[ZFSonLinux] Add 'manage snapshot' feature support

Implement 'manage snapshot' feature in ZFSonLinux share driver.

Prerequisites:
- snapshot being managed should exist.

Details:
- snapshot being managed will be renamed by share driver based on
  taken ID.
- size for managed snapshot will be taken either from
  REST API (--driver_options size=5) or
  from its "used" attribute.

Implements BP zfsonlinux-manage-snapshot
DocImpact

Change-Id: If240ecde5676c334d39faaccd5703e93544aaa06
Depends-On: Ifc762a882a78159adacfe168a4edbe824178301a

contrib/ci/post_test_hook.sh

@@ -171,6 +171,7 @@ elif [[ "$DRIVER" == "zfsonlinux" ]]; then
     MANILA_TEMPEST_CONCURRENCY=8
     RUN_MANILA_CG_TESTS=False
     RUN_MANILA_MANAGE_TESTS=True
+    RUN_MANILA_MANAGE_SNAPSHOT_TESTS=True
     iniset $TEMPEST_CONFIG share run_migration_tests False
     iniset $TEMPEST_CONFIG share run_quota_tests True
     iniset $TEMPEST_CONFIG share run_replication_tests True

doc/source/devref/share_back_ends_feature_support_mapping.rst

@@ -33,7 +33,7 @@ Mapping of share drivers and share features support
 +----------------------------------------+-----------------------+-----------------------+--------------+--------------+------------------------+----------------------------+--------------------------+
 |               Driver name              | create delete share   | manage unmanage share | extend share | shrink share | create delete snapshot | create share from snapshot | manage unmanage snapshot |
 +========================================+=======================+=======================+==============+==============+========================+============================+==========================+
-|               ZFSonLinux               |           M           |           N           |       M      |       M      |            M           |              M             |            \-            |
+|               ZFSonLinux               |           M           |           N           |       M      |       M      |            M           |              M             |            N             |
 +----------------------------------------+-----------------------+-----------------------+--------------+--------------+------------------------+----------------------------+--------------------------+
 |      Generic (Cinder as back-end)      |           J           |           K           |       L      |       L      |            J           |              J             |            M             |
 +----------------------------------------+-----------------------+-----------------------+--------------+--------------+------------------------+----------------------------+--------------------------+

doc/source/devref/zfs_on_linux_driver.rst

@@ -48,6 +48,8 @@ The following operations are supported:
 * Deny NFS Share access
 * Create snapshot
 * Delete snapshot
+* Manage snapshot
+* Unmanage snapshot
 * Create share from snapshot
 * Extend share
 * Shrink share

manila/share/drivers/zfsonlinux/driver.py

@@ -18,6 +18,7 @@ Module with ZFSonLinux share driver that utilizes ZFS filesystem resources
 and exports them as shares.
 """
 
+import math
 import time
 
 from oslo_config import cfg
@@ -492,6 +493,7 @@ class ZFSonLinuxShareDriver(zfs_utils.ExecuteMixin, driver.ShareDriver):
             }
         )
         self.zfs('snapshot', snapshot_name)
+        return {"provider_location": snapshot_name}
 
     @ensure_share_server_not_provided
     def delete_snapshot(self, context, snapshot, share_server=None):
@@ -519,7 +521,7 @@ class ZFSonLinuxShareDriver(zfs_utils.ExecuteMixin, driver.ShareDriver):
                 _LW("Snapshot with '%(id)s' ID and '%(name)s' NAME is "
                     "absent on backend. Nothing has been deleted."),
                 {'id': snapshot['id'], 'name': snapshot_name})
-        self.private_storage.delete(snapshot['id'])
+        self.private_storage.delete(snapshot['snapshot_id'])
 
     @ensure_share_server_not_provided
     def create_share_from_snapshot(self, context, share, snapshot,
@@ -723,6 +725,54 @@ class ZFSonLinuxShareDriver(zfs_utils.ExecuteMixin, driver.ShareDriver):
         """Removes the specified share from Manila management."""
         self.private_storage.delete(share['id'])
 
+    def manage_existing_snapshot(self, snapshot_instance, driver_options):
+        """Manage existing share snapshot with manila.
+
+        :param snapshot_instance: SnapshotInstance data
+        :param driver_options: expects only one optional key 'size'.
+        :return: dict with share snapshot instance fields for update, example:
+            {'size': 1,
+             'provider_location': 'path/to/some/dataset@some_snapshot_tag'}
+        """
+        snapshot_size = int(driver_options.get("size", 0))
+        old_provider_location = snapshot_instance.get("provider_location")
+        old_snapshot_tag = old_provider_location.split("@")[-1]
+        new_snapshot_tag = self._get_snapshot_name(snapshot_instance["id"])
+
+        self.private_storage.update(
+            snapshot_instance["snapshot_id"], {
+                "entity_type": "snapshot",
+                "old_snapshot_tag": old_snapshot_tag,
+                "snapshot_tag": new_snapshot_tag,
+            }
+        )
+
+        try:
+            self.zfs("list", "-r", "-t", "snapshot", old_provider_location)
+        except exception.ProcessExecutionError as e:
+            raise exception.ManageInvalidShareSnapshot(reason=e.stderr)
+
+        if not snapshot_size:
+            consumed_space = self.get_zfs_option(old_provider_location, "used")
+            consumed_space = utils.translate_string_size_to_float(
+                consumed_space)
+            snapshot_size = int(math.ceil(consumed_space))
+
+        dataset_name = self.private_storage.get(
+            snapshot_instance["share_instance_id"], "dataset_name")
+        new_provider_location = dataset_name + "@" + new_snapshot_tag
+
+        self.zfs("rename", old_provider_location, new_provider_location)
+
+        return {
+            "size": snapshot_size,
+            "provider_location": new_provider_location,
+        }
+
+    def unmanage_snapshot(self, snapshot_instance):
+        """Unmanage dataset snapshot."""
+        self.private_storage.delete(snapshot_instance["snapshot_id"])
+
     def _get_replication_snapshot_prefix(self, replica):
         """Returns replica-based snapshot prefix."""
         replication_snapshot_prefix = "%s_%s" % (

