Adding kvm-block-migration feature.

I wrote some description the below URL. I hope it may help for reviewing.
<http://etherpad.openstack.org/kvm-block-migration>

Authors

@@ -59,6 +59,7 @@ Joshua McKenty <jmckenty@gmail.com>
 Justin Santa Barbara <justin@fathomdb.com>
 Justin Shepherd <jshepher@rackspace.com>
 Kei Masumoto <masumotok@nttdata.co.jp>
+masumoto<masumotok@nttdata.co.jp>
 Ken Pepple <ken.pepple@gmail.com>
 Kevin Bringard <kbringard@attinteractive.com>
 Kevin L. Mitchell <kevin.mitchell@rackspace.com>

bin/nova-manage

@@ -834,11 +834,13 @@ class VmCommands(object):
                 instance['availability_zone'],
                 instance['launch_index'])
 
-    @args('--ec2_id', dest='ec2_id', metavar='<ec2 id>', help='EC2 ID')
+    def _migration(self, ec2_id, dest, block_migration=False):
-    @args('--dest', dest='dest', metavar='<Destanation>',
+        """Migrates a running instance to a new machine.
-            help='destanation node')
+         :param ec2_id: instance id which comes from euca-describe-instance.
-    def live_migration(self, ec2_id, dest):
+         :param dest: destination host name.
-        """Migrates a running instance to a new machine."""
+         :param block_migration: if True, do block_migration.
+
+        """
 
         ctxt = context.get_admin_context()
         instance_id = ec2utils.ec2_id_to_id(ec2_id)
@@ -859,11 +861,28 @@ class VmCommands(object):
                  {"method": "live_migration",
                   "args": {"instance_id": instance_id,
                            "dest": dest,
-                           "topic": FLAGS.compute_topic}})
+                           "topic": FLAGS.compute_topic,
+                           "block_migration": block_migration}})
 
         print _('Migration of %s initiated.'
                'Check its progress using euca-describe-instances.') % ec2_id
 
+    @args('--ec2_id', dest='ec2_id', metavar='<ec2 id>', help='EC2 ID')
+    @args('--dest', dest='dest', metavar='<Destanation>',
+            help='destanation node')
+    def live_migration(self, ec2_id, dest):
+        """Migrates a running instance to a new machine."""
+
+        self._migration(ec2_id, dest)
+
+    @args('--ec2_id', dest='ec2_id', metavar='<ec2 id>', help='EC2 ID')
+    @args('--dest', dest='dest', metavar='<Destanation>',
+            help='destanation node')
+    def block_migration(self, ec2_id, dest):
+        """Migrates a running instance to a new machine with storage data."""
+
+        self._migration(ec2_id, dest, True)
+
 
 class ServiceCommands(object):
     """Enable and disable running services"""
@@ -945,9 +964,19 @@ class ServiceCommands(object):
             mem_u = result['resource']['memory_mb_used']
             hdd_u = result['resource']['local_gb_used']
 
+            cpu_sum = 0
+            mem_sum = 0
+            hdd_sum = 0
             print 'HOST\t\t\tPROJECT\t\tcpu\tmem(mb)\tdisk(gb)'
             print '%s(total)\t\t\t%s\t%s\t%s' % (host, cpu, mem, hdd)
-            print '%s(used)\t\t\t%s\t%s\t%s' % (host, cpu_u, mem_u, hdd_u)
+            print '%s(used_now)\t\t\t%s\t%s\t%s' % (host, cpu_u, mem_u, hdd_u)
+            for p_id, val in result['usage'].items():
+                cpu_sum += val['vcpus']
+                mem_sum += val['memory_mb']
+                hdd_sum += val['local_gb']
+            print '%s(used_max)\t\t\t%s\t%s\t%s' % (host, cpu_sum,
+                                                    mem_sum, hdd_sum)
+
             for p_id, val in result['usage'].items():
                 print '%s\t\t%s\t\t%s\t%s\t%s' % (host,
                                                   p_id,

nova/tests/test_compute.py

@@ -714,11 +714,15 @@ class ComputeTestCase(test.TestCase):
         dbmock.queue_get_for(c, FLAGS.compute_topic, i_ref['host']).\
                              AndReturn(topic)
         rpc.call(c, topic, {"method": "pre_live_migration",
-                            "args": {'instance_id': i_ref['id']}})
+                            "args": {'instance_id': i_ref['id'],
+                                     'block_migration': False,
+                                     'disk': None}})
+
         self.mox.StubOutWithMock(self.compute.driver, 'live_migration')
         self.compute.driver.live_migration(c, i_ref, i_ref['host'],
                                   self.compute.post_live_migration,
-                                  self.compute.recover_live_migration)
+                                  self.compute.rollback_live_migration,
+                                  False)
 
