podman

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package ocipull
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import (
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	"context"
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	"encoding/json"
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	"errors"
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	"fmt"
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	"github.com/containers/image/v5/manifest"
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	"github.com/containers/image/v5/oci/layout"
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	"github.com/containers/image/v5/types"
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	"github.com/opencontainers/go-digest"
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	specV1 "github.com/opencontainers/image-spec/specs-go/v1"
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	"github.com/sirupsen/logrus"
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)
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func GetLocalBlob(ctx context.Context, path string) (*types.BlobInfo, error) {
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	ociRef, err := layout.ParseReference(path)
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	if err != nil {
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		return nil, err
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	}
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	img, err := ociRef.NewImage(ctx, &types.SystemContext{})
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	if err != nil {
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		return nil, err
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	}
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	b, _, err := img.Manifest(ctx)
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	if err != nil {
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		return nil, err
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	}
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	localManifest := specV1.Manifest{}
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	if err := json.Unmarshal(b, &localManifest); err != nil {
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		return nil, err
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	}
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	blobs := img.LayerInfos()
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	if err != nil {
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		return nil, err
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	}
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	if len(blobs) != 1 {
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		return nil, errors.New("invalid disk image")
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	}
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	fmt.Println(blobs[0].Digest.Hex())
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	return &blobs[0], nil
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}
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func GetDiskArtifactReference(ctx context.Context, imgSrc types.ImageSource, opts *DiskArtifactOpts) (digest.Digest, error) {
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	rawMannyFest, mannyType, err := imgSrc.GetManifest(ctx, nil)
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	if err != nil {
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		return "", err
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	}
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	if !manifest.MIMETypeIsMultiImage(mannyType) { // if not true
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		return "", fmt.Errorf("wrong manifest type for disk artifact: %s", mannyType)
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	}
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	mannyFestList, err := manifest.ListFromBlob(rawMannyFest, mannyType)
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	if err != nil {
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		return "", fmt.Errorf("failed to parse manifest list from blob: %q", err)
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	}
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	var (
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		artifactDigest digest.Digest
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	)
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	for _, d := range mannyFestList.Instances() {
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		bar, err := mannyFestList.Instance(d)
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		if err != nil {
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			return "", err
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		}
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		val, ok := bar.ReadOnly.Annotations["disktype"]
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		if !ok { // quick exit, no type match
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			continue
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		}
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		// wrong arch
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		if bar.ReadOnly.Platform.Architecture != opts.arch {
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			continue
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		}
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		// wrong os
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		if bar.ReadOnly.Platform.OS != opts.os {
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			continue
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		}
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		// wrong disktype
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		if val != opts.diskType {
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			continue
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		}
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		// ok, we have a match
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		artifactDigest = d
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		logrus.Debugf("found image in digest: %q", artifactDigest.String())
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		break
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	}
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	if artifactDigest == "" {
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		return "", fmt.Errorf("no valid disk artifact found")
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	}
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	v1RawMannyfest, _, err := imgSrc.GetManifest(ctx, &artifactDigest)
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	if err != nil {
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		return "", err
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	}
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	v1MannyFest := specV1.Manifest{}
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	if err := json.Unmarshal(v1RawMannyfest, &v1MannyFest); err != nil {
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		return "", err
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	}
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	if layerLen := len(v1MannyFest.Layers); layerLen > 1 {
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		return "", fmt.Errorf("podman-machine images should only have 1 layer: %d found", layerLen)
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	}
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	// podman-machine-images should have a original file name
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	// stored in the annotations under org.opencontainers.image.title
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	// i.e. fedora-coreos-39.20240128.2.2-qemu.x86_64.qcow2.xz
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	originalFileName, ok := v1MannyFest.Layers[0].Annotations["org.opencontainers.image.title"]
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	if !ok {
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		return "", fmt.Errorf("unable to determine original artifact name: missing required annotation 'org.opencontainers.image.title'")
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	}
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	logrus.Debugf("original artifact file name: %s", originalFileName)
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	return artifactDigest, err
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}
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