Merge pull request #4113 from certbot/auto-retry

Automatically retry after getting badNonce error

acme/acme/client.py

@@ -674,8 +674,25 @@ def _get_nonce(self, url):
             self._add_nonce(self.head(url))
         return self._nonces.pop()
 
-    def post(self, url, obj, content_type=JOSE_CONTENT_TYPE, **kwargs):
-        """POST object wrapped in `.JWS` and check response."""
+    def post(self, *args, **kwargs):
+        """POST object wrapped in `.JWS` and check response.
+
+        If the server responded with a badNonce error, the request will
+        be retried once.
+
+        """
+        should_retry = True
+        while True:
+            try:
+                return self._post_once(*args, **kwargs)
+            except messages.Error as error:
+                if should_retry and error.code == 'badNonce':
+                    logger.debug('Retrying request after error:\n%s', error)
+                    should_retry = False
+                else:
+                    raise
+
+    def _post_once(self, url, obj, content_type=JOSE_CONTENT_TYPE, **kwargs):
         data = self._wrap_in_jws(obj, self._get_nonce(url))
         kwargs.setdefault('headers', {'Content-Type': content_type})
         response = self._send_request('POST', url, data=data, **kwargs)

acme/acme/client_test.py

@@ -642,7 +642,9 @@ def setUp(self):
         self.wrapped_obj = mock.MagicMock()
         self.content_type = mock.sentinel.content_type
 
-        self.all_nonces = [jose.b64encode(b'Nonce'), jose.b64encode(b'Nonce2')]
+        self.all_nonces = [
+            jose.b64encode(b'Nonce'),
+            jose.b64encode(b'Nonce2'), jose.b64encode(b'Nonce3')]
         self.available_nonces = self.all_nonces[:]
 
         def send_request(*args, **kwargs):
@@ -690,7 +692,7 @@ def test_post(self):
         self.net._wrap_in_jws.assert_called_once_with(
             self.obj, jose.b64decode(self.all_nonces.pop()))
 
-        assert not self.available_nonces
+        self.available_nonces = []
         self.assertRaises(errors.MissingNonce, self.net.post,
                           'uri', self.obj, content_type=self.content_type)
         self.net._wrap_in_jws.assert_called_with(
@@ -706,6 +708,25 @@ def test_post_wrong_post_response_nonce(self):
         self.assertRaises(errors.BadNonce, self.net.post, 'uri',
                           self.obj, content_type=self.content_type)
 
+    def test_post_failed_retry(self):
+        check_response = mock.MagicMock()
+        check_response.side_effect = messages.Error.with_code('badNonce')
+
+        # pylint: disable=protected-access
+        self.net._check_response = check_response
+        self.assertRaises(messages.Error, self.net.post, 'uri',
+                          self.obj, content_type=self.content_type)
+
+    def test_post_successful_retry(self):
+        check_response = mock.MagicMock()
+        check_response.side_effect = [messages.Error.with_code('badNonce'),
+                                      self.checked_response]
+
+        # pylint: disable=protected-access
+        self.net._check_response = check_response
+        self.assertEqual(self.checked_response, self.net.post(
+            'uri', self.obj, content_type=self.content_type))
+
     def test_head_get_post_error_passthrough(self):
         self.send_request.side_effect = requests.exceptions.RequestException
         for method in self.net.head, self.net.get: