ostree: new storage

Skopeo needs a bugfix from:

containers/image#305

which is not merged yet.  Just apply this patch:

diff --git a/vendor/github.com/containers/image/storage/storage_image.go b/vendor/github.com/containers/image/storage/storage_image.go
index 08fa71b..5edccce 100644
--- a/vendor/github.com/containers/image/storage/storage_image.go
+++ b/vendor/github.com/containers/image/storage/storage_image.go
@@ -174,7 +174,7 @@ func (s *storageImageDestination) putBlob(stream io.Reader, blobinfo types.BlobI
                        id = ddigest.Canonical.FromBytes([]byte(parentLayer + "+" + digest.String())).Hex()
                }
                // Attempt to create the identified layer and import its contents.
-               layer, uncompressedSize, err := s.imageRef.transport.store.PutLayer(id, parentLayer, nil, "", true, multi)
+               layer, uncompressedSize, err := s.imageRef.transport.store.PutLayer(id, parentLayer, nil, "", false, multi)
                if err != nil && errors.Cause(err) != storage.ErrDuplicateID {
                        logrus.Debugf("error importing layer blob %q as %q: %v", blobinfo.Digest, id, err)
                        return errorBlobInfo, err

Signed-off-by: Giuseppe Scrivano <[email protected]>

.travis.yml

@@ -5,10 +5,12 @@ go:
     - 1.7
 dist: trusty
 sudo: required
+env:
+  - TAGS='exclude_graphdriver_ostree'
 before_install:
     - sudo apt-get -qq update
     - sudo apt-get -qq install btrfs-tools libdevmapper-dev
 script:
     - make install.tools
     - make local-binary docs local-cross local-validate
-    - sudo PATH="$PATH" make local-test-unit local-test-integration
+    - sudo -E PATH="$PATH" make local-test-unit local-test-integration

drivers/driver_linux.go

@@ -59,6 +59,7 @@ var (
 		"btrfs",
 		"zfs",
 		"vfs",
+		"ostree",
 	}
 
 	// FsNames maps filesystem id to name of the filesystem.

