Add timeout to requests.get() in kolla/cmd/build.py

When kolla-build is running, if there are network issues or if the
source's location (like http://tarballs.openstack.org) fails to
respond due to high number of concurrent requests, kolla-build just
hangs/blocks indefinitely.

This patch set resolves this issue by adding a timeout of 120
seconds for requests.get() in kolla/cmd/build.py, adds a unit test
for it in kolla/tests/test_build.py and also the "timeout" argument
in kolla/common/config.py.

Change-Id: I7c8745a20b9bd1c3f5d6a55c72a794f16fd7e513
Closes-Bug: #1548614

kolla/cmd/build.py

@@ -164,7 +164,14 @@ class WorkerThread(threading.Thread):
         if source.get('type') == 'url':
             LOG.debug("%s:Getting archive from %s", image['name'],
                       source['source'])
-            r = requests.get(source['source'])
+            try:
+                r = requests.get(source['source'], timeout=self.conf.timeout)
+            except requests_exc.Timeout:
+                LOG.exception('Request timed out while getting archive'
+                              ' from %s', source['source'])
+                image['status'] = "error"
+                image['logs'] = str()
+                return
 
             if r.status_code == 200:
                 with open(dest_archive, 'wb') as f:

kolla/common/config.py

@@ -131,6 +131,8 @@ _CLI_OPTS = [
     cfg.BoolOpt('template-only', default=False,
                 deprecated_group='kolla-build',
                 help=("Don't build images. Generate Dockerfile only")),
+    cfg.IntOpt('timeout', default=120,
+               help='Time in seconds after which any operation times out'),
 ]
 
 _BASE_OPTS = [

kolla/tests/test_build.py

@@ -14,6 +14,7 @@ import fixtures
 import itertools
 import mock
 import os
+import requests
 
 from kolla.cmd import build
 from kolla.tests import base
@@ -106,6 +107,27 @@ class WorkerThreadTest(base.TestCase):
             nocache=False, rm=True, pull=True, forcerm=True,
             buildargs=build_args)
 
+    @mock.patch('docker.Client')
+    @mock.patch('requests.get')
+    def test_requests_get_timeout(self, mock_get, mock_client):
+        worker = build.WorkerThread(mock.Mock(),
+                                    mock.Mock(),
+                                    self.conf)
+        self.image['source'] = {
+            'source': 'http://fake/source',
+            'type': 'url',
+            'name': 'fake-image-base'
+        }
+        mock_get.side_effect = requests.exceptions.Timeout
+        get_result = worker.process_source(self.image,
+                                           self.image['source'])
+
+        self.assertIsNone(get_result)
+        self.assertEqual(self.image['status'], 'error')
+        self.assertEqual(self.image['logs'], str())
+        mock_get.assert_called_once_with(self.image['source']['source'],
+                                         timeout=120)
+
 
 class KollaWorkerTest(base.TestCase):