z/VM Driver: add snapshot function

This patch add snapshot function to z/VM driver, it will call
underlying zvmsdk to generate the image

Change-Id: I0409aba55487e92efa6370eed41936bf8a4ef25d
blueprint: add-zvm-driver-rocky

nova/tests/unit/virt/zvm/test_driver.py

@@ -14,6 +14,8 @@
 
 import copy
 import mock
+import os
+import six
 
 from nova import conf
 from nova import context
@@ -118,6 +120,8 @@ class TestZVMDriver(test.NoDBTestCase):
                 network_model.VIF(**self._network_values)
         ])
 
+        self.mock_update_task_state = mock.Mock()
+
     def test_driver_init_no_url(self):
         self.flags(cloud_connector_url=None, group='zvm')
         self.assertRaises(exception.ZVMDriverException,
@@ -324,3 +328,128 @@ class TestZVMDriver(test.NoDBTestCase):
                           injected_files=None, admin_password=None,
                           allocations=None, network_info=self._network_info,
                           block_device_info=None)
+
+    @mock.patch.object(six.moves.builtins, 'open')
+    @mock.patch('nova.image.glance.get_remote_image_service')
+    @mock.patch('nova.virt.zvm.utils.ConnectorClient.call')
+    def test_snapshot(self, call, get_image_service, mock_open):
+        image_service = mock.Mock()
+        image_id = 'e9ee1562-3ea1-4cb1-9f4c-f2033000eab1'
+        get_image_service.return_value = (image_service, image_id)
+        call_resp = ['', {"os_version": "rhel7.2",
+                          "dest_url": "file:///path/to/target"}, '']
+        call.side_effect = call_resp
+        new_image_meta = {
+            'is_public': False,
+            'status': 'active',
+            'properties': {
+                 'image_location': 'snapshot',
+                 'image_state': 'available',
+                 'owner_id': self._instance['project_id'],
+                 'os_distro': call_resp[1]['os_version'],
+                 'architecture': 's390x',
+                 'hypervisor_type': 'zvm'
+            },
+            'disk_format': 'raw',
+            'container_format': 'bare',
+        }
+        image_path = os.path.join(os.path.normpath(
+                            CONF.zvm.image_tmp_path), image_id)
+        dest_path = "file://" + image_path
+
+        self._driver.snapshot(self._context, self._instance, image_id,
+                              self.mock_update_task_state)
+        get_image_service.assert_called_with(self._context, image_id)
+
+        mock_open.assert_called_once_with(image_path, 'r')
+        ret_file = mock_open.return_value.__enter__.return_value
+        image_service.update.assert_called_once_with(self._context,
+                                                     image_id,
+                                                     new_image_meta,
+                                                     ret_file,
+                                                     purge_props=False)
+        self.mock_update_task_state.assert_has_calls([
+            mock.call(task_state='image_pending_upload'),
+            mock.call(expected_state='image_pending_upload',
+                      task_state='image_uploading')
+        ])
+        call.assert_has_calls([
+            mock.call('guest_capture', self._instance.name, image_id),
+            mock.call('image_export', image_id, dest_path,
+                      remote_host=mock.ANY),
+            mock.call('image_delete', image_id)
+        ])
+
+    @mock.patch('nova.image.glance.get_remote_image_service')
+    @mock.patch('nova.virt.zvm.hypervisor.Hypervisor.guest_capture')
+    def test_snapshot_capture_fail(self, mock_capture, get_image_service):
+        image_service = mock.Mock()
+        image_id = 'e9ee1562-3ea1-4cb1-9f4c-f2033000eab1'
+        get_image_service.return_value = (image_service, image_id)
+        mock_capture.side_effect = exception.ZVMDriverException(error='error')
+
+        self.assertRaises(exception.ZVMDriverException, self._driver.snapshot,
+                          self._context, self._instance, image_id,
+                          self.mock_update_task_state)
+
+        self.mock_update_task_state.assert_called_once_with(
+            task_state='image_pending_upload')
+        image_service.delete.assert_called_once_with(self._context, image_id)
+
+    @mock.patch('nova.image.glance.get_remote_image_service')
+    @mock.patch('nova.virt.zvm.utils.ConnectorClient.call')
+    @mock.patch('nova.virt.zvm.hypervisor.Hypervisor.image_delete')
+    @mock.patch('nova.virt.zvm.hypervisor.Hypervisor.image_export')
+    def test_snapshot_import_fail(self, mock_import, mock_delete,
+                                  call, get_image_service):
+        image_service = mock.Mock()
+        image_id = 'e9ee1562-3ea1-4cb1-9f4c-f2033000eab1'
+        get_image_service.return_value = (image_service, image_id)
+
+        mock_import.side_effect = exception.ZVMDriverException(error='error')
+
+        self.assertRaises(exception.ZVMDriverException, self._driver.snapshot,
+                          self._context, self._instance, image_id,
+                          self.mock_update_task_state)
+
+        self.mock_update_task_state.assert_called_once_with(
+            task_state='image_pending_upload')
+        get_image_service.assert_called_with(self._context, image_id)
+        call.assert_called_once_with('guest_capture',
+                                     self._instance.name, image_id)
+        mock_delete.assert_called_once_with(image_id)
+        image_service.delete.assert_called_once_with(self._context, image_id)
+
+    @mock.patch.object(six.moves.builtins, 'open')
+    @mock.patch('nova.image.glance.get_remote_image_service')
+    @mock.patch('nova.virt.zvm.utils.ConnectorClient.call')
+    @mock.patch('nova.virt.zvm.hypervisor.Hypervisor.image_delete')
+    @mock.patch('nova.virt.zvm.hypervisor.Hypervisor.image_export')
+    def test_snapshot_update_fail(self, mock_import, mock_delete, call,
+                                  get_image_service, mock_open):
+        image_service = mock.Mock()
+        image_id = 'e9ee1562-3ea1-4cb1-9f4c-f2033000eab1'
+        get_image_service.return_value = (image_service, image_id)
+        image_service.update.side_effect = exception.ImageNotAuthorized(
+            image_id='dummy')
+        image_path = os.path.join(os.path.normpath(
+                            CONF.zvm.image_tmp_path), image_id)
+
+        self.assertRaises(exception.ImageNotAuthorized, self._driver.snapshot,
+                          self._context, self._instance, image_id,
+                          self.mock_update_task_state)
+
+        mock_open.assert_called_once_with(image_path, 'r')
+
+        get_image_service.assert_called_with(self._context, image_id)
+        mock_delete.assert_called_once_with(image_id)
+        image_service.delete.assert_called_once_with(self._context, image_id)
+
+        self.mock_update_task_state.assert_has_calls([
+            mock.call(task_state='image_pending_upload'),
+            mock.call(expected_state='image_pending_upload',
+                      task_state='image_uploading')
+        ])
+
+        call.assert_called_once_with('guest_capture', self._instance.name,
+                                     image_id)

