From ff2291756e3277a56a6b526a25ddcc247f59de0d Mon Sep 17 00:00:00 2001
From: Billy Olsen <billy.olsen@canonical.com>
Date: Wed, 3 Dec 2014 16:23:51 -0700
Subject: [PATCH] Refactor loop from code review feedback. Address possibility
 of the remote value not being set prior to being used.

---
 hooks/ceilometer_contexts.py           | 27 +++++++++++++-------------
 hooks/shared-db-relation-departed      |  1 +
 unit_tests/test_ceilometer_contexts.py | 18 +++++++++++++++--
 3 files changed, 31 insertions(+), 15 deletions(-)
 create mode 120000 hooks/shared-db-relation-departed

diff --git a/hooks/ceilometer_contexts.py b/hooks/ceilometer_contexts.py
index 75030e4..793fdbb 100644
--- a/hooks/ceilometer_contexts.py
+++ b/hooks/ceilometer_contexts.py
@@ -42,28 +42,29 @@ class MongoDBContext(OSContextGenerator):
                 host = relation_get('hostname', unit, relid)
                 port = relation_get('port', unit, relid)
 
+                conf = {
+                    "db_host": host,
+                    "db_port": port,
+                    "db_name": CEILOMETER_DB
+                }
+
+                if not context_complete(conf):
+                    continue
+
                 if not use_replset:
-                    conf = {
-                        "db_host": host,
-                        "db_port": port,
-                        "db_name": CEILOMETER_DB
-                    }
+                    return conf
 
-                    if context_complete(conf):
-                        return conf
-                else:
-                    if replset is None:
-                        replset = relation_get('replset', unit, relid)
+                if replset is None:
+                    replset = relation_get('replset', unit, relid)
 
-                    mongo_servers.append('{}:{}'.format(host, port))
+                mongo_servers.append('{}:{}'.format(host, port))
 
         if mongo_servers:
-            conf = {
+            return {
                 'db_mongo_servers': ','.join(mongo_servers),
                 'db_name': CEILOMETER_DB,
                 'db_replset': replset
             }
-            return conf
 
         return {}
 
diff --git a/hooks/shared-db-relation-departed b/hooks/shared-db-relation-departed
new file mode 120000
index 0000000..c948469
--- /dev/null
+++ b/hooks/shared-db-relation-departed
@@ -0,0 +1 @@
+ceilometer_hooks.py
\ No newline at end of file
diff --git a/unit_tests/test_ceilometer_contexts.py b/unit_tests/test_ceilometer_contexts.py
index a696b74..5d63575 100644
--- a/unit_tests/test_ceilometer_contexts.py
+++ b/unit_tests/test_ceilometer_contexts.py
@@ -6,11 +6,11 @@ import ceilometer_utils as utils
 from test_utils import CharmTestCase, mock_open
 
 TO_PATCH = [
+    'config',
     'relation_get',
     'relation_ids',
     'related_units',
-    'config',
-    'os_release'
+    'os_release',
 ]
 
 
@@ -69,6 +69,20 @@ class CeilometerContextsTest(CharmTestCase):
                           {'db_host': 'mongodb-0', 'db_port': 8090,
                            'db_name': 'ceilometer'})
 
+    @patch.object(contexts, 'context_complete')
+    def test_mongodb_context_related_replset_missing_values(self, mock_ctxcmp):
+        mock_ctxcmp.return_value = False
+        self.relation_ids.return_value = ['shared-db:0']
+        self.related_units.return_value = ['mongodb/0']
+        data = {
+            'hostname': None,
+            'port': 8090,
+            'replset': 'replset-1'
+        }
+        self.test_relation.set(data)
+        self.os_release.return_value = 'icehouse'
+        self.assertEquals(contexts.MongoDBContext()(), {})
+
     def test_mongodb_context_related_replset_multiple_mongo(self):
         self.relation_ids.return_value = ['shared-db:0']
         related_units = {