buildkit/snapshot/snapshotter_test.go

630 lines
18 KiB
Go

//go:build linux
// +build linux
package snapshot
import (
"context"
"fmt"
"io/ioutil"
"os"
"path/filepath"
"strings"
"syscall"
"testing"
"time"
"github.com/containerd/containerd/content/local"
"github.com/containerd/containerd/leases"
ctdmetadata "github.com/containerd/containerd/metadata"
"github.com/containerd/containerd/mount"
"github.com/containerd/containerd/namespaces"
"github.com/containerd/containerd/snapshots"
"github.com/containerd/containerd/snapshots/native"
"github.com/containerd/containerd/snapshots/overlay"
"github.com/containerd/continuity/fs/fstest"
"github.com/hashicorp/go-multierror"
"github.com/moby/buildkit/identity"
"github.com/moby/buildkit/util/leaseutil"
"github.com/stretchr/testify/require"
bolt "go.etcd.io/bbolt"
)
func newSnapshotter(ctx context.Context, snapshotterName string) (_ context.Context, _ *mergeSnapshotter, _ func() error, rerr error) {
ns := "buildkit-test"
ctx = namespaces.WithNamespace(ctx, ns)
defers := make([]func() error, 0)
cleanup := func() error {
var err error
for i := range defers {
err = multierror.Append(err, defers[len(defers)-1-i]()).ErrorOrNil()
}
return err
}
defer func() {
if rerr != nil && cleanup != nil {
cleanup()
}
}()
tmpdir, err := ioutil.TempDir("", "buildkit-test")
if err != nil {
return nil, nil, nil, err
}
defers = append(defers, func() error {
return os.RemoveAll(tmpdir)
})
var ctdSnapshotter snapshots.Snapshotter
var noHardlink bool
switch snapshotterName {
case "native-nohardlink":
noHardlink = true
fallthrough
case "native":
ctdSnapshotter, err = native.NewSnapshotter(filepath.Join(tmpdir, "snapshots"))
if err != nil {
return nil, nil, nil, err
}
case "overlayfs":
ctdSnapshotter, err = overlay.NewSnapshotter(filepath.Join(tmpdir, "snapshots"))
if err != nil {
return nil, nil, nil, err
}
default:
return nil, nil, nil, fmt.Errorf("unhandled snapshotter: %s", snapshotterName)
}
store, err := local.NewStore(tmpdir)
if err != nil {
return nil, nil, nil, err
}
db, err := bolt.Open(filepath.Join(tmpdir, "containerdmeta.db"), 0644, nil)
if err != nil {
return nil, nil, nil, err
}
defers = append(defers, func() error {
return db.Close()
})
mdb := ctdmetadata.NewDB(db, store, map[string]snapshots.Snapshotter{
snapshotterName: ctdSnapshotter,
})
if err := mdb.Init(context.TODO()); err != nil {
return nil, nil, nil, err
}
lm := leaseutil.WithNamespace(ctdmetadata.NewLeaseManager(mdb), ns)
snapshotter := NewMergeSnapshotter(ctx, FromContainerdSnapshotter(snapshotterName, mdb.Snapshotter(snapshotterName), nil), lm).(*mergeSnapshotter)
if noHardlink {
snapshotter.useHardlinks = false
}
leaseID := identity.NewID()
_, err = lm.Create(ctx, func(l *leases.Lease) error {
l.ID = leaseID
l.Labels = map[string]string{
"containerd.io/gc.flat": time.Now().UTC().Format(time.RFC3339Nano),
}
return nil
}, leaseutil.MakeTemporary)
if err != nil {