nova/tests/unit/virt/zvm/test_hypervisor.py

@@ -97,3 +97,19 @@ class TestZVMHypervisor(test.NoDBTestCase):
         instance = fake_instance.fake_instance_obj(self._context)
         res = self._hypervisor.guest_exists(instance)
         self.assertFalse(res)
+
+    @mock.patch('nova.virt.zvm.utils.ConnectorClient.call')
+    def test_guest_capture(self, mcall):
+        self._hypervisor.guest_capture('n1', 'image-id')
+        mcall.assert_called_once_with('guest_capture', 'n1', 'image-id')
+
+    @mock.patch('nova.virt.zvm.utils.ConnectorClient.call')
+    def test_image_export(self, mcall):
+        self._hypervisor.image_export('image-id', 'path')
+        mcall.assert_called_once_with('image_export', 'image-id', 'path',
+                                      remote_host=self._hypervisor._rhost)
+
+    @mock.patch('nova.virt.zvm.utils.ConnectorClient.call')
+    def test_image_delete(self, mcall):
+        self._hypervisor.image_delete('image-id')
+        mcall.assert_called_once_with('image_delete', 'image-id')

nova/virt/zvm/driver.py

@@ -22,9 +22,11 @@ from oslo_log import log as logging
 from oslo_serialization import jsonutils
 from oslo_utils import excutils
 