manila/tests/share/drivers/zfsonlinux/test_driver.py

@@ -632,7 +632,7 @@ class ZFSonLinuxShareDriverTestCase(test.TestCase):
             snapshot['share_instance_id'],
             {'dataset_name': 'foo_data_set_name'})
 
-        self.driver.create_snapshot('fake_context', snapshot)
+        result = self.driver.create_snapshot('fake_context', snapshot)
 
         self.driver.zfs.assert_called_once_with(
             'snapshot', snapshot_name)
@@ -640,6 +640,7 @@ class ZFSonLinuxShareDriverTestCase(test.TestCase):
             snapshot_name.split('@')[-1],
             self.driver.private_storage.get(
                 snapshot['snapshot_id'], 'snapshot_tag'))
+        self.assertEqual({"provider_location": snapshot_name}, result)
 
     def test_delete_snapshot(self):
         snapshot = {
@@ -1194,6 +1195,89 @@ class ZFSonLinuxShareDriverTestCase(test.TestCase):
 
         self.driver.private_storage.delete.assert_called_once_with(share['id'])
 
+    @ddt.data(
+        {},
+        {"size": 5},
+        {"size": "5"},
+    )
+    def test_manage_existing_snapshot(self, driver_options):
+        dataset_name = "path/to/dataset"
+        old_provider_location = dataset_name + "@original_snapshot_tag"
+        snapshot_instance = {
+            "id": "fake_snapshot_instance_id",
+            "share_instance_id": "fake_share_instance_id",
+            "snapshot_id": "fake_snapshot_id",
+            "provider_location": old_provider_location,
+        }
+        new_snapshot_tag = "fake_new_snapshot_tag"
+        new_provider_location = (
+            old_provider_location.split("@")[0] + "@" + new_snapshot_tag)
+
+        self.mock_object(self.driver, "zfs")
+        self.mock_object(
+            self.driver, "get_zfs_option", mock.Mock(return_value="5G"))
+        self.mock_object(
+            self.driver,
+            '_get_snapshot_name',
+            mock.Mock(return_value=new_snapshot_tag))
+        self.driver.private_storage.update(
+            snapshot_instance["share_instance_id"],
+            {"dataset_name": dataset_name})
+
+        result = self.driver.manage_existing_snapshot(
+            snapshot_instance, driver_options)
+
+        expected_result = {
+            "size": 5,
+            "provider_location": new_provider_location,
+        }
+        self.assertEqual(expected_result, result)
+        self.driver._get_snapshot_name.assert_called_once_with(
+            snapshot_instance["id"])
+        self.driver.zfs.assert_has_calls([
+            mock.call("list", "-r", "-t", "snapshot", old_provider_location),
+            mock.call("rename", old_provider_location, new_provider_location),
+        ])
+
+    def test_manage_existing_snapshot_not_found(self):
+        dataset_name = "path/to/dataset"
+        old_provider_location = dataset_name + "@original_snapshot_tag"
+        new_snapshot_tag = "fake_new_snapshot_tag"
+        snapshot_instance = {
+            "id": "fake_snapshot_instance_id",
+            "snapshot_id": "fake_snapshot_id",
+            "provider_location": old_provider_location,
+        }
+        self.mock_object(
+            self.driver, "_get_snapshot_name",
+            mock.Mock(return_value=new_snapshot_tag))
+        self.mock_object(
+            self.driver, "zfs",
+            mock.Mock(side_effect=exception.ProcessExecutionError("FAKE")))
+
+        self.assertRaises(
+            exception.ManageInvalidShareSnapshot,
+            self.driver.manage_existing_snapshot,
+            snapshot_instance, {},
+        )
+
+        self.driver.zfs.assert_called_once_with(
+            "list", "-r", "-t", "snapshot", old_provider_location)
+        self.driver._get_snapshot_name.assert_called_once_with(
+            snapshot_instance["id"])
+
+    def test_unmanage_snapshot(self):
+        snapshot_instance = {
+            "id": "fake_snapshot_instance_id",
+            "snapshot_id": "fake_snapshot_id",
+        }
+        self.mock_object(self.driver.private_storage, "delete")
+
+        self.driver.unmanage_snapshot(snapshot_instance)
+
+        self.driver.private_storage.delete.assert_called_once_with(
+            snapshot_instance["snapshot_id"])
+
     def test__delete_dataset_or_snapshot_with_retry_snapshot(self):
         self.mock_object(self.driver, 'get_zfs_option')
         self.mock_object(self.driver, 'zfs')

releasenotes/notes/manage-snapshot-in-zfsonlinux-driver-6478d8d5b3c6a97f.yaml

@@ -0,0 +1,3 @@
+---
+features:
+  - Added support of 'manage snapshot' feature to ZFSonLinux driver.