Email notifier returns false if self._smtp == None

When an email notifier is created and the initial smtp connection fails the
self._smtp variable is left set to None.  Now we detect that and try to
reconnect.

Change-Id: Ifbc30ee5339722357d86214b4d8c84e64dd703f7

monasca_notification/types/email_notifier.py

@@ -54,6 +54,9 @@ class EmailNotifier(AbstractNotifier):
         # Generate the message
         msg = self._create_msg(hostname, notification)
 
+        if not self._smtp and not self._smtp_connect():
+            return False
+
         try:
             self._sendmail(notification, msg)
             return True
@@ -94,8 +97,10 @@ class EmailNotifier(AbstractNotifier):
                 smtp.login(self._config['user'], self.config['password'])
 
             self._smtp = smtp
+            return True
         except Exception:
             self._log.exception("Unable to connect to email server.")
+            return False
 
     def _create_msg(self, hostname, notification):
         """Create two kind of messages:

tests/test_email_notification.py

@@ -177,6 +177,54 @@ class TestEmail(unittest.TestCase):
         self.assertIn("SMTP server disconnected. Will reconnect and retry message.", self.trap)
         self.assertIn("Unable to connect to email server.", self.trap)
 
+    @mock.patch('monasca_notification.types.email_notifier.smtplib')
+    def test_smtp_sendmail_smtp_None(self, mock_smtp):
+        """Email that fails on smtp_connect twice
+        """
+
+        metrics = []
+        metric_data = {'dimensions': {'hostname': 'foo1', 'service': 'bar1'}}
+        metrics.append(metric_data)
+        metric_data = {'dimensions': {'hostname': 'foo2', 'service': 'bar2'}}
+        metrics.append(metric_data)
+
+        mock_log = mock.MagicMock()
+        mock_log.warn = self.trap.append
+        mock_log.error = self.trap.append
+        mock_log.debug = self.trap.append
+        mock_log.info = self.trap.append
+        mock_log.exception = self.trap.append
+
+        mock_smtp.SMTP.return_value = None
+        mock_smtp.SMTP.side_effect = [socket.error,
+                                      socket.error,
+                                      socket.error]
+
+        mock_smtp.sendmail.side_effect = [smtplib.SMTPServerDisconnected,
+                                          smtplib.SMTPServerDisconnected]
+
+        # There has to be a better way to preserve exception definitions when
+        # we're mocking access to a library
+        mock_smtp.SMTPServerDisconnected = smtplib.SMTPServerDisconnected
+        mock_smtp.SMTPException = smtplib.SMTPException
+
+        email = email_notifier.EmailNotifier(mock_log)
+
+        email.config(self.email_config)
+
+        del self.trap[:]
+
+        alarm_dict = alarm(metrics)
+
+        notification = Notification('email', 0, 1, 'email notification', 'me@here.com', 0, alarm_dict)
+
+        email_result = email.send_notification(notification)
+
+        self.assertFalse(email_result)
+        self.assertIn("Connecting to Email Server {}"
+                      .format(self.email_config['server']),
+                      self.trap)
+
     @mock.patch('monasca_notification.types.email_notifier.smtplib')
     def test_smtp_sendmail_failed_connection_once_then_email(self, mock_smtp):
         """Email that fails on smtp_connect once then email