--- cloudinit/sources/helpers/openstack.py.orig	2017-07-28 20:28:47.000000000 +0000
+++ cloudinit/sources/helpers/openstack.py	2017-12-21 08:46:06.948988192 +0000
@@ -452,21 +452,22 @@ class MetadataReader(BaseReader):
 
     def _path_read(self, path, decode=False):
 
-        def should_retry_cb(_request_args, cause):
+        def should_not_retry_cb(_request_args, cause):
             try:
                 code = int(cause.code)
-                if code >= 400:
-                    return False
+                # FIXME: Would be better to use the required field, but we don't have it here
+                if code >= 400 and not _request_args['url'][-14:] == 'meta_data.json':
+                    return True
             except (TypeError, ValueError):
                 # Older versions of requests didn't have a code.
                 pass
-            return True
+            return False
 
         response = url_helper.readurl(path,
                                       retries=self.retries,
                                       ssl_details=self.ssl_details,
                                       timeout=self.timeout,
-                                      exception_cb=should_retry_cb)
+                                      exception_cb=should_not_retry_cb)
         if decode:
             return response.contents.decode()
         else:
--- cloudinit/url_helper.py.orig	2017-07-28 20:28:47.000000000 +0000
+++ cloudinit/url_helper.py	2017-12-21 08:24:40.320084907 +0000
@@ -260,8 +260,8 @@ def readurl(url, data=None, timeout=None
                     # few seconds
                     break
             if exception_cb and exception_cb(req_args.copy(), excps[-1]):
-                # if an exception callback was given it should return None
-                # a true-ish value means to break and re-raise the exception
+                # if an exception callback was given it should return False
+                # to retry and True to interrupt and re-raise the exception
                 break
             if i + 1 < manual_tries and sec_between > 0:
                 LOG.debug("Please wait %s seconds while we wait to try again",