Support applying with parent directories

Signed-off-by: Derek McGowan <derek@mcgstyle.net>

archive/tar_linux_test.go

@@ -0,0 +1,183 @@
+// +build linux
+
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package archive
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/containerd/containerd/log/logtest"
+	"github.com/containerd/containerd/mount"
+	"github.com/containerd/containerd/pkg/testutil"
+	"github.com/containerd/containerd/snapshots/overlay"
+	"github.com/containerd/continuity/fs"
+	"github.com/containerd/continuity/fs/fstest"
+	"github.com/pkg/errors"
+)
+
+func TestOverlayApply(t *testing.T) {
+	testutil.RequiresRoot(t)
+
+	base, err := ioutil.TempDir("", "test-ovl-diff-apply-")
+	if err != nil {
+		t.Fatalf("unable to create temp dir: %+v", err)
+	}
+	defer os.RemoveAll(base)
+
+	if err := overlay.Supported(base); err != nil {
+		t.Skipf("skipping because overlay is not supported %v", err)
+	}
+	fstest.FSSuite(t, overlayDiffApplier{
+		tmp:  base,
+		diff: WriteDiff,
+		t:    t,
+	})
+}
+
+func TestOverlayApplyNoParents(t *testing.T) {
+	testutil.RequiresRoot(t)
+
+	base, err := ioutil.TempDir("", "test-ovl-diff-apply-")
+	if err != nil {
+		t.Fatalf("unable to create temp dir: %+v", err)
+	}
+	defer os.RemoveAll(base)
+
+	if err := overlay.Supported(base); err != nil {
+		t.Skipf("skipping because overlay is not supported %v", err)
+	}
+	fstest.FSSuite(t, overlayDiffApplier{
+		tmp: base,
+		diff: func(ctx context.Context, w io.Writer, a, b string) error {
+			cw := newChangeWriter(w, b)
+			cw.addedDirs = nil
+			err := fs.Changes(ctx, a, b, cw.HandleChange)
+			if err != nil {
+				return errors.Wrap(err, "failed to create diff tar stream")
+			}
+			return cw.Close()
+		},
+		t: t,
+	})
+}
+
+type overlayDiffApplier struct {
+	tmp  string
+	diff func(context.Context, io.Writer, string, string) error
+	t    *testing.T
+}
+
+type overlayContext struct {
+	merged  string
+	lowers  []string
+	mounted bool
+}
+
+type contextKey struct{}
+
+func (d overlayDiffApplier) TestContext(ctx context.Context) (context.Context, func(), error) {
+	merged, err := ioutil.TempDir(d.tmp, "merged")
+	if err != nil {
+		return ctx, nil, errors.Wrap(err, "failed to make merged dir")
+	}
+
+	oc := &overlayContext{
+		merged: merged,
+	}
+
+	ctx = logtest.WithT(ctx, d.t)
+
+	return context.WithValue(ctx, contextKey{}, oc), func() {
+		if oc.mounted {
+			mount.Unmount(oc.merged, 0)
+		}
+	}, nil
+}
+
+func (d overlayDiffApplier) Apply(ctx context.Context, a fstest.Applier) (string, func(), error) {
+	oc := ctx.Value(contextKey{}).(*overlayContext)
+
+	applyCopy, err := ioutil.TempDir(d.tmp, "apply-copy-")
+	if err != nil {
+		return "", nil, errors.Wrap(err, "failed to create temp dir")
+	}
+	defer os.RemoveAll(applyCopy)
+
+	base := oc.merged
+	if len(oc.lowers) == 1 {
+		base = oc.lowers[0]
+	}
+
+	if err = fs.CopyDir(applyCopy, base); err != nil {
+		return "", nil, errors.Wrap(err, "failed to copy base")
+	}
+
+	if err := a.Apply(applyCopy); err != nil {
+		return "", nil, errors.Wrap(err, "failed to apply changes to copy of base")
+	}
+
+	buf := bytes.NewBuffer(nil)
+
+	if err := d.diff(ctx, buf, base, applyCopy); err != nil {
+		return "", nil, errors.Wrap(err, "failed to create diff")
+	}
+
+	if oc.mounted {
+		if err := mount.Unmount(oc.merged, 0); err != nil {
+			return "", nil, errors.Wrap(err, "failed to unmount")
+		}
+		oc.mounted = false
+	}
+
+	next, err := ioutil.TempDir(d.tmp, "lower-")
+	if err != nil {
+		return "", nil, errors.Wrap(err, "failed to create temp dir")
+	}
+
+	if _, err = Apply(ctx, next, buf, WithConvertWhiteout(OverlayConvertWhiteout), WithParents(oc.lowers)); err != nil {
+		return "", nil, errors.Wrap(err, "failed to apply tar stream")
+	}
+
+	oc.lowers = append([]string{next}, oc.lowers...)
+
+	if len(oc.lowers) == 1 {
+		return oc.lowers[0], nil, nil
+	}
+
+	m := mount.Mount{
+		Type:   "overlay",
+		Source: "overlay",
+		Options: []string{
+			fmt.Sprintf("lowerdir=%s", strings.Join(oc.lowers, ":")),
+		},
+	}
+
+	if err := m.Mount(oc.merged); err != nil {
+		return "", nil, errors.Wrapf(err, "failed to mount: %v", m)
+	}
+	oc.mounted = true
+
+	return oc.merged, nil, nil
+}