+from nova.compute import task_states
 from nova import conf
 from nova import exception
 from nova.i18n import _
+from nova.image import glance
 from nova.objects import fields as obj_fields
 from nova import utils
 from nova.virt import driver
@@ -299,3 +301,68 @@ class ZVMDriver(driver.ComputeDriver):
 
     def get_host_uptime(self):
         return self._hypervisor.get_host_uptime()
+
+    def snapshot(self, context, instance, image_id, update_task_state):
+
+        (image_service, image_id) = glance.get_remote_image_service(
+                                                    context, image_id)
+
+        update_task_state(task_state=task_states.IMAGE_PENDING_UPLOAD)
+
+        try:
+            self._hypervisor.guest_capture(instance.name, image_id)
+        except Exception as err:
+            with excutils.save_and_reraise_exception():
+                LOG.error("Failed to capture the instance "
+                          "to generate an image with reason: %(err)s",
+                          {'err': err}, instance=instance)
+                # Clean up the image from glance
+                image_service.delete(context, image_id)
+
+        # Export the image to nova-compute server temporary
+        image_path = os.path.join(os.path.normpath(
+                            CONF.zvm.image_tmp_path), image_id)
+        dest_path = "file://" + image_path
+        try:
+            resp = self._hypervisor.image_export(image_id, dest_path)
+        except Exception:
+            with excutils.save_and_reraise_exception():
+                LOG.error("Failed to export image %s from SDK server to "
+                          "nova compute server", image_id)
+                image_service.delete(context, image_id)
+                self._hypervisor.image_delete(image_id)
+
+        # Save image to glance
+        new_image_meta = {
+            'is_public': False,
+            'status': 'active',
+            'properties': {
+                 'image_location': 'snapshot',
+                 'image_state': 'available',
+                 'owner_id': instance['project_id'],
+                 'os_distro': resp['os_version'],
+                 'architecture': obj_fields.Architecture.S390X,
+                 'hypervisor_type': obj_fields.HVType.ZVM,
+            },
+            'disk_format': 'raw',
+            'container_format': 'bare',
+        }
+        update_task_state(task_state=task_states.IMAGE_UPLOADING,
+                          expected_state=task_states.IMAGE_PENDING_UPLOAD)
+
+        # Save the image to glance
+        try:
+            with open(image_path, 'r') as image_file:
+                image_service.update(context,
+                                     image_id,
+                                     new_image_meta,
+                                     image_file,
+                                     purge_props=False)
+        except Exception:
+            with excutils.save_and_reraise_exception():
+                image_service.delete(context, image_id)
+        finally:
+            zvmutils.clean_up_file(image_path)
+            self._hypervisor.image_delete(image_id)
+
+        LOG.debug("Snapshot image upload complete", instance=instance)

nova/virt/zvm/hypervisor.py

@@ -124,6 +124,9 @@ class Hypervisor(object):
     def guest_config_minidisks(self, name, disk_list):
         self._reqh.call('guest_config_minidisks', name, disk_list)
 
+    def guest_capture(self, name, image_id):
+        self._reqh.call('guest_capture', name, image_id)
+
     def image_query(self, imagename):
         """Check whether image is there or not
 
@@ -142,3 +145,15 @@ class Hypervisor(object):
     def image_import(self, image_href, image_url, image_meta):
         self._reqh.call('image_import', image_href, image_url,
                         image_meta, remote_host=self._rhost)
+
+    def image_export(self, image_id, dest_path):
+        """export image to a given place
+
+        :returns: a dict which represent the exported image information.
+        """
+        resp = self._reqh.call('image_export', image_id,
+                               dest_path, remote_host=self._rhost)
+        return resp
+
+    def image_delete(self, image_id):
+        self._reqh.call('image_delete', image_id)

nova/virt/zvm/utils.py

@@ -119,3 +119,8 @@ def generate_configdrive(context, instance, injected_files,
                                               network_info,
                                               admin_password)
     return transportfiles
+
+
+def clean_up_file(filepath):
+    if os.path.exists(filepath):
+        os.remove(filepath)