correctly removing node from cluster

hooks/cluster-relation-departed

@@ -0,0 +1 @@
+rabbitmq_server_relations.py

hooks/rabbit_utils.py

@@ -118,10 +118,12 @@ def cluster_with():
 
     # iterate over all the nodes, join to the first available
     for node in available_nodes:
-        utils.juju_log('INFO', 'Clustering with remote rabbit host (%s).' % node)
+        utils.juju_log('INFO',
+                       'Clustering with remote rabbit host (%s).' % node)
         for line in out.split('\n'):
             if re.search(node, line):
-                utils.juju_log('INFO', 'Host already clustered with %s.' % node)
+                utils.juju_log('INFO',
+                               'Host already clustered with %s.' % node)
                 return
 
             try:
@@ -142,6 +144,22 @@ def cluster_with():
     sys.exit(1)
 
 
+def break_cluster():
+    try:
+        cmd = [RABBITMQ_CTL, 'stop_app']
+        subprocess.check_call(cmd)
+        cmd = [RABBITMQ_CTL, 'reset']
+        subprocess.check_call(cmd)
+        cmd = [RABBITMQ_CTL, 'start_app']
+        subprocess.check_call(cmd)
+        utils.juju_log('INFO', 'Cluster successfully broken.')
+        return
+    except:
+        # error, no nodes available for clustering
+        utils.juju_log('ERROR', 'Error breaking rabbit cluster')
+        sys.exit(1)
+
+
 def set_node_name(name):
     # update or append RABBITMQ_NODENAME to environment config.
     # rabbitmq.conf.d is not present on all releases, so use or create

hooks/rabbitmq_server_relations.py

@@ -157,6 +157,20 @@ def cluster_changed():
     rabbit.cluster_with()
 
 
+def cluster_departed():
+    if utils.is_relation_made('ha'):
+        utils.juju_log('INFO',
+                       'hacluster relation is present, skipping native '
+                       'rabbitmq cluster config.')
+        return
+    l_unit_no = os.getenv('JUJU_UNIT_NAME').split('/')[1]
+    r_unit_no = os.getenv('JUJU_REMOTE_UNIT').split('/')[1]
+    if l_unit_no < r_unit_no:
+        utils.juju_log('INFO', 'cluster_joined: Relation lesser.')
+        return
+    rabbit.break_cluster()
+
+
 def ha_joined():
     corosync_bindiface = utils.config_get('ha-bindiface')
     corosync_mcastport = utils.config_get('ha-mcastport')
@@ -371,6 +385,7 @@ hooks = {
     'amqp-relation-changed': amqp_changed,
     'cluster-relation-joined': cluster_joined,
     'cluster-relation-changed': cluster_changed,
+    'cluster-relation-departed': cluster_departed,
     'ha-relation-joined': ha_joined,
     'ha-relation-changed': ha_changed,
     'ceph-relation-joined': ceph_joined,

revision

@@ -1 +1 @@
-111
+112