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
|
package image
import (
"context"
"encoding/json"
"fmt"
"io/ioutil"
"github.com/containers/image/v5/docker/reference"
"github.com/containers/image/v5/manifest"
"github.com/containers/image/v5/pkg/blobinfocache/none"
"github.com/containers/image/v5/types"
"github.com/opencontainers/go-digest"
imgspecv1 "github.com/opencontainers/image-spec/specs-go/v1"
"github.com/pkg/errors"
)
type manifestOCI1 struct {
src types.ImageSource // May be nil if configBlob is not nil
configBlob []byte // If set, corresponds to contents of m.Config.
m *manifest.OCI1
}
func manifestOCI1FromManifest(src types.ImageSource, manifestBlob []byte) (genericManifest, error) {
m, err := manifest.OCI1FromManifest(manifestBlob)
if err != nil {
return nil, err
}
return &manifestOCI1{
src: src,
m: m,
}, nil
}
// manifestOCI1FromComponents builds a new manifestOCI1 from the supplied data:
func manifestOCI1FromComponents(config imgspecv1.Descriptor, src types.ImageSource, configBlob []byte, layers []imgspecv1.Descriptor) genericManifest {
return &manifestOCI1{
src: src,
configBlob: configBlob,
m: manifest.OCI1FromComponents(config, layers),
}
}
func (m *manifestOCI1) serialize() ([]byte, error) {
return m.m.Serialize()
}
func (m *manifestOCI1) manifestMIMEType() string {
return imgspecv1.MediaTypeImageManifest
}
// ConfigInfo returns a complete BlobInfo for the separate config object, or a BlobInfo{Digest:""} if there isn't a separate object.
// Note that the config object may not exist in the underlying storage in the return value of UpdatedImage! Use ConfigBlob() below.
func (m *manifestOCI1) ConfigInfo() types.BlobInfo {
return m.m.ConfigInfo()
}
// ConfigBlob returns the blob described by ConfigInfo, iff ConfigInfo().Digest != ""; nil otherwise.
// The result is cached; it is OK to call this however often you need.
func (m *manifestOCI1) ConfigBlob(ctx context.Context) ([]byte, error) {
if m.configBlob == nil {
if m.src == nil {
return nil, errors.Errorf("Internal error: neither src nor configBlob set in manifestOCI1")
}
stream, _, err := m.src.GetBlob(ctx, manifest.BlobInfoFromOCI1Descriptor(m.m.Config), none.NoCache)
if err != nil {
return nil, err
}
defer stream.Close()
blob, err := ioutil.ReadAll(stream)
if err != nil {
return nil, err
}
computedDigest := digest.FromBytes(blob)
if computedDigest != m.m.Config.Digest {
return nil, errors.Errorf("Download config.json digest %s does not match expected %s", computedDigest, m.m.Config.Digest)
}
m.configBlob = blob
}
return m.configBlob, nil
}
// OCIConfig returns the image configuration as per OCI v1 image-spec. Information about
// layers in the resulting configuration isn't guaranteed to be returned to due how
// old image manifests work (docker v2s1 especially).
func (m *manifestOCI1) OCIConfig(ctx context.Context) (*imgspecv1.Image, error) {
cb, err := m.ConfigBlob(ctx)
if err != nil {
return nil, err
}
configOCI := &imgspecv1.Image{}
if err := json.Unmarshal(cb, configOCI); err != nil {
return nil, err
}
return configOCI, nil
}
// LayerInfos returns a list of BlobInfos of layers referenced by this image, in order (the root layer first, and then successive layered layers).
// The Digest field is guaranteed to be provided; Size may be -1.
// WARNING: The list may contain duplicates, and they are semantically relevant.
func (m *manifestOCI1) LayerInfos() []types.BlobInfo {
return manifestLayerInfosToBlobInfos(m.m.LayerInfos())
}
// EmbeddedDockerReferenceConflicts whether a Docker reference embedded in the manifest, if any, conflicts with destination ref.
// It returns false if the manifest does not embed a Docker reference.
// (This embedding unfortunately happens for Docker schema1, please do not add support for this in any new formats.)
func (m *manifestOCI1) EmbeddedDockerReferenceConflicts(ref reference.Named) bool {
return false
}
// Inspect returns various information for (skopeo inspect) parsed from the manifest and configuration.
func (m *manifestOCI1) Inspect(ctx context.Context) (*types.ImageInspectInfo, error) {
getter := func(info types.BlobInfo) ([]byte, error) {
if info.Digest != m.ConfigInfo().Digest {
// Shouldn't ever happen
return nil, errors.New("asked for a different config blob")
}
config, err := m.ConfigBlob(ctx)
if err != nil {
return nil, err
}
return config, nil
}
return m.m.Inspect(getter)
}
// UpdatedImageNeedsLayerDiffIDs returns true iff UpdatedImage(options) needs InformationOnly.LayerDiffIDs.
