Function resolveSnapshotOptions

client/snapshotter_opts_unix.go:62–136

(ctx context.Context, client *Client, snapshotterName string, snapshotter snapshots.Snapshotter, parent string, opts ...snapshots.Opt)

}

func resolveSnapshotOptions(ctx context.Context, client *Client, snapshotterName string, snapshotter snapshots.Snapshotter, parent string, opts ...snapshots.Opt) (string, error) {
	capabs, err := client.GetSnapshotterCapabilities(ctx, snapshotterName)
	if err != nil {
		return "", err
	}

	if slices.Contains(capabs, capaRemapIDs) {
		// Snapshotter supports ID remapping, we don't need to do anything.
		return parent, nil
	}

	var local snapshots.Info
	for _, opt := range opts {
		opt(&local)
	}

	needsRemap := false
	var uidMapLabel, gidMapLabel string

	if value, ok := local.Labels[snapshots.LabelSnapshotUIDMapping]; ok {
		needsRemap = true
		uidMapLabel = value
	}
	if value, ok := local.Labels[snapshots.LabelSnapshotGIDMapping]; ok {
		needsRemap = true
		gidMapLabel = value
	}

	if !needsRemap {
		return parent, nil
	}

	capaOnlyRemap := false
	for _, capa := range capabs {
		if capa == capaOnlyRemapIDs {
			capaOnlyRemap = true
		}
	}

	if capaOnlyRemap {
		return "", fmt.Errorf("snapshotter %q doesn't support idmap mounts on this host, configure `slow_chown` to allow a slower and expensive fallback", snapshotterName)
	}

	rsn := remappedSnapshot{Parent: parent}
	if err = rsn.IDMap.Unmarshal(uidMapLabel, gidMapLabel); err != nil {
		return "", fmt.Errorf("failed to unmarshal uid/gid map snapshotter labels: %w", err)
	}

	if _, err := rsn.IDMap.RootPair(); err != nil {
		return "", fmt.Errorf("container UID/GID mapping entries of 0 are required but not found")
	}

	usernsID, err := rsn.ID()
	if err != nil {
		return "", fmt.Errorf("failed to remap snapshot: %w", err)
	}

	if _, err := snapshotter.Stat(ctx, usernsID); err == nil {