 5ca3ac65c4
			
		
	
	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>
		
	
		
			
				
	
	
		
			109 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			109 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| /*
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|    Copyright The containerd Authors.
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| 
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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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| 
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|        http://www.apache.org/licenses/LICENSE-2.0
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| 
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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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| 
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| package images
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| 
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| import (
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| 	"fmt"
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| 
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| 	"github.com/containerd/containerd/cmd/ctr/commands"
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| 	"github.com/containerd/containerd/images/converter"
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| 	"github.com/containerd/containerd/images/converter/uncompress"
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| 	"github.com/containerd/containerd/platforms"
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| 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
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| 	"github.com/pkg/errors"
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| 	"github.com/urfave/cli"
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| )
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| 
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| var convertCommand = cli.Command{
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| 	Name:      "convert",
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| 	Usage:     "convert an image",
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| 	ArgsUsage: "[flags] <source_ref> <target_ref>",
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| 	Description: `Convert an image format.
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| 
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| e.g., 'ctr convert --uncompress --oci example.com/foo:orig example.com/foo:converted'
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| 
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| Use '--platform' to define the output platform.
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| When '--all-platforms' is given all images in a manifest list must be available.
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| `,
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| 	Flags: []cli.Flag{
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| 		// generic flags
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| 		cli.BoolFlag{
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| 			Name:  "uncompress",
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| 			Usage: "convert tar.gz layers to uncompressed tar layers",
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| 		},
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| 		cli.BoolFlag{
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| 			Name:  "oci",
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| 			Usage: "convert Docker media types to OCI media types",
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| 		},
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| 		// platform flags
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| 		cli.StringSliceFlag{
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| 			Name:  "platform",
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| 			Usage: "Pull content from a specific platform",
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| 			Value: &cli.StringSlice{},
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| 		},
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| 		cli.BoolFlag{
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| 			Name:  "all-platforms",
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| 			Usage: "exports content from all platforms",
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| 		},
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| 	},
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| 	Action: func(context *cli.Context) error {
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| 		var convertOpts []converter.Opt
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| 		srcRef := context.Args().Get(0)
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| 		targetRef := context.Args().Get(1)
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| 		if srcRef == "" || targetRef == "" {
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| 			return errors.New("src and target image need to be specified")
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| 		}
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| 
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| 		if !context.Bool("all-platforms") {
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| 			if pss := context.StringSlice("platform"); len(pss) > 0 {
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| 				var all []ocispec.Platform
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| 				for _, ps := range pss {
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| 					p, err := platforms.Parse(ps)
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| 					if err != nil {
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| 						return errors.Wrapf(err, "invalid platform %q", ps)
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| 					}
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| 					all = append(all, p)
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| 				}
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| 				convertOpts = append(convertOpts, converter.WithPlatform(platforms.Ordered(all...)))
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| 			} else {
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| 				convertOpts = append(convertOpts, converter.WithPlatform(platforms.DefaultStrict()))
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| 			}
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| 		}
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| 
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| 		if context.Bool("uncompress") {
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| 			convertOpts = append(convertOpts, converter.WithLayerConvertFunc(uncompress.LayerConvertFunc))
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| 		}
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| 
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| 		if context.Bool("oci") {
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| 			convertOpts = append(convertOpts, converter.WithDockerToOCI(true))
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| 		}
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| 
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| 		client, ctx, cancel, err := commands.NewClient(context)
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| 		if err != nil {
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| 			return err
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| 		}
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| 		defer cancel()
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| 
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| 		newImg, err := converter.Convert(ctx, client, targetRef, srcRef, convertOpts...)
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| 		if err != nil {
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| 			return err
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| 		}
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| 		fmt.Fprintln(context.App.Writer, newImg.Target.Digest.String())
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| 		return nil
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| 	},
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| }
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