Zookeeper charm zkpeer-relation-changed issue.

[José Pekkarinen]

	Hi list,

	I'm trying to add a zkpeer-relation-changed hook to the zookeeper charm. I 
wrote some changes working in an out of date version, and I'm rewriting the 
change to be upstreamable. the new version of the change looks like:

github.com/apache/bigtop:
diff --git a/bigtop-packages/src/charm/zookeeper/layer-zookeeper/reactive/
zookeeper.py b/bigtop-packages/src/charm/zookeeper/layer-zookeeper/reactive/
zookeeper.py
index a4c7773b..51c7c75a 100644
--- a/bigtop-packages/src/charm/zookeeper/layer-zookeeper/reactive/
zookeeper.py
+++ b/bigtop-packages/src/charm/zookeeper/layer-zookeeper/reactive/
zookeeper.py
@@ -196,6 +196,12 @@ def check_cluster_departed(zkpeer, zkpeer_departed):
     check_cluster(zkpeer)
 
 
+ at when('zookeeper.started', 'leadership.is_leader', 'zkpeer.changed')
+def check_cluster_changed(zkpeer):
+    check_cluster(zkpeer)
+    zkpeer.dismiss_changed()
+
+
 @when('leadership.changed.restart_queue', 'zkpeer.joined')
 def restart_for_quorum(zkpeer):
     '''

github.com/juju-solutions/interface-zookeeper-quorum
diff --git a/peers.py b/peers.py
index 41184509..018551d2 100644
--- a/peers.py
+++ b/peers.py
@@ -30,6 +30,12 @@ class ZookeeperPeers(RelationBase):
         conv.remove_state('{relation_name}.joined')
         conv.set_state('{relation_name}.departed')
 
+
+    @hook('{peers:zookeeper-quorum}-relation-changed')
+    def changed(self):
+        conv = self.conversation()
+        conv.set_state('{relation_name}.changed')
+
     def dismiss_departed(self):
         for conv in self.conversations():
             conv.remove_state('{relation_name}.departed')
@@ -38,6 +44,10 @@ class ZookeeperPeers(RelationBase):
         for conv in self.conversations():
             conv.remove_state('{relation_name}.joined')
 
+    def dismiss_changed(self):
+        for conv in self.conversations():
+            conv.remove_state('{relation_name}.changed')
+
     def get_nodes(self):
         nodes = []
         for conv in self.conversations():

	The issue I get when executing the hook is:

# juju-run unit-zookeeper-0 hooks/zkpeer-relation-changed
Running reactive_handler_main for cuda.sh (test)
Nothing to invoke
End reactive_handler_main (test)
Traceback (most recent call last):
  File "hooks/zkpeer-relation-changed", line 19, in <module>
    main()
  File "/usr/local/lib/python3.5/dist-packages/charms/reactive/__init__.py", 
line 72, in main
    bus.dispatch(restricted=restricted_mode)
  File "/usr/local/lib/python3.5/dist-packages/charms/reactive/bus.py", line 
367, in dispatch
    _invoke(hook_handlers)
  File "/usr/local/lib/python3.5/dist-packages/charms/reactive/bus.py", line 
351, in _invoke
    handler.invoke()
  File "/usr/local/lib/python3.5/dist-packages/charms/reactive/bus.py", line 
173, in invoke
    self._action(*args)
TypeError: changed() missing 1 required positional argument: 'self'

	Which I presume it comes by the definition of check_cluster_changed, on the 
number of parameters, but I'm not that experienced with reactive charms to 
know. Can anyone shoot some thoughts on what the issue may be here?

	Thanks!

	José.