Merge pull request #1262 from dmcgowan/more-snapshot-tests

Add snapshot test cases for former issues

.travis.yml

@@ -32,6 +32,9 @@ env:
   - TRAVIS_GOOS=linux TRAVIS_CGO_ENABLED=1
   - TRAVIS_GOOS=darwin TRAVIS_CGO_ENABLED=0
 
+before_install:
+  - uname -r
+
 install:
   - if [ "$TRAVIS_GOOS" = "windows" ] ; then sudo apt-get install -y gcc-multilib gcc-mingw-w64; export CC=x86_64-w64-mingw32-gcc ; export CXX=x86_64-w64-mingw32-g++ ; fi
   - wget https://github.com/google/protobuf/releases/download/v3.1.0/protoc-3.1.0-linux-x86_64.zip -O /tmp/protoc-3.1.0-linux-x86_64.zip

snapshot/testsuite/helpers.go

@@ -0,0 +1,120 @@
+package testsuite
+
+import (
+	"context"
+	"fmt"
+	"io/ioutil"
+	"math/rand"
+	"os"
+
+	"github.com/containerd/containerd/fs/fstest"
+	"github.com/containerd/containerd/mount"
+	"github.com/containerd/containerd/snapshot"
+	"github.com/pkg/errors"
+)
+
+func applyToMounts(m []mount.Mount, work string, a fstest.Applier) (err error) {
+	td, err := ioutil.TempDir(work, "prepare")
+	if err != nil {
+		return errors.Wrap(err, "failed to create temp dir")
+	}
+	defer os.RemoveAll(td)
+
+	if err := mount.MountAll(m, td); err != nil {
+		return err
+	}
+	defer func() {
+		if err1 := mount.UnmountAll(td, 0); err == nil {
+			err = err1
+		}
+	}()
+
+	return a.Apply(td)
+}
+
+// createSnapshot creates a new snapshot in the snapshotter
+// given an applier to run on top of the given parent.
+func createSnapshot(ctx context.Context, sn snapshot.Snapshotter, parent, work string, a fstest.Applier) (string, error) {
+	n := fmt.Sprintf("%p-%d", a, rand.Int())
+	prepare := fmt.Sprintf("%s-prepare", n)
+
+	m, err := sn.Prepare(ctx, prepare, parent)
+	if err != nil {
+		return "", err
+	}
+
+	if err := applyToMounts(m, work, a); err != nil {
+		return "", err
+	}
+
+	if err := sn.Commit(ctx, n, prepare); err != nil {
+		return "", err
+	}
+
+	return n, nil
+}
+
+func checkSnapshot(ctx context.Context, sn snapshot.Snapshotter, work, name, check string) error {
+	td, err := ioutil.TempDir(work, "check")
+	if err != nil {
+		return errors.Wrap(err, "failed to create temp dir")
+	}
+	defer os.RemoveAll(td)
+
+	view := fmt.Sprintf("%s-view", name)
+	m, err := sn.View(ctx, view, name)
+	if err != nil {
+		return errors.Wrap(err, "failed to create view")
+	}
+	defer func() {
+		if err1 := sn.Remove(ctx, view); err == nil {
+			err = errors.Wrap(err1, "failed to remove view")
+		}
+	}()
+
+	if err := mount.MountAll(m, td); err != nil {
+		return errors.Wrap(err, "failed to unmount")
+	}
+	defer func() {
+		if err1 := mount.UnmountAll(td, 0); err == nil {
+			err = errors.Wrap(err1, "failed to unmount view")
+		}
+	}()
+
+	if err := fstest.CheckDirectoryEqual(check, td); err != nil {
+		return errors.Wrap(err, "check directory failed")
+	}
+
+	return nil
+}
+
+// checkSnapshots creates a new chain of snapshots in the given snapshotter
+// using the provided appliers, checking each snapshot created in a view
+// against the changes applied to a single directory.
+func checkSnapshots(ctx context.Context, sn snapshot.Snapshotter, work string, as ...fstest.Applier) error {
+	td, err := ioutil.TempDir(work, "flat")
+	if err != nil {
+		return errors.Wrap(err, "failed to create temp dir")
+	}
+	defer os.RemoveAll(td)
+
+	var parentID string
+	for i, a := range as {
+		s, err := createSnapshot(ctx, sn, parentID, work, a)
+		if err != nil {
+			return errors.Wrapf(err, "failed to create snapshot %d", i+1)
+		}
+
+		if err := a.Apply(td); err != nil {
+			return errors.Wrapf(err, "failed to apply to check directory on %d", i+1)
+		}
+
+		if err := checkSnapshot(ctx, sn, work, s, td); err != nil {
+			return errors.Wrapf(err, "snapshot check failed on snapshot %d", i+1)
+		}
+
+		parentID = s
+	}
+	return nil
+
+}