drivers/ostree/driver.go

@@ -0,0 +1,179 @@
+// +build !exclude_graphdriver_ostree
+
+package ostree
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/containers/storage/drivers"
+	"github.com/containers/storage/drivers/overlay"
+	"github.com/containers/storage/pkg/idtools"
+	"github.com/containers/storage/pkg/system"
+	"github.com/ostreedev/ostree-go/pkg/otbuiltin"
+	"github.com/pkg/errors"
+)
+
+func init() {
+	graphdriver.Register("ostree", Init)
+}
+
+// Init returns a new OSTREE driver.
+// This sets the home directory for the driver and returns NaiveDiffDriver.
+func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
+	overlay, err := overlay.Init(home, options, uidMaps, gidMaps)
+	if err != nil {
+		return nil, err
+	}
+
+	repoLocation := filepath.Join(home, ".repo")
+	for _, option := range options {
+		if strings.HasPrefix(option, "ostree.repo=") {
+			repoLocation = option[12:]
+		}
+	}
+
+	_, err = os.Stat(repoLocation)
+	if err != nil && !os.IsNotExist(err) {
+		return nil, err
+	} else if err != nil {
+		idMappings := idtools.NewIDMappingsFromMaps(uidMaps, gidMaps)
+		rootIDs := idMappings.RootPair()
+		if err := idtools.MkdirAllAndChown(repoLocation, 0700, rootIDs); err != nil {
+			return nil, errors.Wrap(err, "could not create OSTree repository directory: %v")
+		}
+
+		if err := exec.Command("ostree", fmt.Sprintf("--repo=%s", repoLocation), "init").Run(); err != nil {
+			return nil, errors.Wrap(err, "could not create OSTree repository")
+		}
+	}
+
+	repo, err := otbuiltin.OpenRepo(repoLocation)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not open the OSTree repository")
+	}
+
+	d := &Driver{
+		home:    home,
+		overlay: overlay,
+		convert: make(map[string]bool),
+	}
+	d.repo = repo
+	d.repoLocation = repoLocation
+	return graphdriver.NewNaiveDiffDriver(d, uidMaps, gidMaps), nil
+}
+
+// Driver must be wrapped in NaiveDiffDriver to be used as a graphdriver.Driver
+type Driver struct {
+	home         string
+	overlay      graphdriver.Driver
+	repo         *otbuiltin.Repo
+	repoLocation string
+	convert      map[string]bool
+}
+
+func (d *Driver) String() string {
+	return "ostree"
+}
+
+// Status is used for implementing the graphdriver.ProtoDriver interface. OSTREE does not currently have any status information.
+func (d *Driver) Status() [][2]string {
+	return d.overlay.Status()
+}
+
+// Metadata is used for implementing the graphdriver.ProtoDriver interface. OSTREE does not currently have any meta data.
+func (d *Driver) Metadata(id string) (map[string]string, error) {
+	return d.overlay.Metadata(id)
+}
+
+// Cleanup is used to implement graphdriver.ProtoDriver. There is no cleanup required for this driver.
+func (d *Driver) Cleanup() error {
+	return d.overlay.Cleanup()
+}
+
+// CreateReadWrite creates a layer that is writable for use as a container
+// file system.
+func (d *Driver) CreateReadWrite(id, parent string, opts *graphdriver.CreateOpts) error {
+	return d.overlay.CreateReadWrite(id, parent, opts)
+}
+
+// Create prepares the filesystem for the OSTREE driver and copies the directory for the given id under the parent.
+func (d *Driver) Create(id, parent string, opts *graphdriver.CreateOpts) error {
+	d.convert[id] = true
+	return d.overlay.Create(id, parent, opts)
+}
+
+func getDir(home, id string) string {
+	return filepath.Join(home, id, "diff")
+}
+
+// Create prepares the filesystem for the OSTREE driver and copies the directory for the given id under the parent.
+func (d *Driver) convertToOSTree(root, id string) error {
+	if _, err := d.repo.PrepareTransaction(); err != nil {
+		return errors.Wrap(err, "could not prepare the OSTree transaction")
+	}
+
+	commitOpts := otbuiltin.NewCommitOptions()
+	commitOpts.Timestamp = time.Now()
+	commitOpts.Parent = "0000000000000000000000000000000000000000000000000000000000000000"
+	branch := fmt.Sprintf("ocilayer/%s", id)
+
+	if _, err := d.repo.Commit(root, branch, commitOpts); err != nil {
+		return errors.Wrap(err, "could not commit the layer")
+	}
+
+	if _, err := d.repo.CommitTransaction(); err != nil {
+		return errors.Wrap(err, "could not complete the OSTree transaction")
+	}
+
+	if err := system.EnsureRemoveAll(root); err != nil {
+		return err
+	}
+
+	checkoutOpts := otbuiltin.NewCheckoutOptions()
+	if err := otbuiltin.Checkout(d.repoLocation, root, branch, checkoutOpts); err != nil {
+		return errors.Wrap(err, "could not checkout from OSTree")
+	}
+	return nil
+}
+
+// Remove deletes the content from the directory for a given id.
+func (d *Driver) Remove(id string) error {
+	branch := fmt.Sprintf("ocilayer/%s", id)
+	if err := exec.Command("ostree", fmt.Sprintf("--repo=%s", d.repoLocation), "refs", "--delete", branch).Run(); err != nil {
+		return errors.Wrap(err, "could not delete OSTree branch")
+	}
+	return nil
+}
+
+// Get returns the directory for the given id.
+func (d *Driver) Get(id, mountLabel string) (string, error) {
+	return d.overlay.Get(id, mountLabel)
+}
+
+func (d *Driver) Put(id string) error {
+	root := getDir(d.home, id)
+
+	_, convert := d.convert[id]
+	if convert {
+		if err := d.convertToOSTree(root, id); err != nil {
+			return err
+		}
+	}
+
+	return d.overlay.Put(id)
+}
+
+// Exists checks to see if the directory exists for the given id.
+func (d *Driver) Exists(id string) bool {
+	return d.overlay.Exists(id)
+}
+
+// AdditionalImageStores returns additional image stores supported by the driver
+func (d *Driver) AdditionalImageStores() []string {
+	return d.overlay.AdditionalImageStores()
+}

drivers/ostree/driver_stub.go

@@ -0,0 +1,19 @@
+// +build exclude_graphdriver_ostree
+
+package ostree
+
+import (
+	"fmt"
+
+	"github.com/containers/storage/drivers"
+	"github.com/containers/storage/pkg/idtools"
+	"github.com/pkg/errors"
+)
+
+func init() {
+	graphdriver.Register("ostree", Init)
+}
+
+func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
+	return nil, errors.Errorf(" THIS ostree driver not supported")
+}

drivers/register/register_ostree.go

@@ -0,0 +1,8 @@
+// +build !exclude_graphdriver_ostree
+
+package register
+
+import (
+	// register the ostree graphdriver
+	_ "github.com/containers/storage/drivers/ostree"
+)