Remove aufs snapshotter (deprecated since v1.5)

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

diff/apply/apply_linux.go

@@ -51,22 +51,6 @@ func apply(ctx context.Context, mounts []mount.Mount, r io.Reader) error {
 		}
 		_, err = archive.Apply(ctx, path, r, opts...)
 		return err
-	case len(mounts) == 1 && mounts[0].Type == "aufs":
-		path, parents, err := getAufsPath(mounts[0].Options)
-		if err != nil {
-			if errdefs.IsInvalidArgument(err) {
-				break
-			}
-			return err
-		}
-		opts := []archive.ApplyOpt{
-			archive.WithConvertWhiteout(archive.AufsConvertWhiteout),
-		}
-		if len(parents) > 0 {
-			opts = append(opts, archive.WithParents(parents))
-		}
-		_, err = archive.Apply(ctx, path, r, opts...)
-		return err
 	}
 	return mount.WithTempMount(ctx, mounts, func(root string) error {
 		_, err := archive.Apply(ctx, root, r)
@@ -91,42 +75,3 @@ func getOverlayPath(options []string) (upper string, lower []string, err error)
 
 	return
 }
-
-// getAufsPath handles options as given by the containerd aufs package only,
-// formatted as "br:<upper>=rw[:<lower>=ro+wh]*"
-func getAufsPath(options []string) (upper string, lower []string, err error) {
-	const (
-		sep      = ":"
-		brPrefix = "br:"
-		rwSuffix = "=rw"
-		roSuffix = "=ro+wh"
-	)
-	for _, o := range options {
-		if strings.HasPrefix(o, brPrefix) {
-			o = strings.TrimPrefix(o, brPrefix)
-		} else {
-			continue
-		}
-
-		for _, b := range strings.Split(o, sep) {
-			if strings.HasSuffix(b, rwSuffix) {
-				if upper != "" {
-					return "", nil, fmt.Errorf("multiple rw branch found: %w", errdefs.ErrInvalidArgument)
-				}
-				upper = strings.TrimSuffix(b, rwSuffix)
-			} else if strings.HasSuffix(b, roSuffix) {
-				if upper == "" {
-					return "", nil, fmt.Errorf("rw branch be first: %w", errdefs.ErrInvalidArgument)
-				}
-				lower = append(lower, strings.TrimSuffix(b, roSuffix))
-			} else {
-				return "", nil, fmt.Errorf("unhandled aufs suffix: %w", errdefs.ErrInvalidArgument)
-			}
-
-		}
-	}
-	if upper == "" {
-		return "", nil, fmt.Errorf("rw branch not found: %w", errdefs.ErrInvalidArgument)
-	}
-	return
-}