snapshot/testsuite/issues.go

@@ -0,0 +1,172 @@
+package testsuite
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/containerd/containerd/fs/fstest"
+	"github.com/containerd/containerd/snapshot"
+)
+
+// Checks which cover former issues found in older layering models.
+//
+// NOTE: In older models, applying with tar was used to create read only layers,
+// however with the snapshot model read only layers are created just using
+// mounts and commits. Read write layers are a separate type of snapshot which
+// is not committed, avoiding any confusion in the snapshotter about whether
+// a snapshot will be mutated in the future.
+
+// checkLayerFileUpdate tests the update of a single file in an upper layer
+// Cause of issue was originally related to tar, snapshot should be able to
+// avoid such issues by not relying on tar to create layers.
+// See https://github.com/docker/docker/issues/21555
+func checkLayerFileUpdate(ctx context.Context, t *testing.T, sn snapshot.Snapshotter, work string) {
+	l1Init := fstest.Apply(
+		fstest.CreateDir("/etc", 0700),
+		fstest.CreateFile("/etc/hosts", []byte("mydomain 10.0.0.1"), 0644),
+		fstest.CreateFile("/etc/profile", []byte("PATH=/usr/bin"), 0644),
+	)
+	l2Init := fstest.Apply(
+		fstest.CreateFile("/etc/hosts", []byte("mydomain 10.0.0.2"), 0644),
+		fstest.CreateFile("/etc/profile", []byte("PATH=/usr/bin"), 0666),
+		fstest.CreateDir("/root", 0700),
+		fstest.CreateFile("/root/.bashrc", []byte("PATH=/usr/sbin:/usr/bin"), 0644),
+	)
+
+	var sleepTime time.Duration
+
+	// run 5 times to account for sporadic failure
+	for i := 0; i < 5; i++ {
+		time.Sleep(sleepTime)
+
+		if err := checkSnapshots(ctx, sn, work, l1Init, l2Init); err != nil {
+			t.Fatalf("Check snapshots failed: %+v", err)
+		}
+
+		// Sleep until next second boundary before running again
+		nextTime := time.Now()
+		sleepTime = time.Unix(nextTime.Unix()+1, 0).Sub(nextTime)
+	}
+}
+
+// checkRemoveDirectoryInLowerLayer
+// See https://github.com/docker/docker/issues/25244
+func checkRemoveDirectoryInLowerLayer(ctx context.Context, t *testing.T, sn snapshot.Snapshotter, work string) {
+	l1Init := fstest.Apply(
+		fstest.CreateDir("/lib", 0700),
+		fstest.CreateFile("/lib/hidden", []byte{}, 0644),
+	)
+	l2Init := fstest.Apply(
+		fstest.RemoveAll("/lib"),
+		fstest.CreateDir("/lib", 0700),
+		fstest.CreateFile("/lib/not-hidden", []byte{}, 0644),
+	)
+	l3Init := fstest.Apply(
+		fstest.CreateFile("/lib/newfile", []byte{}, 0644),
+	)
+
+	if err := checkSnapshots(ctx, sn, work, l1Init, l2Init, l3Init); err != nil {
+		t.Fatalf("Check snapshots failed: %+v", err)
+	}
+}
+
+// checkChown
+// See https://github.com/docker/docker/issues/20240 aufs
+// See https://github.com/docker/docker/issues/24913 overlay
+// see https://github.com/docker/docker/issues/28391 overlay2
+func checkChown(ctx context.Context, t *testing.T, sn snapshot.Snapshotter, work string) {
+	l1Init := fstest.Apply(
+		fstest.CreateDir("/opt", 0700),
+		fstest.CreateDir("/opt/a", 0700),
+		fstest.CreateDir("/opt/a/b", 0700),
+		fstest.CreateFile("/opt/a/b/file.txt", []byte("hello"), 0644),
+	)
+	l2Init := fstest.Apply(
+		fstest.Chown("/opt", 1, 1),
+		fstest.Chown("/opt/a", 1, 1),
+		fstest.Chown("/opt/a/b", 1, 1),
+		fstest.Chown("/opt/a/b/file.txt", 1, 1),
+	)
+
+	if err := checkSnapshots(ctx, sn, work, l1Init, l2Init); err != nil {
+		t.Fatalf("Check snapshots failed: %+v", err)
+	}
+}
+
+// checkRename
+// https://github.com/docker/docker/issues/25409
+func checkRename(ctx context.Context, t *testing.T, sn snapshot.Snapshotter, work string) {
+	l1Init := fstest.Apply(
+		fstest.CreateDir("/dir1", 0700),
+		fstest.CreateDir("/somefiles", 0700),
+		fstest.CreateFile("/somefiles/f1", []byte("was here first!"), 0644),
+		fstest.CreateFile("/somefiles/f2", []byte("nothing interesting"), 0644),
+	)
+	l2Init := fstest.Apply(
+		fstest.Rename("/dir1", "/dir2"),
+		fstest.CreateFile("/somefiles/f1-overwrite", []byte("new content 1"), 0644),
+		fstest.Rename("/somefiles/f1-overwrite", "/somefiles/f1"),
+		fstest.Rename("/somefiles/f2", "/somefiles/f3"),
+	)
+
+	if err := checkSnapshots(ctx, sn, work, l1Init, l2Init); err != nil {
+		t.Fatalf("Check snapshots failed: %+v", err)
+	}
+}
+
+// checkDirectoryPermissionOnCommit
+// https://github.com/docker/docker/issues/27298
+func checkDirectoryPermissionOnCommit(ctx context.Context, t *testing.T, sn snapshot.Snapshotter, work string) {
+	l1Init := fstest.Apply(
+		fstest.CreateDir("/dir1", 0700),
+		fstest.CreateDir("/dir2", 0700),
+		fstest.CreateDir("/dir3", 0700),
+		fstest.CreateDir("/dir4", 0700),
+		fstest.CreateFile("/dir4/f1", []byte("..."), 0644),
+		fstest.CreateDir("/dir5", 0700),
+		fstest.CreateFile("/dir5/f1", []byte("..."), 0644),
+		fstest.Chown("/dir1", 1, 1),
+		fstest.Chown("/dir2", 1, 1),
+		fstest.Chown("/dir3", 1, 1),
+		fstest.Chown("/dir5", 1, 1),
+		fstest.Chown("/dir5/f1", 1, 1),
+	)
+	l2Init := fstest.Apply(
+		fstest.Chown("/dir2", 0, 0),
+		fstest.RemoveAll("/dir3"),
+		fstest.Chown("/dir4", 1, 1),
+		fstest.Chown("/dir4/f1", 1, 1),
+	)
+	l3Init := fstest.Apply(
+		fstest.CreateDir("/dir3", 0700),
+		fstest.Chown("/dir3", 1, 1),
+		fstest.RemoveAll("/dir5"),
+		fstest.CreateDir("/dir5", 0700),
+		fstest.Chown("/dir5", 1, 1),
+	)
+
+	if err := checkSnapshots(ctx, sn, work, l1Init, l2Init, l3Init); err != nil {
+		t.Fatalf("Check snapshots failed: %+v", err)
+	}
+}
+
+// More issues to test
+//
+// checkRemoveAfterCommit
+// See https://github.com/docker/docker/issues/24309
+//
+// checkUnixDomainSockets
+// See https://github.com/docker/docker/issues/12080
+//
+// checkDirectoryInodeStability
+// See https://github.com/docker/docker/issues/19647
+//
+// checkOpenFileInodeStability
+// See https://github.com/docker/docker/issues/12327
+//
+// checkGetCWD
+// See https://github.com/docker/docker/issues/19082
+//
+// checkChmod
+// See https://github.com/docker/machine/issues/3327

