From a1e075bef82abf1dbfdf734b533c17c978529f2f Mon Sep 17 00:00:00 2001
From: Yashvardhan Nanavati <yashn@bu.edu>
Date: Aug 09 2019 20:16:49 +0000
Subject: Respond with a nicer error when the gating.yaml source is down


If you turn on the RemoteRule, greenwave will retrieve the `gating.yaml` from another source, which could be down or returning 500 for X or Y reasons.

In this situation, greenwave returns a 500 error without any explanations.

This change would have greenwave handle this situation a bit better and return with an error code some error message as to why it cannot proceed as expected.

---

diff --git a/greenwave/resources.py b/greenwave/resources.py
index 038af19..9f1ddfd 100644
--- a/greenwave/resources.py
+++ b/greenwave/resources.py
@@ -12,6 +12,7 @@ import json
 from io import BytesIO
 import tarfile
 import subprocess
+import socket
 
 from urllib.parse import urlparse
 import xmlrpc.client
@@ -129,8 +130,11 @@ class WaiversRetriever(BaseRetriever):
 def retrieve_scm_from_koji(nvr):
     """ Retrieve cached rev and namespace from koji using the nvr """
     koji_url = current_app.config['KOJI_BASE_URL']
-    proxy = xmlrpc.client.ServerProxy(koji_url)
-    build = proxy.getBuild(nvr)
+    try:
+        proxy = xmlrpc.client.ServerProxy(koji_url)
+        build = proxy.getBuild(nvr)
+    except (xmlrpc.client.ProtocolError, socket.error)  as err:
+        raise ConnectionError('Could not reach Koji: {}'.format(err))
     return retrieve_scm_from_koji_build(nvr, build, koji_url)
 
 
diff --git a/greenwave/tests/test_retrieve_gating_yaml.py b/greenwave/tests/test_retrieve_gating_yaml.py
index d2c5c17..0705957 100644
--- a/greenwave/tests/test_retrieve_gating_yaml.py
+++ b/greenwave/tests/test_retrieve_gating_yaml.py
@@ -2,6 +2,7 @@
 
 import subprocess
 import io
+import socket
 
 import pytest
 import mock
@@ -9,7 +10,7 @@ from werkzeug.exceptions import BadGateway
 
 import greenwave.app_factory
 from greenwave.resources import (
-    retrieve_scm_from_koji_build, retrieve_yaml_remote_rule)
+    retrieve_scm_from_koji_build, retrieve_yaml_remote_rule, retrieve_scm_from_koji)
 
 KOJI_URL = 'https://koji.fedoraproject.org/kojihub'
 
@@ -155,3 +156,15 @@ def test_retrieve_yaml_remote_rule_git_archive_error(mock_subp):
     with pytest.raises(BadGateway, match=expected_error):
         with app.app_context():
             retrieve_yaml_remote_rule('85e796daaa', 'python-requests', 'rpms')
+
+
+@mock.patch('greenwave.resources.xmlrpc.client.ServerProxy')
+def test_retrieve_scm_from_koji_build_socket_error(mock_xmlrpc_client):
+    mock_auth_server = mock_xmlrpc_client.return_value
+    mock_auth_server.getBuild.side_effect = socket.error('Socket is closed')
+    app = greenwave.app_factory.create_app()
+    nvr = 'nethack-3.6.1-3.fc29'
+    expected_error = 'Could not reach Koji: Socket is closed'
+    with pytest.raises(socket.error, match=expected_error):
+        with app.app_context():
+            retrieve_scm_from_koji(nvr)
diff --git a/greenwave/tests/test_utils.py b/greenwave/tests/test_utils.py
index c3abd12..adac2a8 100644
--- a/greenwave/tests/test_utils.py
+++ b/greenwave/tests/test_utils.py
@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: GPL-2.0+
 
 import pytest
+import urllib3
 
 import json
 
@@ -17,7 +18,8 @@ from greenwave.utils import json_error
     (ConnectionError('ERROR'), 502, 'ERROR'),
     (ConnectTimeout('TIMEOUT'), 502, 'TIMEOUT'),
     (Timeout('TIMEOUT'), 504, 'TIMEOUT'),
-    (InternalServerError(), 500, 'The server encountered an internal error')
+    (InternalServerError(), 500, 'The server encountered an internal error'),
+    (urllib3.exceptions.MaxRetryError('MAX_RETRY', '.../gating.yaml'), 502, 'There was an error retrieving the gating.yaml file at .../gating.yaml')
 ])
 def test_json_connection_error(error, expected_status_code,
                                expected_error_message_part):
diff --git a/greenwave/utils.py b/greenwave/utils.py
index 1166144..a2717a6 100644
--- a/greenwave/utils.py
+++ b/greenwave/utils.py
@@ -5,6 +5,7 @@ import logging
 import os
 import hashlib
 import datetime
+import urllib3
 
 from flask import jsonify, current_app, request
 from flask.config import Config
@@ -34,6 +35,13 @@ def json_error(error):
         current_app.logger.exception('Timeout error: {}'.format(error))
         msg = 'Timeout connecting to upstream server: {}'.format(error)
         status_code = 504
+    elif isinstance(error, urllib3.exceptions.MaxRetryError):
+        current_app.logger.exception('Connection error: {}'.format(error))
+        if error.url.endswith('gating.yaml'):
+            msg = 'There was an error retrieving the gating.yaml file at {}'.format(error.url)
+        else:
+            msg = 'Error connecting to {}'.format(error.url)
+        status_code = 502
     else:
         current_app.logger.exception('Unexpected server error: {}'.format(error))
         msg = 'Server encountered unexpected error'