         self.compute.db = dbmock
         self.mox.ReplayAll()
@@ -739,13 +743,18 @@ class ComputeTestCase(test.TestCase):
         dbmock.queue_get_for(c, FLAGS.compute_topic, i_ref['host']).\
                              AndReturn(topic)
         rpc.call(c, topic, {"method": "pre_live_migration",
-                            "args": {'instance_id': i_ref['id']}}).\
+                            "args": {'instance_id': i_ref['id'],
+                                     'block_migration': False,
+                                     'disk': None}}).\
                             AndRaise(rpc.RemoteError('', '', ''))
         dbmock.instance_update(c, i_ref['id'], {'state_description': 'running',
                                                 'state': power_state.RUNNING,
                                                 'host': i_ref['host']})
         for v in i_ref['volumes']:
             dbmock.volume_update(c, v['id'], {'status': 'in-use'})
+            # mock for volume_api.remove_from_compute
+            rpc.call(c, topic, {"method": "remove_volume",
+                                "args": {'volume_id': v['id']}})
 
         self.compute.db = dbmock
         self.mox.ReplayAll()
@@ -766,7 +775,9 @@ class ComputeTestCase(test.TestCase):
                              AndReturn(topic)
         self.mox.StubOutWithMock(rpc, 'call')
         rpc.call(c, topic, {"method": "pre_live_migration",
-                            "args": {'instance_id': i_ref['id']}}).\
+                            "args": {'instance_id': i_ref['id'],
+                                     'block_migration': False,
+                                     'disk': None}}).\
                             AndRaise(rpc.RemoteError('', '', ''))
         dbmock.instance_update(c, i_ref['id'], {'state_description': 'running',
                                                 'state': power_state.RUNNING,
@@ -791,11 +802,14 @@ class ComputeTestCase(test.TestCase):
         dbmock.queue_get_for(c, FLAGS.compute_topic, i_ref['host']).\
                              AndReturn(topic)
         rpc.call(c, topic, {"method": "pre_live_migration",
-                            "args": {'instance_id': i_ref['id']}})
+                            "args": {'instance_id': i_ref['id'],
+                                     'block_migration': False,
+                                     'disk': None}})
         self.mox.StubOutWithMock(self.compute.driver, 'live_migration')
         self.compute.driver.live_migration(c, i_ref, i_ref['host'],
                                   self.compute.post_live_migration,
-                                  self.compute.recover_live_migration)
+                                  self.compute.rollback_live_migration,
+                                  False)
 
         self.compute.db = dbmock
         self.mox.ReplayAll()
@@ -829,6 +843,10 @@ class ComputeTestCase(test.TestCase):
             self.compute.volume_manager.remove_compute_volume(c, v['id'])
         self.mox.StubOutWithMock(self.compute.driver, 'unfilter_instance')
         self.compute.driver.unfilter_instance(i_ref, [])
+        self.mox.StubOutWithMock(rpc, 'call')
+        rpc.call(c, db.queue_get_for(c, FLAGS.compute_topic, dest),
+            {"method": "post_live_migration_at_destination",
+             "args": {'instance_id': i_ref['id'], 'block_migration': False}})
 
         # executing
         self.mox.ReplayAll()

nova/tests/test_libvirt.py

@@ -21,6 +21,7 @@ import os
 import re
 import shutil
 import sys
+import tempfile
 
 from xml.etree.ElementTree import fromstring as xml_to_tree
 from xml.dom.minidom import parseString as xml_to_dom
@@ -696,17 +697,20 @@ class LibvirtConnTestCase(test.TestCase):
                 return vdmock
 
         self.create_fake_libvirt_mock(lookupByName=fake_lookup)
-        self.mox.StubOutWithMock(self.compute, "recover_live_migration")
+#        self.mox.StubOutWithMock(self.compute, "recover_live_migration")
-        self.compute.recover_live_migration(self.context, instance_ref,
+        self.mox.StubOutWithMock(self.compute, "rollback_live_migration")
-                                            dest='dest')
+#        self.compute.recover_live_migration(self.context, instance_ref,
+#                                             dest='dest')
+        self.compute.rollback_live_migration(self.context, instance_ref,
+                                            'dest', False)
 