return nil, nil, nil, err
}
ctx = leases.WithLease(ctx, leaseID)
return ctx, snapshotter, cleanup, nil
}
func TestMerge(t *testing.T) {
for _, snName := range []string{"overlayfs", "native", "native-nohardlink"} {
snName := snName
t.Run(snName, func(t *testing.T) {
t.Parallel()
if snName == "overlayfs" {
requireRoot(t)
}
ctx, sn, cleanup, err := newSnapshotter(context.Background(), snName)
require.NoError(t, err)
defer cleanup()
ts := time.Unix(0, 0)
snapA := committedKey(ctx, t, sn, identity.NewID(), "",
fstest.CreateFile("foo", []byte("A"), 0777),
fstest.Lchtimes("foo", ts, ts.Add(2*time.Second)),
fstest.CreateFile("a", []byte("A"), 0777),
fstest.Lchtimes("a", ts, ts.Add(4*time.Second)),
fstest.CreateDir("bar", 0700),
fstest.CreateFile("bar/A", []byte("A"), 0777),
fstest.Lchtimes("bar/A", ts, ts.Add(6*time.Second)),
fstest.Lchtimes("bar", ts, ts.Add(6*time.Second)),
)
snapB := committedKey(ctx, t, sn, identity.NewID(), snapA.Name,
fstest.Remove("/foo"),
fstest.CreateFile("b", []byte("B"), 0777),
fstest.Lchtimes("b", ts, ts.Add(4*time.Second)),
fstest.CreateFile("bar/B", []byte("B"), 0774),
fstest.Lchtimes("bar/B", ts, ts.Add(9*time.Second)),
fstest.Lchtimes("bar", ts, ts.Add(9*time.Second)),
)
snapC := committedKey(ctx, t, sn, identity.NewID(), "",
fstest.CreateFile("foo", []byte("C"), 0775),
fstest.Lchtimes("foo", ts, ts.Add(4*time.Second)),
fstest.CreateFile("c", []byte("C"), 0777),
fstest.Lchtimes("c", ts, ts.Add(6*time.Second)),
fstest.CreateDir("bar", 0777),
fstest.CreateFile("bar/A", []byte("C"), 0400),
fstest.Lchtimes("bar/A", ts, ts.Add(12*time.Second)),
fstest.Lchtimes("bar", ts, ts.Add(12*time.Second)),
fstest.Symlink("foo", "symlink"),
fstest.Lchtimes("symlink", ts, ts.Add(3*time.Second)),
fstest.Link("bar/A", "hardlink"),
fstest.Symlink("../..", "dontfollowme"),
fstest.Lchtimes("dontfollowme", ts, ts.Add(2*time.Second)),
)
mergeA := mergeKey(ctx, t, sn, identity.NewID(), []Diff{
{"", snapA.Name}, {snapA.Name, snapB.Name},
{"", snapC.Name},
})
requireContents(ctx, t, sn, mergeA.Name,
fstest.CreateFile("a", []byte("A"), 0777),
fstest.CreateFile("b", []byte("B"), 0777),
fstest.CreateFile("c", []byte("C"), 0777),
fstest.CreateFile("foo", []byte("C"), 0775),
fstest.CreateDir("bar", 0777),
fstest.CreateFile("bar/A", []byte("C"), 0400),
fstest.CreateFile("bar/B", []byte("B"), 0774),
fstest.Symlink("foo", "symlink"),
fstest.Link("bar/A", "hardlink"),
fstest.Symlink("../..", "dontfollowme"),
)
withMount(ctx, t, sn, mergeA.Name, func(root string) {
requireMtime(t, filepath.Join(root, "a"), ts.Add(4*time.Second))
requireMtime(t, filepath.Join(root, "b"), ts.Add(4*time.Second))
requireMtime(t, filepath.Join(root, "c"), ts.Add(6*time.Second))
requireMtime(t, filepath.Join(root, "foo"), ts.Add(4*time.Second))
requireMtime(t, filepath.Join(root, "bar"), ts.Add(12*time.Second))
requireMtime(t, filepath.Join(root, "bar/A"), ts.Add(12*time.Second))
