+
+ async def is_leader_from_status(self):
+ """
+ Check to see if this unit is the leader. Returns True if so, and
+ False if it is not, or if leadership does not make sense
+ (e.g., there is no leader in this application.)
+
+ This method is a kluge that calls FullStatus in the
+ ClientFacade to get its information. Once
+ https://bugs.launchpad.net/juju/+bug/1643691 is resolved, we
+ should add a simple .is_leader property, and deprecate this
+ method.
+
+ """
+ app = self.name.split("/")[0]
+
+ c = client.ClientFacade()
+ c.connect(self.model.connection)
+
+ status = await c.FullStatus(None)
+
+ # FullStatus may be more up to date than our model, and the
+ # unit may have gone away, or we may be doing something silly,
+ # like trying to fetch leadership for a subordinate, which
+ # will not be filed where we expect in the model. In those
+ # cases, we may simply return False, as a nonexistent or
+ # subordinate unit is not a leader.
+ if not status.applications.get(app):
+ return False
+
+ if not status.applications[app].get('units'):
+ return False
+
+ if not status.applications[app]['units'].get(self.name):
+ return False
+
+ return status.applications[app]['units'][self.name].get('leader', False)
+
+
+ async def get_metrics(self):
+ metrics = await self.model.get_metrics(self.tag)
+ return metrics[self.name]