forked from containerd/containerd
-
Notifications
You must be signed in to change notification settings - Fork 1
/
mediatypes.go
126 lines (112 loc) · 4.75 KB
/
mediatypes.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
/*
Copyright The containerd Authors.
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 images
import (
"context"
"sort"
"strings"
"github.com/containerd/containerd/errdefs"
ocispec "github.com/opencontainers/image-spec/specs-go/v1"
)
// mediatype definitions for image components handled in containerd.
//
// oci components are generally referenced directly, although we may centralize
// here for clarity.
const (
MediaTypeDockerSchema2Layer = "application/vnd.docker.image.rootfs.diff.tar"
MediaTypeDockerSchema2LayerForeign = "application/vnd.docker.image.rootfs.foreign.diff.tar"
MediaTypeDockerSchema2LayerGzip = "application/vnd.docker.image.rootfs.diff.tar.gzip"
MediaTypeDockerSchema2LayerForeignGzip = "application/vnd.docker.image.rootfs.foreign.diff.tar.gzip"
MediaTypeDockerSchema2Config = "application/vnd.docker.container.image.v1+json"
MediaTypeDockerSchema2Manifest = "application/vnd.docker.distribution.manifest.v2+json"
MediaTypeDockerSchema2ManifestList = "application/vnd.docker.distribution.manifest.list.v2+json"
// Checkpoint/Restore Media Types
MediaTypeContainerd1Checkpoint = "application/vnd.containerd.container.criu.checkpoint.criu.tar"
MediaTypeContainerd1CheckpointPreDump = "application/vnd.containerd.container.criu.checkpoint.predump.tar"
MediaTypeContainerd1Resource = "application/vnd.containerd.container.resource.tar"
MediaTypeContainerd1RW = "application/vnd.containerd.container.rw.tar"
MediaTypeContainerd1CheckpointConfig = "application/vnd.containerd.container.checkpoint.config.v1+proto"
MediaTypeContainerd1CheckpointOptions = "application/vnd.containerd.container.checkpoint.options.v1+proto"
MediaTypeContainerd1CheckpointRuntimeName = "application/vnd.containerd.container.checkpoint.runtime.name"
MediaTypeContainerd1CheckpointRuntimeOptions = "application/vnd.containerd.container.checkpoint.runtime.options+proto"
// Legacy Docker schema1 manifest
MediaTypeDockerSchema1Manifest = "application/vnd.docker.distribution.manifest.v1+prettyjws"
)
// DiffCompression returns the compression as defined by the layer diff media
// type. For Docker media types without compression, "unknown" is returned to
// indicate that the media type may be compressed. If the media type is not
// recognized as a layer diff, then it returns errdefs.ErrNotImplemented
func DiffCompression(ctx context.Context, mediaType string) (string, error) {
base, ext := parseMediaTypes(mediaType)
switch base {
case MediaTypeDockerSchema2Layer, MediaTypeDockerSchema2LayerForeign:
if len(ext) > 0 {
// Type is wrapped
return "", nil
}
// These media types may have been compressed but failed to
// use the correct media type. The decompression function
// should detect and handle this case.
return "unknown", nil
case MediaTypeDockerSchema2LayerGzip, MediaTypeDockerSchema2LayerForeignGzip:
if len(ext) > 0 {
// Type is wrapped
return "", nil
}
return "gzip", nil
case ocispec.MediaTypeImageLayer, ocispec.MediaTypeImageLayerNonDistributable:
if len(ext) > 0 {
switch ext[len(ext)-1] {
case "gzip":
return "gzip", nil
}
}
return "", nil
default:
return "", errdefs.ErrNotImplemented
}
}
// parseMediaTypes splits the media type into the base type and
// an array of sorted extensions
func parseMediaTypes(mt string) (string, []string) {
if mt == "" {
return "", []string{}
}
s := strings.Split(mt, "+")
ext := s[1:]
sort.Strings(ext)
return s[0], ext
}
// IsLayerTypes returns true if the media type is a layer
func IsLayerType(mt string) bool {
if strings.HasPrefix(mt, "application/vnd.oci.image.layer.") {
return true
}
// Parse Docker media types, strip off any + suffixes first
base, _ := parseMediaTypes(mt)
switch base {
case MediaTypeDockerSchema2Layer, MediaTypeDockerSchema2LayerGzip,
MediaTypeDockerSchema2LayerForeign, MediaTypeDockerSchema2LayerForeignGzip:
return true
}
return false
}
// IsKnownConfig returns true if the media type is a known config type
func IsKnownConfig(mt string) bool {
switch mt {
case MediaTypeDockerSchema2Config, ocispec.MediaTypeImageConfig,
MediaTypeContainerd1Checkpoint, MediaTypeContainerd1CheckpointConfig:
return true
}
return false
}