blueprint host-aggregates: host maintenance - xenapi implementation

this changeset introduces the following:

- refactoring around host-related operations for xenapi
- increased test coverage
- first cut at implementing host evacuation for a XS/XCP host

Change-Id: I8509cdde95f6777ecfa928663b0c4bedbccf5d38

2 files changed, 9 insertions, 1 deletions

diff --git a/nova/compute/api.py b/nova/compute/api.py
index be9b8dbb9..80abd37e1 100644
--- a/nova/compute/api.py
+++ b/nova/compute/api.py
@@ -1640,7 +1640,9 @@ class HostAPI(base.Base):
     def set_host_maintenance(self, context, host, mode):
         """Start/Stop host maintenance window. On start, it triggers
         guest VMs evacuation."""
-        raise NotImplementedError()
+        return _call_compute_message(self.db, "host_maintenance_mode", context,
+                                     host=host, params={"host": host,
+                                                        "mode": mode})
 
 
 class AggregateAPI(base.Base):
diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index 3066cb3a6..b64086115 100644
--- a/nova/compute/manager.py
+++ b/nova/compute/manager.py
@@ -1464,6 +1464,12 @@ class ComputeManager(manager.SchedulerDependentManager):
         return self.driver.host_power_action(host, action)
 
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
+    def host_maintenance_mode(self, context, host, mode):
+        """Start/Stop host maintenance window. On start, it triggers
+        guest VMs evacuation."""
+        return self.driver.host_maintenance_mode(host, mode)
+
+    @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     def set_host_enabled(self, context, host=None, enabled=None):
         """Sets the specified host's ability to accept new instances."""
         return self.driver.set_host_enabled(host, enabled)