fuse-overlayfs: enable shifting

Makefile

@@ -86,6 +86,7 @@ install.tools:
 	go get -u $(BUILDFLAGS) github.com/cpuguy83/go-md2man
 	go get -u $(BUILDFLAGS) github.com/vbatts/git-validation
 	go get -u $(BUILDFLAGS) gopkg.in/alecthomas/gometalinter.v1
+	go get -u $(BUILDFLAGS) github.com/pquerna/ffjson
 	gometalinter.v1 -i
 
 help: ## this help

drivers/aufs/aufs.go

@@ -416,7 +416,7 @@ func atomicRemove(source string) error {
 
 // Get returns the rootfs path for the id.
 // This will mount the dir at its given path
-func (a *Driver) Get(id, mountLabel string) (string, error) {
+func (a *Driver) Get(id, mountLabel string, uidMaps, gidMaps []idtools.IDMap) (string, error) {
 	a.locker.Lock(id)
 	defer a.locker.Unlock(id)
 	parents, err := a.getParentLayerPaths(id)
@@ -728,3 +728,8 @@ func useDirperm() bool {
 func (a *Driver) UpdateLayerIDMap(id string, toContainer, toHost *idtools.IDMappings, mountLabel string) error {
 	return fmt.Errorf("aufs doesn't support changing ID mappings")
 }
+
+// SupportsShifting tells whether the driver support shifting of the UIDs/GIDs in an userNS
+func (a *Driver) SupportsShifting() bool {
+	return false
+}

drivers/aufs/aufs_test.go

@@ -44,7 +44,7 @@ func testInit(dir string, t testing.TB) graphdriver.Driver {
 }
 
 func driverGet(d *Driver, id string, mntLabel string) (string, error) {
-	return d.Get(id, mntLabel)
+	return d.Get(id, mntLabel, nil, nil)
 }
 
 func newDriver(t testing.TB) *Driver {
@@ -171,7 +171,7 @@ func TestGetWithoutParent(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	diffPath, err := d.Get("1", "")
+	diffPath, err := d.Get("1", "", nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -224,7 +224,7 @@ func TestMountedTrueResponse(t *testing.T) {
 	err = d.Create("2", "1", nil)
 	require.NoError(t, err)
 
-	_, err = d.Get("2", "")
+	_, err = d.Get("2", "", nil, nil)
 	require.NoError(t, err)
 
 	response, err := d.mounted(d.pathCache["2"])
@@ -249,7 +249,7 @@ func TestMountWithParent(t *testing.T) {
 		}
 	}()
 
-	mntPath, err := d.Get("2", "")
+	mntPath, err := d.Get("2", "", nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -280,7 +280,7 @@ func TestRemoveMountedDir(t *testing.T) {
 		}
 	}()
 
-	mntPath, err := d.Get("2", "")
+	mntPath, err := d.Get("2", "", nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -760,7 +760,7 @@ func BenchmarkConcurrentAccess(b *testing.B) {
 			for i := 0; i < b.N; i++ {
 				innerGroup.Add(1)
 				go func() {
-					d.Get(id, "")
+					d.Get(id, "", nil, nil)
 					d.Put(id)
 					innerGroup.Done()
 				}()

drivers/btrfs/btrfs.go

@@ -634,7 +634,7 @@ func (d *Driver) Remove(id string) error {
 }
 
 // Get the requested filesystem id.
-func (d *Driver) Get(id, mountLabel string) (string, error) {
+func (d *Driver) Get(id, mountLabel string, uidMaps, gidMaps []idtools.IDMap) (string, error) {
 	dir := d.subvolumesDirID(id)
 	st, err := os.Stat(dir)
 	if err != nil {

drivers/btrfs/btrfs_test.go

@@ -35,7 +35,7 @@ func TestBtrfsSubvolDelete(t *testing.T) {
 	}
 	defer graphtest.PutDriver(t)
 
