Use mock.patch to test out socket/exception paths for vulcand backend

tests/backends/test_vulcand.py

@@ -3,12 +3,12 @@
 # @Author: ahuynh
 # @Date:   2016-02-11 14:28:02
 # @Last Modified by:   ahuynh
-# @Last Modified time: 2016-02-11 15:33:08
+# @Last Modified time: 2016-02-11 17:27:07
 import unittest
 
 from sidekick import announce_services, find_matching_container, parse_args
-
 from tests import MockEtcd
+from unittest.mock import patch
 
 
 class TestVulcandBackend( unittest.TestCase ):
@@ -23,18 +23,19 @@ def setUp( self ):
         ])
 
         self.etcd_client = MockEtcd()
-
         self.container = {
             'Image': 'image:latest',
             'Ports': [{
                 'PrivatePort': 9200,
                 'IP': '0.0.0.0',
                 'Type': 'tcp',
-                'PublicPort': 9200 }, {
+                'PublicPort': 9200
+            }, {
                 'PrivatePort': 9300,
                 'IP': '0.0.0.0',
                 'Type': 'tcp',
-                'PublicPort': 9300}],
+                'PublicPort': 9300
+            }],
             'Created': 1427906382,
             'Names': ['/test'],
             'Status': 'Up 2 days'
@@ -43,4 +44,20 @@ def setUp( self ):
     def test_vulcand_announce( self ):
         """ Test `announce_services` functionality """
         services = find_matching_container( [ self.container ], self.args )
-        announce_services( services.items(), 'test', self.etcd_client, 0, 0, True )
+
+        # Successful health check
+        with patch( 'sidekick.check_health', return_value=True ):
+            announce_services( services.items(), 'test', self.etcd_client, 0, 0, True )
+            self.assertEqual( len( self.etcd_client.written.keys() ), 4 )
+
+        # Unsuccessful health check
+        self.etcd_client._reset()
+        with patch( 'sidekick.check_health', return_value=False ):
+            announce_services( services.items(), 'test', self.etcd_client, 0, 0, True )
+            self.assertEqual( len( self.etcd_client.deleted ), 4 )
+
+        # Correct etcd exception handling
+        self.etcd_client = MockEtcd( raise_exception=True )
+        with patch( 'logging.error' ) as mock_method:
+            announce_services( services.items(), 'test', self.etcd_client, 0, 0, True )
+            self.assertEquals( str(mock_method.call_args[0][0]), 'Test Exception' )