Gracefully handling an IRC lookup service outage

highfive/newpr.py

@@ -327,11 +327,15 @@ def get_irc_nick(gh_name):
      if the user does not exist on the rustacean database,
      or if the user has no `irc` field associated with their username
     """
-    data = urllib2.urlopen(rustaceans_api_url.format(username=gh_name))
-    if data.getcode() == 200:
-        rustacean_data = json.loads(data.read())
-        if rustacean_data:
-            return rustacean_data[0].get("irc")
+    try:
+        data = urllib2.urlopen(rustaceans_api_url.format(username=gh_name))
+        if data.getcode() == 200:
+            rustacean_data = json.loads(data.read())
+            if rustacean_data:
+                return rustacean_data[0].get("irc")
+    except urllib2.HTTPError:
+        pass
+
     return None
 
 def post_warnings(payload, config, diff, owner, repo, issue, token):

highfive/tests/test_newpr.py

@@ -255,6 +255,12 @@ def test_find_reviewer(self):
             )
 
     def setup_get_irc_nick_mocks(self, mock_urllib2, status_code, data=None):
+        if status_code != 200:
+            mock_urllib2.side_effect = HTTPError(
+                None, status_code, None, None, None
+            )
+            return
+
         mock_data = mock.Mock()
         mock_data.getcode.return_value = status_code
         mock_data.read.return_value = data
@@ -263,14 +269,12 @@ def setup_get_irc_nick_mocks(self, mock_urllib2, status_code, data=None):
 
     @mock.patch('highfive.newpr.urllib2')
     def test_get_irc_nick_non_200(self, mock_urllib2):
-        mock_data = self.setup_get_irc_nick_mocks(mock_urllib2, 300)
+        self.setup_get_irc_nick_mocks(mock_urllib2, 503)
         self.assertIsNone(newpr.get_irc_nick('foo'))
 
         mock_urllib2.urlopen.assert_called_with(
             'http://www.ncameron.org/rustaceans/user?username=foo'
         )
-        mock_data.getcode.assert_called()
-        mock_data.read.assert_not_called()
 
     @mock.patch('highfive.newpr.urllib2')
     def test_get_irc_nick_no_data(self, mock_urllib2):