requireMtime(t, filepath.Join(root, "bar/B"), ts.Add(9*time.Second))
requireMtime(t, filepath.Join(root, "symlink"), ts.Add(3*time.Second))
requireMtime(t, filepath.Join(root, "dontfollowme"), ts.Add(2*time.Second))
})
mergeB := mergeKey(ctx, t, sn, identity.NewID(), []Diff{
{"", snapC.Name},
{"", snapA.Name}, {snapA.Name, snapB.Name},
})
requireContents(ctx, t, sn, mergeB.Name,
fstest.CreateFile("a", []byte("A"), 0777),
fstest.CreateFile("b", []byte("B"), 0777),
fstest.CreateFile("c", []byte("C"), 0777),
fstest.CreateDir("bar", 0700),
fstest.CreateFile("bar/A", []byte("A"), 0777),
fstest.CreateFile("bar/B", []byte("B"), 0774),
fstest.Symlink("foo", "symlink"),
fstest.CreateFile("hardlink", []byte("C"), 0400), // bar/A was overwritten, not considered hardlink
fstest.Symlink("../..", "dontfollowme"),
)
withMount(ctx, t, sn, mergeB.Name, func(root string) {
requireMtime(t, filepath.Join(root, "a"), ts.Add(4*time.Second))
requireMtime(t, filepath.Join(root, "b"), ts.Add(4*time.Second))
requireMtime(t, filepath.Join(root, "c"), ts.Add(6*time.Second))
requireMtime(t, filepath.Join(root, "bar"), ts.Add(9*time.Second))
requireMtime(t, filepath.Join(root, "bar/A"), ts.Add(6*time.Second))
requireMtime(t, filepath.Join(root, "bar/B"), ts.Add(9*time.Second))
requireMtime(t, filepath.Join(root, "symlink"), ts.Add(3*time.Second))
requireMtime(t, filepath.Join(root, "dontfollowme"), ts.Add(2*time.Second))
})
snapD := committedKey(ctx, t, sn, identity.NewID(), "",
fstest.CreateDir("bar", 0750),
fstest.CreateFile("bar/D", []byte("D"), 0444),
fstest.CreateDir("fs", 0770),
fstest.CreateFile("x", []byte("X"), 0400),
fstest.Link("x", "hardlink"),
fstest.Symlink("fs", "symlink"),
fstest.Link("symlink", "hardsymlink"),
)
mergeC := mergeKey(ctx, t, sn, identity.NewID(), []Diff{
// mergeA
{"", snapA.Name}, {snapA.Name, snapB.Name},
{"", snapC.Name},
// mergeB
{"", snapC.Name},
{"", snapA.Name}, {snapA.Name, snapB.Name},
// snapD
{"", snapD.Name},
})
requireContents(ctx, t, sn, mergeC.Name,
fstest.CreateFile("a", []byte("A"), 0777),
fstest.CreateFile("b", []byte("B"), 0777),
fstest.CreateFile("c", []byte("C"), 0777),
fstest.CreateDir("bar", 0750),
fstest.CreateFile("bar/A", []byte("A"), 0777),
fstest.CreateFile("bar/B", []byte("B"), 0774),
fstest.CreateFile("bar/D", []byte("D"), 0444),
fstest.CreateDir("fs", 0770),
fstest.CreateFile("x", []byte("X"), 0400),
fstest.Link("x", "hardlink"),
fstest.Symlink("fs", "symlink"),
fstest.Link("symlink", "hardsymlink"),
fstest.Symlink("../..", "dontfollowme"),
)
snapE := committedKey(ctx, t, sn, identity.NewID(), "",
fstest.CreateFile("qaz", nil, 0444),
fstest.CreateDir("bar", 0777),
fstest.CreateFile("bar/B", []byte("B"), 0444),
)
snapF := committedKey(ctx, t, sn, identity.NewID(), mergeC.Name,
fstest.Remove("a"),
fstest.CreateDir("a", 0770),
fstest.Rename("b", "a/b"),
fstest.Rename("c", "a/c"),
fstest.RemoveAll("bar"),
