Merge ~mariosplivalo/charm-mongodb:lp1420852 into ~mongodb-charmers/charm-mongodb:master

[Mario Splivalo]

Make replicaset-relation-broken not fail
Closes-Bug: LP #lp1436029

Make replicaset-relation-broken not fail

When units are being removed they are querying replicaset status
to locate the primary unit. Then, they use primary unit to remove
themselves from replicaset.

However, when the last unit is being removed (during complete
service removal) the 'primary' key in replicaseet status is no
longer there (as the unit switched to secondary, and there is no
primary).
This code change anticipates missing 'primary' key. If so, it will
cleanly exit the hook so that juju can remove the unit cleanly.

[Jay Kuri (jk0ne)]

Looks good to me.

review: Approve

diff --git a/hooks/hooks.py b/hooks/hooks.py
index eafce5a..d54919c 100755
--- a/hooks/hooks.py
+++ b/hooks/hooks.py
@@ -93,13 +93,11 @@ hooks = Hooks()
 default_mongodb_config = "/etc/mongodb.conf"
 default_mongodb_init_config = "/etc/init/mongodb.conf"
 default_mongos_list = "/etc/mongos.list"
-default_wait_for = 10
-default_max_tries = 5
+default_wait_for = 3
+default_max_tries = 7
 
 INSTALL_PACKAGES = ['mongodb-server', 'python-yaml']
 
-INIT_LOCKFILE = '/tmp/mongodb-charm.lock'
-
 # number of seconds init_replset will pause while looping to check if
 # replicaset is initialized
 INIT_CHECK_DELAY = 1.5
@@ -1166,12 +1164,6 @@ def replica_set_relation_joined():
     juju_log("replica_set_relation_joined-finish")
 
 
-def in_replica_set():
-    c = Connection('localhost')
-    r = run_admin_command(c, 'isMaster')
-    return 'setName' in r
-
-
 def am_i_primary():
     c = Connection('localhost')
     for i in xrange(10):
@@ -1266,11 +1258,6 @@ def replica_set_relation_departed():
 def replica_set_relation_broken():
     juju_log('replica_set_relation_broken-start')
 
-    if not in_replica_set():
-        juju_log('not in replica set', level=DEBUG)
-        juju_log('replica_set_relation_broken-finish')
-        return
-
     if am_i_primary():
         juju_log('I was primary - removing myself via new primary.', 'DEBUG')
         mongo_client('localhost', 'rs.stepDown()')
@@ -1278,12 +1265,16 @@ def replica_set_relation_broken():
 
     c = Connection('localhost')
     r = c.admin.command('isMaster')
-    master_node = r['primary']
-    unit = "%s:%s" % (unit_get('private-address'),
-                      config('port'))
-
-    juju_log('Removing myself via %s' % (master_node), 'DEBUG')
-    leave_replset(master_node, unit)
+    
+    try:
+        master_node = r['primary']
+    except KeyError:
+        pass
+    
+    if 'master_node' in locals():  # unit is part of replicaset, remove it!
+        unit = "%s:%s" % (unit_get('private-address'), config('port'))
+        juju_log('Removing myself via %s' % (master_node), 'DEBUG')
+        leave_replset(master_node, unit)
 
     juju_log('replica_set_relation_broken-finish')
 
diff --git a/unit_tests/test_hooks.py b/unit_tests/test_hooks.py
index aad1a96..c95e480 100644
--- a/unit_tests/test_hooks.py
+++ b/unit_tests/test_hooks.py
@@ -344,6 +344,23 @@ class MongoHooksTest(CharmTestCase):
         call1 = call('juju-local:27017', 'juju-remote:27017')
         mock_leave_replset.assert_has_calls([call1])
 
+    @patch('time.sleep')
+    @patch.object(hooks, 'Connection')
+    @patch.object(hooks, 'unit_get')
+    @patch.object(hooks, 'leave_replset')
+    @patch.object(hooks, 'am_i_primary')
+    def test_replica_set_relation_broken(self, mock_am_i_primary,
+                                         mock_leave_replset, mock_unit_get,
+                                         mock_Connection, mock_sleep):
+
+        mock_am_i_primary.return_value = False
+        hooks.replica_set_relation_broken()
+        self.assertEqual(1, mock_leave_replset.call_count)
+        mock_am_i_primary.reset_mock()
+        mock_leave_replset.reset_mock()
+        mock_am_i_primary.return_value = True
+        self.assertEqual(0, mock_leave_replset.call_count)
+
     def test_get_current_mongo_config(self):
         test_config = u"""
         # Comment