Unbreak start instance and fixes bug 905270

This patch fixes the bug 905270
https://bugs.launchpad.net/nova/+bug/905270

According to EC2 documentation, EBS-instances that initiated shutdown
 result in stopped state.  And then it can be started again.  (On the
 other hand non-EBS instance result in terminted when instance
 initiated shutdown)

However, the current nova case, the shutdowned instance always results
 in terminated status.  As related issues are
 - describe-instance-attribute instance_initiated_shutdown_behavior doesn't
   work correctly
 - instance attribute disable_api_termination isn't supported
 - stop instance was broken by the change set of the following.
   It needs unbreak.

  > commit eb03d47fecd3bfc24243da29ee01679b334a08fe
  >  Author: Vishvananda Ishaya <vishvananda@gmail.com>
  >  Date: Fri Sep 23 09:22:32 2011 -0700
  >
  >    Remove AoE, Clean up volume code
  >
  >     * Removes Ata Over Ethernet
  >     * Adds drivers to libvirt for volumes
  >     * Adds initialize_connection and terminate_connection to volume api
  >     * Passes connection info back through volume api
  >
  >  Change-Id: I1b1626f40bebe8466ab410fb174683293c7c474f

This patch
- unbreak start instance
- implement instance_initiated_shutdown_behavior and make it EC2 compatible
- implement disable_api_termination

---
Changes 5 -> 6:
- fixes to catch up 26b7b9457a5899ecca93fd67d3879efcad4e4968

Changes 4 -> 5:
- HACKING compilance

Changes 3 -> 4:
- rebased to 4c5586a28fd7a085369c49f6039876ffdc86b526
  sqlalchemy migrate version

Changes 2 -> 3:
- rename long name to shorter one
  s/instance_initiated_shutdown_behavior/shutdown_terminate/g
  s/disable_api_termination/disable_terminate/g
  as suggested Kevin L. Mitchell
- improved nova.api.ec2.cloud._state_description
- pep8
- broken out patches are available for easy review at
  git://github.com/yamahata/nova.git lp905270-2

Changes 1 -> 2:
- fixed an unit test failure pointed out by Mark.
  (I think ebtabls failure strongly suggests installation problem)
- introduce vm_states.SHUTOFF and put instance state which is in
  power_state.{NOSTATE, SHUTOFF} into vm_states.SHUTOFF.
- simplified logic a bit by vm_states.SHUTOFF as suggested by Vish.
- instance_initiated_shutdown_behavior:String(255)
   =>
  instance_initiated_shutdown_terminate:Boolean()
  as suggested by Vish.
- Added Johannes Erdfelt to reviews as they written the vm_states state
  machine checker.
  I'd have liked to add David Subiros either, but he doesn't seem to be a
  registered user of the gerrit.

Change-Id: Ibeb94f65137feadad2c343913b39195e3f96a35e

nova/tests/test_compute.py

@@ -1358,6 +1358,15 @@ class ComputeAPITestCase(BaseTestCase):
             'properties': {'kernel_id': 1, 'ramdisk_id': 1},
         }
 
+    def _run_instance(self):
+        instance = self._create_fake_instance()
+        instance_uuid = instance['uuid']
+        self.compute.run_instance(self.context, instance_uuid)
+
+        instance = db.instance_get_by_uuid(self.context, instance_uuid)
+        self.assertEqual(instance['task_state'], None)
+        return instance, instance_uuid
+
     def test_create_with_too_little_ram(self):
         """Test an instance type with too little memory"""
 
@@ -1554,13 +1563,45 @@ class ComputeAPITestCase(BaseTestCase):
 
         db.instance_destroy(self.context, instance['id'])
 