-	dir, err := d.Get("test", "")
+	dir, err := d.Get("test", "", nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}

drivers/chown.go

@@ -114,7 +114,7 @@ func NewNaiveLayerIDMapUpdater(driver ProtoDriver) LayerIDMapUpdater {
 // same "container" IDs.
 func (n *naiveLayerIDMapUpdater) UpdateLayerIDMap(id string, toContainer, toHost *idtools.IDMappings, mountLabel string) error {
 	driver := n.ProtoDriver
-	layerFs, err := driver.Get(id, mountLabel)
+	layerFs, err := driver.Get(id, mountLabel, nil, nil)
 	if err != nil {
 		return err
 	}
@@ -124,3 +124,8 @@ func (n *naiveLayerIDMapUpdater) UpdateLayerIDMap(id string, toContainer, toHost
 
 	return ChownPathByMaps(layerFs, toContainer, toHost)
 }
+
+// SupportsShifting tells whether the driver support shifting of the UIDs/GIDs in an userNS
+func (n *naiveLayerIDMapUpdater) SupportsShifting() bool {
+	return false
+}

drivers/devmapper/driver.go

@@ -163,7 +163,7 @@ func (d *Driver) Remove(id string) error {
 }
 
 // Get mounts a device with given id into the root filesystem
-func (d *Driver) Get(id, mountLabel string) (string, error) {
+func (d *Driver) Get(id, mountLabel string, uidMaps, gidMaps []idtools.IDMap) (string, error) {
 	d.locker.Lock(id)
 	defer d.locker.Unlock(id)
 	mp := path.Join(d.home, "mnt", id)

drivers/driver.go

@@ -66,8 +66,9 @@ type ProtoDriver interface {
 	Remove(id string) error
 	// Get returns the mountpoint for the layered filesystem referred
 	// to by this id. You can optionally specify a mountLabel or "".
+	// Optionally it gets the mappings used to create the layer.
 	// Returns the absolute path to the mounted layered filesystem.
-	Get(id, mountLabel string) (dir string, err error)
+	Get(id, mountLabel string, uidMaps, gidMaps []idtools.IDMap) (dir string, err error)
 	// Put releases the system resources for the specified id,
 	// e.g, unmounting layered filesystem.
 	Put(id string) error
@@ -118,6 +119,10 @@ type LayerIDMapUpdater interface {
 	// relative to a parent layer, but before this method is called, may be discarded
 	// by Diff().
 	UpdateLayerIDMap(id string, toContainer, toHost *idtools.IDMappings, mountLabel string) error
+
+	// SupportsShifting tells whether the driver support shifting of the UIDs/GIDs in a
+	// image and it is not required to Chown the files when running in an user namespace.
+	SupportsShifting() bool
 }
 
 // Driver is the interface for layered/snapshot file system drivers.

drivers/fsdiff.go

@@ -51,7 +51,7 @@ func (gdw *NaiveDiffDriver) Diff(id string, idMappings *idtools.IDMappings, pare
 		parentMappings = &idtools.IDMappings{}
 	}
 
-	layerFs, err := driver.Get(id, mountLabel)
+	layerFs, err := driver.Get(id, mountLabel, nil, nil)
 	if err != nil {
 		return nil, err
 	}
@@ -78,7 +78,7 @@ func (gdw *NaiveDiffDriver) Diff(id string, idMappings *idtools.IDMappings, pare
 		}), nil
 	}
 
-	parentFs, err := driver.Get(parent, mountLabel)
+	parentFs, err := driver.Get(parent, mountLabel, nil, nil)
 	if err != nil {
 		return nil, err
 	}
@@ -119,7 +119,7 @@ func (gdw *NaiveDiffDriver) Changes(id string, idMappings *idtools.IDMappings, p
 		parentMappings = &idtools.IDMappings{}
 	}
 
-	layerFs, err := driver.Get(id, mountLabel)
+	layerFs, err := driver.Get(id, mountLabel, nil, nil)
 	if err != nil {
 		return nil, err
 	}
@@ -128,7 +128,7 @@ func (gdw *NaiveDiffDriver) Changes(id string, idMappings *idtools.IDMappings, p
 	parentFs := ""
 
 	if parent != "" {
-		parentFs, err = driver.Get(parent, mountLabel)
+		parentFs, err = driver.Get(parent, mountLabel, nil, nil)
 		if err != nil {
 			return nil, err
 		}
@@ -149,7 +149,7 @@ func (gdw *NaiveDiffDriver) ApplyDiff(id string, applyMappings *idtools.IDMappin
 	}
 
