Inject instance metadata into xenstore

When using Xenserver, inject instance metadata into the xenstore, for
the use of the instance.  Implements blueprint xenstore-metadata.

Change-Id: I88a59f1b783eaaaef6ba5efd8bd448aece2f869c

3 files changed, 27 insertions, 2 deletions

diff --git a/nova/compute/api.py b/nova/compute/api.py
index eb23a2412..e5b6fb1b3 100644
--- a/nova/compute/api.py
+++ b/nova/compute/api.py
@@ -1595,6 +1595,9 @@ class API(base.Base):
     def delete_instance_metadata(self, context, instance, key):
         """Delete the given metadata item from an instance."""
         self.db.instance_metadata_delete(context, instance['uuid'], key)
+        self.compute_rpcapi.change_instance_metadata(context,
+                                                     instance=instance,
+                                                     diff={key: ['-']})
 
     @wrap_check_policy
     def update_instance_metadata(self, context, instance,
@@ -1605,15 +1608,20 @@ class API(base.Base):
         `metadata` argument will be deleted.
 
         """
+        orig = self.get_instance_metadata(context, instance)
         if delete:
             _metadata = metadata
         else:
-            _metadata = self.get_instance_metadata(context, instance)
+            _metadata = orig.copy()
             _metadata.update(metadata)
 
         self._check_metadata_properties_quota(context, _metadata)
         self.db.instance_metadata_update(context, instance['uuid'],
                                          _metadata, True)
+        diff = utils.diff_dict(orig, _metadata)
+        self.compute_rpcapi.change_instance_metadata(context,
+                                                     instance=instance,
+                                                     diff=diff)
         return _metadata
 
     def get_instance_faults(self, context, instances):
diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index ecebf2d9c..e19a4ec90 100644
--- a/nova/compute/manager.py
+++ b/nova/compute/manager.py
@@ -235,7 +235,7 @@ def _get_additional_capabilities():
 class ComputeManager(manager.SchedulerDependentManager):
     """Manages the running instances from creation to destruction."""
 
-    RPC_API_VERSION = '1.2'
+    RPC_API_VERSION = '1.3'
 
     def __init__(self, compute_driver=None, *args, **kwargs):
         """Load configuration options and connect to the hypervisor."""
@@ -1327,6 +1327,16 @@ class ComputeManager(manager.SchedulerDependentManager):
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     @checks_instance_lock
     @wrap_instance_fault
+    def change_instance_metadata(self, context, instance_uuid, diff):
+        """Update the metadata published to the instance."""
+        instance_ref = self.db.instance_get_by_uuid(context, instance_uuid)
+        LOG.debug(_("Changing instance metadata according to %(diff)r") %
+                  locals(), instance=instance_ref)
+        self.driver.change_instance_metadata(context, instance_ref, diff)
+
+    @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
+    @checks_instance_lock
+    @wrap_instance_fault
     def confirm_resize(self, context, instance_uuid, migration_id):
         """Destroys the source instance."""
         migration_ref = self.db.migration_get(context, migration_id)
diff --git a/nova/compute/rpcapi.py b/nova/compute/rpcapi.py
index 332b8153e..e637c9f64 100644
--- a/nova/compute/rpcapi.py
+++ b/nova/compute/rpcapi.py
@@ -57,6 +57,7 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
         1.0 - Initial version.
         1.1 - Adds get_host_uptime()
         1.2 - Adds check_can_live_migrate_[destination|source]
+        1.3 - Adds change_instance_metadata()
     '''
 
     BASE_RPC_API_VERSION = '1.0'
@@ -375,6 +376,12 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
                 instance_uuid=instance['uuid']),
                 topic=_compute_topic(self.topic, ctxt, None, instance))
 
+    def change_instance_metadata(self, ctxt, instance, diff):
+        self.cast(ctxt, self.make_msg('change_instance_metadata',
+                  instance_uuid=instance['uuid'], diff=diff),
+                  topic=_compute_topic(self.topic, ctxt, None, instance),
+                  version='1.3')
+
 
 class SecurityGroupAPI(nova.openstack.common.rpc.proxy.RpcProxy):
     '''Client side of the security group rpc API.