5ca3ac65c4
Go example:
```go
opts := []converter.Opt{
// convert Docker media types to OCI ones
converter.WithDocker2OCI(true),
// convert tar.gz layers to uncompressed tar layers
converter.WithLayerConvertFunc(uncompress.LayerConvertFunc),
}
srcRef := "example.com/foo:orig"
dstRef := "example.com/foo:converted"
dstImg, err = converter.Convert(ctx, client, dstRef, srcRef, opts...)
fmt.Println(dstImg.Target)
```
ctr example: `ctr images convert --oci --uncompress example.com/foo:orig example.com/foo:converted`
Go test: `go test -exec sudo -test.root -test.run TestConvert`
The implementation is from https://github.com/containerd/stargz-snapshotter/pull/224,
but eStargz-specific functions are not included in this PR.
eStargz converter can be specified by importing `estargz` package and using `WithLayerConvertFunc(estargz.LayerConvertFunc)` option.
This converter interface will be potentially useful for converting zstd and ocicrypt layers as well.
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
127 lines
3.2 KiB
Go
127 lines
3.2 KiB
Go
/*
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Copyright The containerd Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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// Package converter provides image converter
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package converter
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import (
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"context"
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"github.com/containerd/containerd/content"
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"github.com/containerd/containerd/images"
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"github.com/containerd/containerd/leases"
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"github.com/containerd/containerd/platforms"
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)
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type convertOpts struct {
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layerConvertFunc ConvertFunc
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docker2oci bool
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indexConvertFunc ConvertFunc
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platformMC platforms.MatchComparer
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}
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// Opt is an option for Convert()
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type Opt func(*convertOpts) error
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// WithLayerConvertFunc specifies the function that converts layers.
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func WithLayerConvertFunc(fn ConvertFunc) Opt {
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return func(copts *convertOpts) error {
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copts.layerConvertFunc = fn
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return nil
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}
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}
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// WithDockerToOCI converts Docker media types into OCI ones.
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func WithDockerToOCI(v bool) Opt {
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return func(copts *convertOpts) error {
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copts.docker2oci = true
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return nil
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}
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}
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// WithPlatform specifies the platform.
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// Defaults to all platforms.
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func WithPlatform(p platforms.MatchComparer) Opt {
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return func(copts *convertOpts) error {
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copts.platformMC = p
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return nil
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}
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}
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// WithIndexConvertFunc specifies the function that converts manifests and index (manifest lists).
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// Defaults to DefaultIndexConvertFunc.
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func WithIndexConvertFunc(fn ConvertFunc) Opt {
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return func(copts *convertOpts) error {
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copts.indexConvertFunc = fn
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return nil
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}
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}
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// Client is implemented by *containerd.Client .
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type Client interface {
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WithLease(ctx context.Context, opts ...leases.Opt) (context.Context, func(context.Context) error, error)
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ContentStore() content.Store
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ImageService() images.Store
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}
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// Convert converts an image.
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func Convert(ctx context.Context, client Client, dstRef, srcRef string, opts ...Opt) (*images.Image, error) {
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var copts convertOpts
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for _, o := range opts {
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if err := o(&copts); err != nil {
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return nil, err
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}
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}
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if copts.platformMC == nil {
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copts.platformMC = platforms.All
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}
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if copts.indexConvertFunc == nil {
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copts.indexConvertFunc = DefaultIndexConvertFunc(copts.layerConvertFunc, copts.docker2oci, copts.platformMC)
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}
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ctx, done, err := client.WithLease(ctx)
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if err != nil {
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return nil, err
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}
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defer done(ctx)
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cs := client.ContentStore()
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is := client.ImageService()
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srcImg, err := is.Get(ctx, srcRef)
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if err != nil {
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return nil, err
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}
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dstDesc, err := copts.indexConvertFunc(ctx, cs, srcImg.Target)
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if err != nil {
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return nil, err
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}
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dstImg := srcImg
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dstImg.Name = dstRef
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if dstDesc != nil {
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dstImg.Target = *dstDesc
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}
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var res images.Image
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if dstRef != srcRef {
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_ = is.Delete(ctx, dstRef)
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res, err = is.Create(ctx, dstImg)
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} else {
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res, err = is.Update(ctx, dstImg)
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}
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return &res, err
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}
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