 	// Mount the root filesystem so we can apply the diff/layer.
-	layerFs, err := driver.Get(id, mountLabel)
+	layerFs, err := driver.Get(id, mountLabel, nil, nil)
 	if err != nil {
 		return
 	}
@@ -189,7 +189,7 @@ func (gdw *NaiveDiffDriver) DiffSize(id string, idMappings *idtools.IDMappings,
 		return
 	}
 
-	layerFs, err := driver.Get(id, mountLabel)
+	layerFs, err := driver.Get(id, mountLabel, nil, nil)
 	if err != nil {
 		return
 	}

drivers/graphtest/graphbench_unix.go

@@ -44,7 +44,7 @@ func DriverBenchGetEmpty(b *testing.B, drivername string, driveroptions ...strin
 
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		_, err := driver.Get(base, "")
+		_, err := driver.Get(base, "", nil, nil)
 		b.StopTimer()
 		if err != nil {
 			b.Fatalf("Error getting mount: %s", err)
@@ -235,7 +235,7 @@ func DriverBenchDeepLayerRead(b *testing.B, layerCount int, drivername string, d
 		b.Fatal(err)
 	}
 
-	root, err := driver.Get(topLayer, "")
+	root, err := driver.Get(topLayer, "", nil, nil)
 	if err != nil {
 		b.Fatal(err)
 	}

drivers/graphtest/graphtest_unix.go

@@ -99,7 +99,7 @@ func DriverTestCreateEmpty(t testing.TB, drivername string, driverOptions ...str
 		t.Fatal("Newly created image doesn't exist")
 	}
 
-	dir, err := driver.Get("empty", "")
+	dir, err := driver.Get("empty", "", nil, nil)
 	require.NoError(t, err)
 
 	verifyFile(t, dir, 0755|os.ModeDir, 0, 0)
@@ -327,7 +327,7 @@ func DriverTestSetQuota(t *testing.T, drivername string) {
 		t.Fatal(err)
 	}
 
-	mountPath, err := driver.Get("zfsTest", "")
+	mountPath, err := driver.Get("zfsTest", "", nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -357,7 +357,7 @@ func DriverTestEcho(t testing.TB, drivername string, driverOptions ...string) {
 			t.Fatal(err)
 		}
 
-		if root, err = driver.Get(base, ""); err != nil {
+		if root, err = driver.Get(base, "", nil, nil); err != nil {
 			t.Fatal(err)
 		}
 
@@ -392,7 +392,7 @@ func DriverTestEcho(t testing.TB, drivername string, driverOptions ...string) {
 			t.Fatal(err)
 		}
 
-		if root, err = driver.Get(second, ""); err != nil {
+		if root, err = driver.Get(second, "", nil, nil); err != nil {
 			t.Fatal(err)
 		}
 
@@ -418,7 +418,7 @@ func DriverTestEcho(t testing.TB, drivername string, driverOptions ...string) {
 			t.Fatal(err)
 		}
 
-		if root, err = driver.Get(third, ""); err != nil {
+		if root, err = driver.Get(third, "", nil, nil); err != nil {
 			t.Fatal(err)
 		}
 

drivers/graphtest/testutil.go

@@ -30,7 +30,7 @@ func randomContent(size int, seed int64) []byte {
 }
 
 func addFiles(drv graphdriver.Driver, layer string, seed int64) error {
-	root, err := drv.Get(layer, "")
+	root, err := drv.Get(layer, "", nil, nil)
 	if err != nil {
 		return err
 	}
@@ -50,7 +50,7 @@ func addFiles(drv graphdriver.Driver, layer string, seed int64) error {
 }
 
 func checkFile(drv graphdriver.Driver, layer, filename string, content []byte) error {
-	root, err := drv.Get(layer, "")
+	root, err := drv.Get(layer, "", nil, nil)
 	if err != nil {
 		return err
 	}
@@ -69,7 +69,7 @@ func checkFile(drv graphdriver.Driver, layer, filename string, content []byte) e
 }
 