// This is a horribly specific interface, but computing InformationOnly.LayerDiffIDs can be very expensive to compute
// (most importantly it forces us to download the full layers even if they are already present at the destination).
func (m *manifestOCI1) UpdatedImageNeedsLayerDiffIDs(options types.ManifestUpdateOptions) bool {
return false
}
// UpdatedImage returns a types.Image modified according to options.
// This does not change the state of the original Image object.
func (m *manifestOCI1) UpdatedImage(ctx context.Context, options types.ManifestUpdateOptions) (types.Image, error) {
copy := manifestOCI1{ // NOTE: This is not a deep copy, it still shares slices etc.
src: m.src,
configBlob: m.configBlob,
m: manifest.OCI1Clone(m.m),
}
if options.LayerInfos != nil {
if err := copy.m.UpdateLayerInfos(options.LayerInfos); err != nil {
return nil, err
}
}
// Ignore options.EmbeddedDockerReference: it may be set when converting from schema1, but we really don't care.
switch options.ManifestMIMEType {
case "": // No conversion, OK
case manifest.DockerV2Schema1MediaType, manifest.DockerV2Schema1SignedMediaType:
// We can't directly convert to V1, but we can transitively convert via a V2 image
m2, err := copy.convertToManifestSchema2()
if err != nil {
return nil, err
}
return m2.UpdatedImage(ctx, types.ManifestUpdateOptions{
ManifestMIMEType: options.ManifestMIMEType,
InformationOnly: options.InformationOnly,
})
case manifest.DockerV2Schema2MediaType:
return copy.convertToManifestSchema2()
default:
return nil, errors.Errorf("Conversion of image manifest from %s to %s is not implemented", imgspecv1.MediaTypeImageManifest, options.ManifestMIMEType)
}
return memoryImageFromManifest(©), nil
}
func schema2DescriptorFromOCI1Descriptor(d imgspecv1.Descriptor) manifest.Schema2Descriptor {
return manifest.Schema2Descriptor{
MediaType: d.MediaType,
Size: d.Size,
Digest: d.Digest,
URLs: d.URLs,
}
}
func (m *manifestOCI1) convertToManifestSchema2() (types.Image, error) {
// Create a copy of the descriptor.
config := schema2DescriptorFromOCI1Descriptor(m.m.Config)
// The only difference between OCI and DockerSchema2 is the mediatypes. The
// media type of the manifest is handled by manifestSchema2FromComponents.
config.MediaType = manifest.DockerV2Schema2ConfigMediaType
layers := make([]manifest.Schema2Descriptor, len(m.m.Layers))
for idx := range layers {
layers[idx] = schema2DescriptorFromOCI1Descriptor(m.m.Layers[idx])
switch layers[idx].MediaType {
case imgspecv1.MediaTypeImageLayerNonDistributable:
layers[idx].MediaType = manifest.DockerV2Schema2ForeignLayerMediaType
case imgspecv1.MediaTypeImageLayerNonDistributableGzip:
layers[idx].MediaType = manifest.DockerV2Schema2ForeignLayerMediaTypeGzip
case imgspecv1.MediaTypeImageLayerNonDistributableZstd:
return nil, fmt.Errorf("Error during manifest conversion: %q: zstd compression is not supported for docker images", layers[idx].MediaType)
case imgspecv1.MediaTypeImageLayer:
layers[idx].MediaType = manifest.DockerV2SchemaLayerMediaTypeUncompressed
case imgspecv1.MediaTypeImageLayerGzip:
layers[idx].MediaType = manifest.DockerV2Schema2LayerMediaType
case imgspecv1.MediaTypeImageLayerZstd:
return nil, fmt.Errorf("Error during manifest conversion: %q: zstd compression is not supported for docker images", layers[idx].MediaType)
default:
return nil, fmt.Errorf("Unknown media type during manifest conversion: %q", layers[idx].MediaType)
}
}
// Rather than copying the ConfigBlob now, we just pass m.src to the
// translated manifest, since the only difference is the mediatype of
// descriptors there is no change to any blob stored in m.src.
m1 := manifestSchema2FromComponents(config, m.src, nil, layers)
return memoryImageFromManifest(m1), nil
}
|