-    def test_delete(self):
+    def test_start_shutdown(self):
+        def check_state(instance_uuid, power_state_, vm_state_, task_state_):
+            instance = db.instance_get_by_uuid(self.context, instance_uuid)
+            self.assertEqual(instance['power_state'], power_state_)
+            self.assertEqual(instance['vm_state'], vm_state_)
+            self.assertEqual(instance['task_state'], task_state_)
+
+        def start_check_state(instance_uuid,
+                              power_state_, vm_state_, task_state_):
+            instance = db.instance_get_by_uuid(self.context, instance_uuid)
+            self.compute_api.start(self.context, instance)
+            check_state(instance_uuid, power_state_, vm_state_, task_state_)
+
         instance = self._create_fake_instance()
         instance_uuid = instance['uuid']
         self.compute.run_instance(self.context, instance_uuid)
 
-        instance = db.instance_get_by_uuid(self.context, instance_uuid)
+        check_state(instance_uuid, power_state.RUNNING, vm_states.ACTIVE, None)
-        self.assertEqual(instance['task_state'], None)
+
+        # NOTE(yamahata): emulate compute.manager._sync_power_state() that
+        # the instance is shutdown by itself
+        db.instance_update(self.context, instance_uuid,
+                           {'power_state': power_state.NOSTATE,
+                            'vm_state': vm_states.SHUTOFF})
+        check_state(instance_uuid, power_state.NOSTATE, vm_states.SHUTOFF,
+                    None)
+
+        start_check_state(instance_uuid,
+                          power_state.NOSTATE, vm_states.SHUTOFF, None)
+
+        db.instance_update(self.context, instance_uuid,
+                           {'shutdown_terminate': False})
+        start_check_state(instance_uuid, power_state.NOSTATE,
+                          vm_states.STOPPED, task_states.STARTING)
+
+        db.instance_destroy(self.context, instance['id'])
+
+    def test_delete(self):
+        instance, instance_uuid = self._run_instance()
 
         self.compute_api.delete(self.context, instance)
 
@@ -1569,14 +1610,21 @@ class ComputeAPITestCase(BaseTestCase):
 
         db.instance_destroy(self.context, instance['id'])
 
-    def test_delete_soft(self):
+    def test_delete_fail(self):
-        instance = self._create_fake_instance()
+        instance, instance_uuid = self._run_instance()
-        instance_uuid = instance['uuid']
+
-        self.compute.run_instance(self.context, instance['uuid'])
+        instance = db.instance_update(self.context, instance_uuid,
+                                      {'disable_terminate': True})
+        self.compute_api.delete(self.context, instance)
 
         instance = db.instance_get_by_uuid(self.context, instance_uuid)
         self.assertEqual(instance['task_state'], None)
 
+        db.instance_destroy(self.context, instance['id'])
+
+    def test_delete_soft(self):
+        instance, instance_uuid = self._run_instance()
+
         self.compute_api.soft_delete(self.context, instance)
 
         instance = db.instance_get_by_uuid(self.context, instance_uuid)
@@ -1584,6 +1632,18 @@ class ComputeAPITestCase(BaseTestCase):
 
         db.instance_destroy(self.context, instance['id'])
 
+    def test_delete_soft_fail(self):
+        instance, instance_uuid = self._run_instance()
+
+        instance = db.instance_update(self.context, instance_uuid,
+                                      {'disable_terminate': True})
+        self.compute_api.soft_delete(self.context, instance)
+
+        instance = db.instance_get_by_uuid(self.context, instance_uuid)
+        self.assertEqual(instance['task_state'], None)
+
+        db.instance_destroy(self.context, instance['id'])
+
     def test_force_delete(self):
         """Ensure instance can be deleted after a soft delete"""
         instance = self._create_fake_instance()
@@ -1621,7 +1681,7 @@ class ComputeAPITestCase(BaseTestCase):
         instance = self._create_fake_instance()
         instance_uuid = instance['uuid']
         instance_id = instance['id']
-        self.compute.run_instance(self.context, instance_uuid )
+        self.compute.run_instance(self.context, instance_uuid)
         db.instance_update(self.context, instance_id,
                            {'vm_state': vm_states.SUSPENDED})
         instance = db.instance_get(self.context, instance_id)