 func addFile(drv graphdriver.Driver, layer, filename string, content []byte) error {
-	root, err := drv.Get(layer, "")
+	root, err := drv.Get(layer, "", nil, nil)
 	if err != nil {
 		return err
 	}
@@ -79,7 +79,7 @@ func addFile(drv graphdriver.Driver, layer, filename string, content []byte) err
 }
 
 func addDirectory(drv graphdriver.Driver, layer, dir string) error {
-	root, err := drv.Get(layer, "")
+	root, err := drv.Get(layer, "", nil, nil)
 	if err != nil {
 		return err
 	}
@@ -89,7 +89,7 @@ func addDirectory(drv graphdriver.Driver, layer, dir string) error {
 }
 
 func removeAll(drv graphdriver.Driver, layer string, names ...string) error {
-	root, err := drv.Get(layer, "")
+	root, err := drv.Get(layer, "", nil, nil)
 	if err != nil {
 		return err
 	}
@@ -104,7 +104,7 @@ func removeAll(drv graphdriver.Driver, layer string, names ...string) error {
 }
 
 func checkFileRemoved(drv graphdriver.Driver, layer, filename string) error {
-	root, err := drv.Get(layer, "")
+	root, err := drv.Get(layer, "", nil, nil)
 	if err != nil {
 		return err
 	}
@@ -120,7 +120,7 @@ func checkFileRemoved(drv graphdriver.Driver, layer, filename string) error {
 }
 
 func addManyFiles(drv graphdriver.Driver, layer string, count int, seed int64) error {
-	root, err := drv.Get(layer, "")
+	root, err := drv.Get(layer, "", nil, nil)
 	if err != nil {
 		return err
 	}
@@ -143,7 +143,7 @@ func addManyFiles(drv graphdriver.Driver, layer string, count int, seed int64) e
 }
 
 func changeManyFiles(drv graphdriver.Driver, layer string, count int, seed int64) ([]archive.Change, error) {
-	root, err := drv.Get(layer, "")
+	root, err := drv.Get(layer, "", nil, nil)
 	if err != nil {
 		return nil, err
 	}
@@ -194,7 +194,7 @@ func changeManyFiles(drv graphdriver.Driver, layer string, count int, seed int64
 }
 
 func checkManyFiles(drv graphdriver.Driver, layer string, count int, seed int64) error {
-	root, err := drv.Get(layer, "")
+	root, err := drv.Get(layer, "", nil, nil)
 	if err != nil {
 		return err
 	}
@@ -248,7 +248,7 @@ func checkChanges(expected, actual []archive.Change) error {
 }
 
 func addLayerFiles(drv graphdriver.Driver, layer, parent string, i int) error {
-	root, err := drv.Get(layer, "")
+	root, err := drv.Get(layer, "", nil, nil)
 	if err != nil {
 		return err
 	}
@@ -289,7 +289,7 @@ func addManyLayers(drv graphdriver.Driver, baseLayer string, count int) (string,
 }
 
 func checkManyLayers(drv graphdriver.Driver, layer string, count int) error {
-	root, err := drv.Get(layer, "")
+	root, err := drv.Get(layer, "", nil, nil)
 	if err != nil {
 		return err
 	}

drivers/graphtest/testutil_unix.go

@@ -40,7 +40,7 @@ func createBase(t testing.TB, driver graphdriver.Driver, name string) {
 	err := driver.CreateReadWrite(name, "", nil)
 	require.NoError(t, err)
 
-	dir, err := driver.Get(name, "")
+	dir, err := driver.Get(name, "", nil, nil)
 	require.NoError(t, err)
 	defer driver.Put(name)
 
@@ -54,7 +54,7 @@ func createBase(t testing.TB, driver graphdriver.Driver, name string) {
 }
 
 func verifyBase(t testing.TB, driver graphdriver.Driver, name string) {
-	dir, err := driver.Get(name, "")
+	dir, err := driver.Get(name, "", nil, nil)
 	require.NoError(t, err)
 	defer driver.Put(name)