forked from TrueCloudLab/distribution
2ff77c00ba
Add schema2 manifest implementation. Add a schema2 builder that creates a schema2 manifest from descriptors and a configuration. It will add the configuration to the blob store if necessary. Rename the original schema1 manifest builder to ReferenceBuilder, and create a ConfigBuilder variant that can build a schema1 manifest from an image configuration and set of descriptors. This will be used to translate schema2 manifests to the schema1 format for backward compatibliity, by adding the descriptors from the existing schema2 manifest to the schema1 builder. It will also be used by engine-side push code to create schema1 manifests from the new-style image configration, when necessary to push a schema1 manifest. Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
78 lines
2 KiB
Go
78 lines
2 KiB
Go
package schema2
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import (
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"github.com/docker/distribution"
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"github.com/docker/distribution/context"
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"github.com/docker/distribution/digest"
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"github.com/docker/distribution/manifest"
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)
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// builder is a type for constructing manifests.
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type builder struct {
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// bs is a BlobService used to publish the configuration blob.
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bs distribution.BlobService
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// configJSON references
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configJSON []byte
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// layers is a list of layer descriptors that gets built by successive
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// calls to AppendReference.
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layers []distribution.Descriptor
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}
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// NewManifestBuilder is used to build new manifests for the current schema
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// version. It takes a BlobService so it can publish the configuration blob
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// as part of the Build process.
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func NewManifestBuilder(bs distribution.BlobService, configJSON []byte) distribution.ManifestBuilder {
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mb := &builder{
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bs: bs,
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configJSON: make([]byte, len(configJSON)),
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}
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copy(mb.configJSON, configJSON)
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return mb
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}
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// Build produces a final manifest from the given references.
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func (mb *builder) Build(ctx context.Context) (distribution.Manifest, error) {
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m := Manifest{
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Versioned: manifest.Versioned{
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SchemaVersion: 2,
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},
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MediaType: MediaTypeManifest,
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Layers: make([]distribution.Descriptor, len(mb.layers)),
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}
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copy(m.Layers, mb.layers)
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configDigest := digest.FromBytes(mb.configJSON)
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var err error
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m.Config, err = mb.bs.Stat(ctx, configDigest)
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switch err {
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case nil:
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return FromStruct(m)
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case distribution.ErrBlobUnknown:
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// nop
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default:
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return nil, err
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}
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// Add config to the blob store
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m.Config, err = mb.bs.Put(ctx, MediaTypeConfig, mb.configJSON)
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if err != nil {
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return nil, err
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}
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return FromStruct(m)
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}
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// AppendReference adds a reference to the current ManifestBuilder.
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func (mb *builder) AppendReference(d distribution.Describable) error {
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mb.layers = append(mb.layers, d.Descriptor())
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return nil
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}
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// References returns the current references added to this builder.
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func (mb *builder) References() []distribution.Descriptor {
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return mb.layers
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}
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