snapshot/testsuite/testsuite.go

@@ -23,6 +23,14 @@ func SnapshotterSuite(t *testing.T, name string, snapshotterFn func(ctx context.
 	t.Run("StatComitted", makeTest(t, name, snapshotterFn, checkSnapshotterStatCommitted))
 	t.Run("TransitivityTest", makeTest(t, name, snapshotterFn, checkSnapshotterTransitivity))
 	t.Run("PreareViewFailingtest", makeTest(t, name, snapshotterFn, checkSnapshotterPrepareView))
+
+	t.Run("LayerFileupdate", makeTest(t, name, snapshotterFn, checkLayerFileUpdate))
+	t.Run("RemoveDirectoryInLowerLayer", makeTest(t, name, snapshotterFn, checkRemoveDirectoryInLowerLayer))
+	t.Run("Chown", makeTest(t, name, snapshotterFn, checkChown))
+	t.Run("DirectoryPermissionOnCommit", makeTest(t, name, snapshotterFn, checkDirectoryPermissionOnCommit))
+
+	// Rename test still fails on some kernels with overlay
+	//t.Run("Rename", makeTest(t, name, snapshotterFn, checkRename))
 }
 
 func makeTest(t *testing.T, name string, snapshotterFn func(ctx context.Context, root string) (snapshot.Snapshotter, func(), error), fn func(ctx context.Context, t *testing.T, snapshotter snapshot.Snapshotter, work string)) func(t *testing.T) {