(idxData, 0); err != nil {
return errors.Wrapf(err, "could not write %s", s.indexPath)
}
if err = idxFile.Truncate(int64(len(idxData))); err != nil {
return errors.Wrapf(err, "could not truncate %s", s.indexPath)
}
return nil
}
func (s StoreIndex) Get(tag string) (*ocispecs.Descriptor, error) {
idx, err := s.Read()
if err != nil {
return nil, err
}
for _, m := range idx.Manifests {
if t, ok := m.Annotations[ocispecs.AnnotationRefName]; ok && t == tag {
return &m, nil
}
}
return nil, nil
}
func (s StoreIndex) GetSingle() (*ocispecs.Descriptor, error) {
idx, err := s.Read()
if err != nil {
return nil, err
}
if len(idx.Manifests) == 1 {
return &idx.Manifests[0], nil
}
return nil, nil
}
// setOCIIndexDefaults updates zero values in index to their default values.
func setOCIIndexDefaults(index *ocispecs.Index) {
if index == nil {
return
}
if index.SchemaVersion == 0 {
index.SchemaVersion = 2
}
if index.MediaType == "" {
index.MediaType = ocispecs.MediaTypeImageIndex
}
}
// insertDesc puts desc to index with tag.
// Existing manifests with the same tag will be removed from the index.
func insertDesc(index *ocispecs.Index, desc ocispecs.Descriptor, tag string) error {
if index == nil {
return nil
}
if tag != "" {
if desc.Annotations == nil {
desc.Annotations = make(map[string]string)
}
desc.Annotations[ocispecs.AnnotationRefName] = tag
// remove existing manifests with the same tag
var manifests []ocispecs.Descriptor
for _, m := range index.Manifests {
if m.Annotations[ocispecs.AnnotationRefName] != tag {
manifests = append(manifests, m)
}
}
index.Manifests = manifests
}
index.Manifests = append(index.Manifests, desc)
return nil
}
|
