package btrfs import ( "context" "io/ioutil" "os" "os/exec" "path/filepath" "strings" "testing" "github.com/containerd/containerd" "github.com/containerd/containerd/snapshot" "github.com/containerd/containerd/snapshot/testsuite" "github.com/containerd/containerd/testutil" ) const ( mib = 1024 * 1024 ) func boltSnapshotter(t *testing.T) func(context.Context, string) (snapshot.Snapshotter, func(), error) { return func(ctx context.Context, root string) (snapshot.Snapshotter, func(), error) { device := setupBtrfsLoopbackDevice(t, root) snapshotter, err := NewSnapshotter(device.deviceName, root) if err != nil { t.Fatal(err) } return snapshotter, func() { device.remove(t) }, nil } } func TestBtrfs(t *testing.T) { testutil.RequiresRoot(t) testsuite.SnapshotterSuite(t, "Btrfs", boltSnapshotter(t)) } func TestBtrfsMounts(t *testing.T) { testutil.RequiresRoot(t) ctx := context.Background() // create temporary directory for mount point mountPoint, err := ioutil.TempDir("", "containerd-btrfs-test") if err != nil { t.Fatal("could not create mount point for btrfs test", err) } defer os.RemoveAll(mountPoint) t.Log("temporary mount point created", mountPoint) root, err := ioutil.TempDir(mountPoint, "TestBtrfsPrepare-") if err != nil { t.Fatal(err) } defer os.RemoveAll(root) b, c, err := boltSnapshotter(t)(ctx, root) if err != nil { t.Fatal(err) } defer c() target := filepath.Join(root, "test") mounts, err := b.Prepare(ctx, target, "") if err != nil { t.Fatal(err) } t.Log(mounts) for _, mount := range mounts { if mount.Type != "btrfs" { t.Fatalf("wrong mount type: %v != btrfs", mount.Type) } // assumes the first, maybe incorrect in the future if !strings.HasPrefix(mount.Options[0], "subvolid=") { t.Fatalf("no subvolid option in %v", mount.Options) } } if err := os.MkdirAll(target, 0755); err != nil { t.Fatal(err) } if err := containerd.MountAll(mounts, target); err != nil { t.Fatal(err) } defer testutil.Unmount(t, target) // write in some data if err := ioutil.WriteFile(filepath.Join(target, "foo"), []byte("content"), 0777); err != nil { t.Fatal(err) } // TODO(stevvooe): We don't really make this with the driver, but that // might prove annoying in practice. if err := os.MkdirAll(filepath.Join(root, "snapshots"), 0755); err != nil { t.Fatal(err) } if err := b.Commit(ctx, filepath.Join(root, "snapshots/committed"), filepath.Join(root, "test")); err != nil { t.Fatal(err) } target = filepath.Join(root, "test2") mounts, err = b.Prepare(ctx, target, filepath.Join(root, "snapshots/committed")) if err != nil { t.Fatal(err) } if err := os.MkdirAll(target, 0755); err != nil { t.Fatal(err) } if err := containerd.MountAll(mounts, target); err != nil { t.Fatal(err) } defer testutil.Unmount(t, target) // TODO(stevvooe): Verify contents of "foo" if err := ioutil.WriteFile(filepath.Join(target, "bar"), []byte("content"), 0777); err != nil { t.Fatal(err) } if err := b.Commit(ctx, filepath.Join(root, "snapshots/committed2"), target); err != nil { t.Fatal(err) } } type testDevice struct { mountPoint string fileName string deviceName string } // setupBtrfsLoopbackDevice creates a file, mounts it as a loopback device, and // formats it as btrfs. The device should be cleaned up by calling // removeBtrfsLoopbackDevice. func setupBtrfsLoopbackDevice(t *testing.T, mountPoint string) *testDevice { // create temporary file for the disk image file, err := ioutil.TempFile("", "containerd-btrfs-test") if err != nil { t.Fatal("Could not create temporary file for btrfs test", err) } t.Log("Temporary file created", file.Name()) // initialize file with 100 MiB if err := file.Truncate(100 << 20); err != nil { t.Fatal(err) } file.Close() // create device losetup := exec.Command("losetup", "--find", "--show", file.Name()) p, err := losetup.Output() if err != nil { t.Fatal(err) } deviceName := strings.TrimSpace(string(p)) t.Log("Created loop device", deviceName) // format t.Log("Creating btrfs filesystem") mkfs := exec.Command("mkfs.btrfs", deviceName) err = mkfs.Run() if err != nil { t.Fatal("Could not run mkfs.btrfs", err) } // mount t.Logf("Mounting %s at %s", deviceName, mountPoint) mount := exec.Command("mount", deviceName, mountPoint) err = mount.Run() if err != nil { t.Fatal("Could not mount", err) } return &testDevice{ mountPoint: mountPoint, fileName: file.Name(), deviceName: deviceName, } } // remove cleans up the test device, unmounting the loopback and disk image // file. func (device *testDevice) remove(t *testing.T) { // unmount testutil.Unmount(t, device.mountPoint) // detach device t.Log("Removing loop device") losetup := exec.Command("losetup", "--detach", device.deviceName) err := losetup.Run() if err != nil { t.Error("Could not remove loop device", device.deviceName, err) } // remove file t.Log("Removing temporary file") err = os.Remove(device.fileName) if err != nil { t.Error(err) } // remove mount point t.Log("Removing temporary mount point") err = os.RemoveAll(device.mountPoint) if err != nil { t.Error(err) } }