Function generateBuildctlArgs

pkg/cmd/builder/build.go:207–491

(ctx context.Context, client *containerd.Client, options types.BuilderBuildOptions)

}

func generateBuildctlArgs(ctx context.Context, client *containerd.Client, options types.BuilderBuildOptions) (buildCtlBinary string,
	buildctlArgs []string, needsLoading bool, metaFile string, tags []string, cleanup func(), err error) {

	buildctlBinary, err := buildkitutil.BuildctlBinary()
	if err != nil {
		return "", nil, false, "", nil, nil, err
	}

	output := options.Output
	if output == "" {
		info, err := client.Server(ctx)
		if err != nil {
			return "", nil, false, "", nil, nil, err
		}
		sharable, err := isImageSharable(options.BuildKitHost, options.GOptions.Namespace, info.UUID, options.GOptions.Snapshotter, options.Platform)
		if err != nil {
			return "", nil, false, "", nil, nil, err
		}
		if sharable {
			output = "type=image,unpack=true" // ensure the target stage is unlazied (needed for any snapshotters)
		} else {
			output = "type=docker"
			if len(options.Platform) > 1 {
				// For avoiding `error: failed to solve: docker exporter does not currently support exporting manifest lists`
				// TODO: consider using type=oci for single-options.Platform build too
				output = "type=oci"
			}
			needsLoading = true
		}
	} else {
		if !strings.Contains(output, "type=") {
			// should accept --output <DIR> as an alias of --output
			// type=local,dest=<DIR>
			output = fmt.Sprintf("type=local,dest=%s", output)
		}
		if strings.Contains(output, "type=docker") || strings.Contains(output, "type=oci") {
			if !strings.Contains(output, "dest=") {
				needsLoading = true
			}
		}
	}
	if tags = strutil.DedupeStrSlice(options.Tag); len(tags) > 0 {
		ref := tags[0]
		parsedReference, err := referenceutil.Parse(ref)
		if err != nil {
			return "", nil, false, "", nil, nil, err
		}
		output += ",name=" + parsedReference.String()

		// pick the first tag and add it to output
		for idx, tag := range tags {
			parsedReference, err = referenceutil.Parse(tag)
			if err != nil {
				return "", nil, false, "", nil, nil, err
			}
			tags[idx] = parsedReference.String()
		}
	} else if len(tags) == 0 {