fstest.CreateDir("bar", 0777),
fstest.CreateFile("bar/D", []byte("D2"), 0444),
fstest.RemoveAll("fs"),
fstest.CreateFile("fs", nil, 0764),
fstest.Remove("x"),
fstest.CreateDir("x", 0555),
fstest.Remove("hardsymlink"),
fstest.CreateDir("hardsymlink", 0707),
)
mergeD := mergeKey(ctx, t, sn, identity.NewID(), []Diff{
{"", snapE.Name},
// mergeC
{"", snapA.Name}, {snapA.Name, snapB.Name},
{"", snapC.Name},
{"", snapC.Name},
{"", snapA.Name}, {snapA.Name, snapB.Name},
{"", snapD.Name},
// snapF
{mergeC.Name, snapF.Name},
})
requireContents(ctx, t, sn, mergeD.Name,
fstest.CreateDir("a", 0770),
fstest.CreateFile("a/b", []byte("B"), 0777),
fstest.CreateDir("bar", 0777),
fstest.CreateFile("a/c", []byte("C"), 0777),
fstest.CreateFile("bar/D", []byte("D2"), 0444),
fstest.CreateFile("fs", nil, 0764),
fstest.CreateDir("x", 0555),
fstest.CreateFile("hardlink", []byte("X"), 0400),
fstest.Symlink("fs", "symlink"),
fstest.CreateDir("hardsymlink", 0707),
fstest.Symlink("../..", "dontfollowme"),
fstest.CreateFile("qaz", nil, 0444),
)
})
}
}
func TestHardlinks(t *testing.T) {
for _, snName := range []string{"overlayfs", "native"} {
snName := snName
t.Run(snName, func(t *testing.T) {
t.Parallel()
if snName == "overlayfs" {
requireRoot(t)
}
ctx, sn, cleanup, err := newSnapshotter(context.Background(), snName)
require.NoError(t, err)
defer cleanup()
base1Snap := committedKey(ctx, t, sn, identity.NewID(), "",
fstest.CreateFile("1", []byte("1"), 0600),
)
base2Snap := committedKey(ctx, t, sn, identity.NewID(), "",
fstest.CreateFile("2", []byte("2"), 0600),
)
mergeSnap := mergeKey(ctx, t, sn, identity.NewID(), []Diff{
{"", base1Snap.Name},
{"", base2Snap.Name},
})
stat1 := statPath(ctx, t, sn, mergeSnap.Name, "1")
var expected1Links int
switch snName {
case "overlayfs":
// base merge input is used as parent, not merged with hardlinks
expected1Links = 1
case "native":
expected1Links = 2
}
require.EqualValues(t, expected1Links, stat1.Nlink)
stat1Ino := stat1.Ino
stat2 := statPath(ctx, t, sn, mergeSnap.Name, "2")
require.EqualValues(t, 2, stat2.Nlink)
stat2Ino := stat2.Ino
childSnap := committedKey(ctx, t, sn, identity.NewID(), mergeSnap.Name,
fstest.CreateFile("1", []byte("11"), 0644),
fstest.CreateFile("2", []byte("22"), 0644),
)
stat1 = statPath(ctx, t, sn, childSnap.Name, "1")
require.EqualValues(t, 1, stat1.Nlink)
require.NotEqualValues(t, stat1Ino, stat1.Ino)
stat2 = statPath(ctx, t, sn, childSnap.Name, "2")
require.EqualValues(t, 1, stat2.Nlink)
require.NotEqualValues(t, stat2Ino, stat2.Ino)
// verify the original files and the files inthe merge are unchanged
requireContents(ctx, t, sn, base1Snap.Name,
fstest.CreateFile("1", []byte("1"), 0600),
)
requireContents(ctx, t, sn, base2Snap.Name,
fstest.CreateFile("2", []byte("2"), 0600),
)
requireContents(ctx, t, sn, mergeSnap.Name,
fstest.CreateFile("1", []byte("1"), 0600),
fstest.CreateFile("2", []byte("2"), 0600),
