Adding back "wrapped" exceptions in Refresh/Transport errors.

Author: dhermes

google/auth/_default.py

@@ -71,7 +71,8 @@ def _load_credentials_from_file(filename):
             info = json.load(file_obj)
         except ValueError as caught_exc:
             new_exc = exceptions.DefaultCredentialsError(
-                'File {} is not a valid json file.'.format(filename))
+                'File {} is not a valid json file.'.format(filename),
+                caught_exc)
             six.raise_from(new_exc, caught_exc)
 
     # The type key should indicate that the file is either a service account
@@ -84,9 +85,9 @@ def _load_credentials_from_file(filename):
         try:
             credentials = _cloud_sdk.load_authorized_user_credentials(info)
         except ValueError as caught_exc:
-            new_exc = exceptions.DefaultCredentialsError(
-                'Failed to load authorized user credentials from {}'.format(
-                    filename))
+            msg = 'Failed to load authorized user credentials from {}'.format(
+                filename)
+            new_exc = exceptions.DefaultCredentialsError(msg, caught_exc)
             six.raise_from(new_exc, caught_exc)
         # Authorized user credentials do not contain the project ID.
         return credentials, None
@@ -98,9 +99,9 @@ def _load_credentials_from_file(filename):
             credentials = (
                 service_account.Credentials.from_service_account_info(info))
         except ValueError as caught_exc:
-            new_exc = exceptions.DefaultCredentialsError(
-                'Failed to load service account credentials from {}'.format(
-                    filename))
+            msg = 'Failed to load service account credentials from {}'.format(
+                filename)
+            new_exc = exceptions.DefaultCredentialsError(msg, caught_exc)
             six.raise_from(new_exc, caught_exc)
         return credentials, info.get('project_id')
 

google/auth/compute_engine/credentials.py

@@ -92,7 +92,7 @@ def refresh(self, request):
                 request,
                 service_account=self._service_account_email)
         except exceptions.TransportError as caught_exc:
-            new_exc = exceptions.RefreshError()
+            new_exc = exceptions.RefreshError(caught_exc)
             six.raise_from(new_exc, caught_exc)
 
     @property

google/auth/transport/_http_client.py

@@ -106,7 +106,7 @@ def __call__(self, url, method='GET', body=None, headers=None,
             return Response(response)
 
         except (http_client.HTTPException, socket.error) as caught_exc:
-            new_exc = exceptions.TransportError()
+            new_exc = exceptions.TransportError(caught_exc)
             six.raise_from(new_exc, caught_exc)
 
         finally:

google/auth/transport/requests.py

@@ -118,7 +118,7 @@ def __call__(self, url, method='GET', body=None, headers=None,
                 **kwargs)
             return _Response(response)
         except requests.exceptions.RequestException as caught_exc:
-            new_exc = exceptions.TransportError()
+            new_exc = exceptions.TransportError(caught_exc)
             six.raise_from(new_exc, caught_exc)
 
 

google/auth/transport/urllib3.py

@@ -133,7 +133,7 @@ def __call__(self, url, method='GET', body=None, headers=None,
                 method, url, body=body, headers=headers, **kwargs)
             return _Response(response)
         except urllib3.exceptions.HTTPError as caught_exc:
-            new_exc = exceptions.TransportError()
+            new_exc = exceptions.TransportError(caught_exc)
             six.raise_from(new_exc, caught_exc)
 
 

tests/compute_engine/test_credentials.py

@@ -75,9 +75,11 @@ def test_refresh_success(self, get, utcnow):
     def test_refresh_error(self, get):
         get.side_effect = exceptions.TransportError('http error')
 
-        with pytest.raises(exceptions.RefreshError):
+        with pytest.raises(exceptions.RefreshError) as excinfo:
             self.credentials.refresh(None)
 
+        assert excinfo.match(r'http error')
+
     @mock.patch('google.auth.compute_engine._metadata.get', autospec=True)
     def test_before_request_refreshes(self, get):
         get.side_effect = [{

tests/test__default.py

@@ -85,6 +85,7 @@ def test__load_credentials_from_file_authorized_user_bad_format(tmpdir):
         _default._load_credentials_from_file(str(filename))
 
     assert excinfo.match(r'Failed to load authorized user')
+    assert excinfo.match(r'missing fields')
 
 
 def test__load_credentials_from_file_service_account():
@@ -102,6 +103,7 @@ def test__load_credentials_from_file_service_account_bad_format(tmpdir):
         _default._load_credentials_from_file(str(filename))
 
     assert excinfo.match(r'Failed to load service account')
+    assert excinfo.match(r'missing fields')
 
 
 @mock.patch.dict(os.environ, {}, clear=True)