-        # Start test
+        #start test
         self.mox.ReplayAll()
         conn = connection.LibvirtConnection(False)
         self.assertRaises(libvirt.libvirtError,
                       conn._live_migration,
-                      self.context, instance_ref, 'dest', '',
+                      self.context, instance_ref, 'dest', False,
-                      self.compute.recover_live_migration)
+                      self.compute.rollback_live_migration)
 
         instance_ref = db.instance_get(self.context, instance_ref['id'])
         self.assertTrue(instance_ref['state_description'] == 'running')
@@ -717,6 +721,95 @@ class LibvirtConnTestCase(test.TestCase):
         db.volume_destroy(self.context, volume_ref['id'])
         db.instance_destroy(self.context, instance_ref['id'])
 
+    def test_pre_block_migration_works_correctly(self):
+        """Confirms pre_block_migration works correctly."""
+
+        # Skip if non-libvirt environment
+        if not self.lazy_load_library_exists():
+            return
+
+        # Replace instances_path since this testcase creates tmpfile
+        tmpdir = tempfile.mkdtemp()
+        store = FLAGS.instances_path
+        FLAGS.instances_path = tmpdir
+
+        # Test data
+        instance_ref = db.instance_create(self.context, self.test_instance)
+        dummyjson = '[{"path": "%s/disk", "local_gb": "10G", "type": "raw"}]'
+
+        # Preparing mocks
+        # qemu-img should be mockd since test environment might not have
+        # large disk space.
+        self.mox.StubOutWithMock(utils, "execute")
+        utils.execute('sudo', 'qemu-img', 'create', '-f', 'raw',
+                      '%s/%s/disk' % (tmpdir, instance_ref.name), '10G')
+
+        self.mox.ReplayAll()
+        conn = connection.LibvirtConnection(False)
+        conn.pre_block_migration(self.context, instance_ref,
+                                 dummyjson % tmpdir)
+
+        self.assertTrue(os.path.exists('%s/%s/' %
+                                       (tmpdir, instance_ref.name)))
+
+        shutil.rmtree(tmpdir)
+        db.instance_destroy(self.context, instance_ref['id'])
+        # Restore FLAGS.instances_path
+        FLAGS.instances_path = store
+
+    def test_get_instance_disk_info_works_correctly(self):
+        """Confirms pre_block_migration works correctly."""
+        # Skip if non-libvirt environment
+        if not self.lazy_load_library_exists():
+            return
+
+        # Test data
+        instance_ref = db.instance_create(self.context, self.test_instance)
+        dummyxml = ("<domain type='kvm'><name>instance-0000000a</name>"
+                    "<devices>"
+                    "<disk type='file'><driver name='qemu' type='raw'/>"
+                    "<source file='/test/disk'/>"
+                    "<target dev='vda' bus='virtio'/></disk>"
+                    "<disk type='file'><driver name='qemu' type='qcow2'/>"
+                    "<source file='/test/disk.local'/>"
+                    "<target dev='vdb' bus='virtio'/></disk>"
+                    "</devices></domain>")
+
+        ret = ("image: /test/disk\nfile format: raw\n"
+               "virtual size: 20G (21474836480 bytes)\ndisk size: 3.1G\n")
+
+        # Preparing mocks
+        vdmock = self.mox.CreateMock(libvirt.virDomain)
+        self.mox.StubOutWithMock(vdmock, "XMLDesc")
+        vdmock.XMLDesc(0).AndReturn(dummyxml)
+
+        def fake_lookup(instance_name):
+            if instance_name == instance_ref.name:
+                return vdmock
+        self.create_fake_libvirt_mock(lookupByName=fake_lookup)
+
+        self.mox.StubOutWithMock(os.path, "getsize")
+        # based on above testdata, one is raw image, so getsize is mocked.
+        os.path.getsize("/test/disk").AndReturn(10 * 1024 * 1024 * 1024)
+        # another is qcow image, so qemu-img should be mocked.
+        self.mox.StubOutWithMock(utils, "execute")
+        utils.execute('sudo', 'qemu-img', 'info', '/test/disk.local').\
+            AndReturn((ret, ''))
+
+        self.mox.ReplayAll()
+        conn = connection.LibvirtConnection(False)
+        info = conn.get_instance_disk_info(self.context, instance_ref)
+        info = utils.loads(info)
+
+        self.assertTrue(info[0]['type'] == 'raw' and
+                        info[1]['type'] == 'qcow2' and
+                        info[0]['path'] == '/test/disk' and
+                        info[1]['path'] == '/test/disk.local' and
+                        info[0]['local_gb'] == '10G' and
+                        info[1]['local_gb'] == '20G')
+
+        db.instance_destroy(self.context, instance_ref['id'])
+
     def test_spawn_with_network_info(self):
         # Skip if non-libvirt environment
         if not self.lazy_load_library_exists():