Function Pull

pkg/imgutil/pull/pull.go:52–102

Pull loads all resources into the content store and returns the image

(ctx context.Context, client *containerd.Client, ref string, config *Config)

// Pull loads all resources into the content store and returns the image
func Pull(ctx context.Context, client *containerd.Client, ref string, config *Config) (containerd.Image, error) {
	ongoing := jobs.New(ref)

	pctx, stopProgress := context.WithCancel(ctx)
	progress := make(chan struct{})

	go func() {
		if config.ProgressOutput != nil {
			// no progress bar, because it hides some debug logs
			jobs.ShowProgress(pctx, ongoing, client.ContentStore(), config.ProgressOutput)
		}
		close(progress)
	}()

	h := images.HandlerFunc(func(ctx context.Context, desc ocispec.Descriptor) ([]ocispec.Descriptor, error) {
		if desc.MediaType != images.MediaTypeDockerSchema1Manifest {
			ongoing.Add(desc)
		}
		return nil, nil
	})

	log.G(pctx).WithField("image", ref).Debug("fetching")
	platformMC := platformutil.NewMatchComparerFromOCISpecPlatformSlice(config.Platforms)
	opts := []containerd.RemoteOpt{
		containerd.WithResolver(config.Resolver),
		containerd.WithImageHandler(h),
		containerd.WithPlatformMatcher(platformMC),
	}
	opts = append(opts, config.RemoteOpts...)

	var (
		img containerd.Image
		err error
	)
	if len(config.Platforms) == 1 {
		// client.Pull is for single-platform (w/ unpacking)
		img, err = client.Pull(pctx, ref, opts...)
	} else {
		// client.Fetch is for multi-platform (w/o unpacking)
		var imagesImg images.Image
		imagesImg, err = client.Fetch(pctx, ref, opts...)
		img = containerd.NewImageWithPlatform(client, imagesImg, platformMC)
	}
	stopProgress()
	if err != nil {
		return nil, err
	}

	<-progress
	return img, nil
}