)
})
}
}
func TestUsage(t *testing.T) {
for _, snName := range []string{"overlayfs", "native", "native-nohardlink"} {
snName := snName
t.Run(snName, func(t *testing.T) {
t.Parallel()
if snName == "overlayfs" {
requireRoot(t)
}
ctx, sn, cleanup, err := newSnapshotter(context.Background(), snName)
require.NoError(t, err)
defer cleanup()
const direntByteSize = 4096
base1Snap := committedKey(ctx, t, sn, identity.NewID(), "",
fstest.CreateDir("foo", 0777),
fstest.CreateFile("foo/1", []byte("a"), 0777),
)
require.EqualValues(t, 3, base1Snap.Inodes)
require.EqualValues(t, 3*direntByteSize, base1Snap.Size)
base2Snap := committedKey(ctx, t, sn, identity.NewID(), "",
fstest.CreateDir("foo", 0777),
fstest.CreateFile("foo/2", []byte("aa"), 0777),
)
require.EqualValues(t, 3, base2Snap.Inodes)
require.EqualValues(t, 3*direntByteSize, base2Snap.Size)
base3Snap := committedKey(ctx, t, sn, identity.NewID(), "",
fstest.CreateDir("foo", 0777),
fstest.CreateFile("foo/3", []byte("aaa"), 0777),
fstest.CreateFile("bar", nil, 0777),
)
require.EqualValues(t, 4, base3Snap.Inodes)
require.EqualValues(t, 3*direntByteSize, base3Snap.Size)
mergeSnap := mergeKey(ctx, t, sn, identity.NewID(), []Diff{
{"", base1Snap.Name},
{"", base2Snap.Name},
{"", base3Snap.Name},
})
switch snName {
case "overlayfs", "native":
// / and /foo were created/copied. Others should be hard-linked
require.EqualValues(t, 2, mergeSnap.Inodes)
require.EqualValues(t, 2*direntByteSize, mergeSnap.Size)
case "native-nohardlink":
require.EqualValues(t, 6, mergeSnap.Inodes)
require.EqualValues(t, 5*direntByteSize, mergeSnap.Size)
}
})
}
}
type snapshotInfo struct {
snapshots.Info
snapshots.Usage
}
func getInfo(ctx context.Context, t *testing.T, sn *mergeSnapshotter, key string) snapshotInfo {
t.Helper()
info, err := sn.Stat(ctx, key)
require.NoError(t, err)
usage, err := sn.Usage(ctx, key)
require.NoError(t, err)
return snapshotInfo{info, usage}
}
func activeKey(
ctx context.Context,
t *testing.T,
sn *mergeSnapshotter,
key string,
parent string,
files ...fstest.Applier,
) snapshotInfo {
t.Helper()
err := sn.Prepare(ctx, key, parent)
require.NoError(t, err)
if len(files) > 0 {
mnts, cleanup := getMounts(ctx, t, sn, key)
defer cleanup()
mnter := LocalMounterWithMounts(mnts)
root, err := mnter.Mount()
require.NoError(t, err)
defer mnter.Unmount()
require.NoError(t, fstest.Apply(files...).Apply(root))
}
return getInfo(ctx, t, sn, key)
}
func commitActiveKey(
ctx context.Context,
t *testing.T,
sn *mergeSnapshotter,
name string,
activeKey string,
) snapshotInfo {
t.Helper()
err := sn.Commit(ctx, name, activeKey)
require.NoError(t, err)
return getInfo(ctx, t, sn, name)
}
func committedKey(
ctx context.Context,
t *testing.T,
sn *mergeSnapshotter,
key string,
parent string,
files ...fstest.Applier,
) snapshotInfo {
t.Helper()
prepareKey := identity.NewID()
activeKey(ctx, t, sn, prepareKey, parent, files...)
