horizon: don't error out for certificate issues

The code should be rewritten anyway (see
https://storyboard.openstack.org/#!/story/2002787)
and in general the detection of the dashboard location
should be more roboust, but the code should not raise
an exception.
and horizon settings are relevant only for the (few)
Horizon Tempest tests, but the system can otherwise work.

Change-Id: I62607ce4de65062a0c37bdd23220edf9ea7e6818
Story: 2003024
Task: 23048

config_tempest/services/horizon.py

@@ -13,8 +13,13 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+
+from ssl import CertificateError
+
 from six.moves import urllib
 
+from config_tempest import constants as C
+
 
 def configure_horizon(conf):
     """Derive the horizon URIs from the identity's URI."""
@@ -28,6 +33,11 @@ def configure_horizon(conf):
         urllib.request.urlopen(base)
     except urllib.error.URLError:
         has_horizon = False
+    except CertificateError as ex:
+        C.LOG.info('Certificate Error while discovering Horizon: %s', (ex))
+        has_horizon = False
+
     conf.set('service_available', 'horizon', str(has_horizon))
-    conf.set('dashboard', 'dashboard_url', base + '/')
-    conf.set('dashboard', 'login_url', base + '/auth/login/')
+    if has_horizon:
+        conf.set('dashboard', 'dashboard_url', base + '/')
+        conf.set('dashboard', 'login_url', base + '/auth/login/')

config_tempest/tests/services/test_horizon.py

@@ -13,6 +13,8 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+from ssl import CertificateError
+
 from fixtures import MonkeyPatch
 import mock
 
@@ -48,3 +50,13 @@ class TestConfigTempest(BaseConfigTempestTest):
                          "http://[::1]/dashboard/")
         self.assertEqual(self.conf.get('dashboard', 'login_url'),
                          "http://[::1]/dashboard/auth/login/")
+
+    def test_configure_horizon_certificate_error(self):
+        mock_function = mock.Mock(return_value=True)
+        mock_function.side_effect = CertificateError
+        self.useFixture(MonkeyPatch('six.moves.urllib.request.urlopen',
+                                    mock_function))
+        horizon.configure_horizon(self.conf)
+        self.assertEqual(self.conf.get('service_available', 'horizon'),
+                         "False")
+        self.assertFalse(self.conf.has_section('dashboard'))