Block starting compute unless placement conf is provided

We need to signal that the compute is Ocata and since the placement is now
mandatory for Ocata, we want to hard-fail if the conf is not correct.

Depends-On: I573149b9415da2a8bb3951a4c4ce71c4c3e48c6f
Change-Id: I3919f652040f2be2641420dd469af01b268e65c9

doc/notification_samples/service-update.json

@@ -13,7 +13,7 @@
             "disabled_reason": null,
             "report_count": 1,
             "forced_down": false,
-            "version": 15
+            "version": 16
         }
     },
     "event_type": "service.update",

nova/compute/manager.py

@@ -1129,6 +1129,12 @@ class ComputeManager(manager.Manager):
             # if the configuration is wrong.
             whitelist.Whitelist(CONF.pci.passthrough_whitelist)
 
+        # NOTE(sbauza): We want the compute node to hard fail if it can't be
+        # able to provide its resources to the placement API, or it would not
+        # be able to be eligible as a destination.
+        if CONF.placement.os_region_name is None:
+            raise exception.PlacementNotConfigured()
+
         self.driver.init_host(host=self.host)
         context = nova.context.get_admin_context()
         instances = objects.InstanceList.get_by_host(

nova/exception.py

@@ -2181,3 +2181,9 @@ class Unauthorized(NovaException):
 
 class NeutronAdminCredentialConfigurationInvalid(Invalid):
     msg_fmt = _("Networking client is experiencing an unauthorized exception.")
+
+
+class PlacementNotConfigured(NovaException):
+    msg_fmt = _("This compute is not configured to talk to the placement "
+                "service. Configure the [placement] section of nova.conf "
+                "and restart the service.")

nova/objects/service.py

@@ -30,7 +30,7 @@ LOG = logging.getLogger(__name__)
 
 
 # NOTE(danms): This is the global service version counter
-SERVICE_VERSION = 15
+SERVICE_VERSION = 16
 
 
 # NOTE(danms): This is our SERVICE_VERSION history. The idea is that any
@@ -92,6 +92,9 @@ SERVICE_VERSION_HISTORY = (
     # Version 15: Indicate that nova-conductor will stop a boot if BuildRequest
     # is deleted before RPC to nova-compute.
     {'compute_rpc': '4.13'},
+    # Version 16: Indicate that nova-compute will refuse to start if it doesn't
+    # have a placement section configured.
+    {'compute_rpc': '4.13'},
 )
 
 

nova/tests/unit/compute/test_compute_mgr.py

@@ -12,6 +12,7 @@
 
 """Unit tests for ComputeManager()."""
 
+import copy
 import datetime
 import time
 
@@ -2791,6 +2792,21 @@ class ComputeManagerUnitTestCase(test.NoDBTestCase):
         self.assertRaises(exception.PciDeviceInvalidDeviceName,
                           self.compute.init_host)
 
+    def test_init_host_placement_ensures_default_config_is_unset(self):
+        # Tests that by default the placement config option is unset
+        # NOTE(sbauza): Just resets the conf opt to the real value and not
+        # the faked one.
+        fake_conf = copy.copy(CONF)
+        fake_conf.clear_default('os_region_name', group='placement')
+        self.assertIsNone(CONF.placement.os_region_name)
+
+    def test_init_host_placement_config_failure(self):
+        # Tests that we fail init_host if the placement section is
+        # configured incorrectly.
+        self.flags(os_region_name=None, group='placement')
+        self.assertRaises(exception.PlacementNotConfigured,
+                          self.compute.init_host)
+
     @mock.patch('nova.compute.manager.ComputeManager._instance_update')
     def test_error_out_instance_on_exception_not_implemented_err(self,
                                                         inst_update_mock):

nova/tests/unit/conf_fixture.py

@@ -75,6 +75,10 @@ class ConfFixture(config_fixture.Config):
                               paths.state_path_def('etc/nova/api-paste.ini'),
                               group='wsgi')
 
+        # placement group
+        self.conf.set_default('os_region_name', 'RegionOne',
+                              group='placement')
+
         config.parse_args([], default_config_files=[], configure_db=False,
                           init_rpc=False)
         policy_opts.set_defaults(self.conf)