return commitActiveKey(ctx, t, sn, key, prepareKey)
}
func mergeKey(
ctx context.Context,
t *testing.T,
sn *mergeSnapshotter,
key string,
diffs []Diff,
) snapshotInfo {
t.Helper()
err := sn.Merge(ctx, key, diffs)
require.NoError(t, err)
return getInfo(ctx, t, sn, key)
}
func getMounts(ctx context.Context, t *testing.T, sn *mergeSnapshotter, key string) ([]mount.Mount, func() error) {
t.Helper()
var mntable Mountable
var err error
if info := getInfo(ctx, t, sn, key); info.Kind == snapshots.KindCommitted {
mntable, err = sn.View(ctx, identity.NewID(), key)
} else {
mntable, err = sn.Mounts(ctx, key)
}
require.NoError(t, err)
mnts, cleanup, err := mntable.Mount()
require.NoError(t, err)
return mnts, cleanup
}
func withMount(ctx context.Context, t *testing.T, sn *mergeSnapshotter, key string, f func(root string)) {
t.Helper()
mounts, cleanup := getMounts(ctx, t, sn, key)
defer cleanup()
mnter := LocalMounterWithMounts(mounts)
root, err := mnter.Mount()
require.NoError(t, err)
defer mnter.Unmount()
f(root)
}
func requireContents(ctx context.Context, t *testing.T, sn *mergeSnapshotter, key string, files ...fstest.Applier) {
t.Helper()
withMount(ctx, t, sn, key, func(root string) {
require.NoError(t, fstest.CheckDirectoryEqualWithApplier(root, fstest.Apply(files...)))
})
}
func trySyscallStat(t *testing.T, path string) *syscall.Stat_t {
t.Helper()
info, err := os.Stat(path)
if err == nil {
return info.Sys().(*syscall.Stat_t)
}
require.ErrorIs(t, err, os.ErrNotExist)
return nil
}
func requireMtime(t *testing.T, path string, mtime time.Time) {
t.Helper()
info, err := os.Lstat(path)
require.NoError(t, err)
stat := info.Sys().(*syscall.Stat_t)
require.Equal(t, mtime.UnixNano(), stat.Mtim.Nano())
}
func tryStatPath(ctx context.Context, t *testing.T, sn *mergeSnapshotter, key, path string) (st *syscall.Stat_t) {
t.Helper()
mounts, cleanup := getMounts(ctx, t, sn, key)
defer cleanup()
require.Len(t, mounts, 1)
mnt := mounts[0]
if mnt.Type == "overlay" {
var upperdir string
var lowerdirs []string
for _, opt := range mnt.Options {
if strings.HasPrefix(opt, "upperdir=") {
upperdir = strings.SplitN(opt, "upperdir=", 2)[1]
} else if strings.HasPrefix(opt, "lowerdir=") {
lowerdirs = strings.Split(strings.SplitN(opt, "lowerdir=", 2)[1], ":")
}
}
if upperdir != "" {
st = trySyscallStat(t, filepath.Join(upperdir, path))
if st != nil {
return st
}
}
for _, lowerdir := range lowerdirs {
st = trySyscallStat(t, filepath.Join(lowerdir, path))
if st != nil {
return st
}
}
return nil
}
withMount(ctx, t, sn, key, func(root string) {
st = trySyscallStat(t, filepath.Join(root, path))
})
return st
}
func statPath(ctx context.Context, t *testing.T, sn *mergeSnapshotter, key, path string) (st *syscall.Stat_t) {
t.Helper()
st = tryStatPath(ctx, t, sn, key, path)
require.NotNil(t, st)
return st
}
func requireRoot(t *testing.T) {
t.Helper()
if os.Getuid() != 0 {
t.Skip("test requires root")
}
}