Inspector: better error message on DiscoveryFailure

The keystoneauth's error message on connection problems is very
confusing:

    Version requested but version discovery document was not found and
    allow_version_hack was False

While I'm trying to improve the situation in [1], it still won't be
perfect. This patch adds some context to DiscoveryFailure.

We should probably do the same for other services, but inspector is
particularly affected since it can be used standalone.

[1] https://review.opendev.org/c/openstack/keystoneauth/+/825540

Change-Id: Ibd41580d1389c7584639bf000e330fec5ee1b73d

2 files changed, 21 insertions, 3 deletions

diff --git a/ironic/drivers/modules/inspector.py b/ironic/drivers/modules/inspector.py
index ba29e0f14..833934793 100644
--- a/ironic/drivers/modules/inspector.py
+++ b/ironic/drivers/modules/inspector.py
@@ -20,6 +20,7 @@ import shlex
 from urllib import parse as urlparse
 
 import eventlet
+from keystoneauth1 import exceptions as ks_exception
 import openstack
 from oslo_log import log as logging
 
@@ -66,9 +67,14 @@ def _get_client(context):
     conf['ironic-inspector'] = conf.pop('inspector')
     # TODO(pas-ha) investigate possibility of passing user context here,
     # similar to what neutron/glance-related code does
-    return openstack.connection.Connection(
-        session=session,
-        oslo_conf=conf).baremetal_introspection
+    try:
+        return openstack.connection.Connection(
+            session=session,
+            oslo_conf=conf).baremetal_introspection
+    except ks_exception.DiscoveryFailure as exc:
+        raise exception.ConfigInvalid(
+            _("Could not contact ironic-inspector for version discovery: %s")
+            % exc)
 
 
 def _get_callback_endpoint(client):
diff --git a/ironic/tests/unit/drivers/modules/test_inspector.py b/ironic/tests/unit/drivers/modules/test_inspector.py
index 3356ce813..09d70eba9 100644
--- a/ironic/tests/unit/drivers/modules/test_inspector.py
+++ b/ironic/tests/unit/drivers/modules/test_inspector.py
@@ -13,6 +13,7 @@
 from unittest import mock
 
 import eventlet
+from keystoneauth1 import exceptions as ks_exception
 import openstack
 
 from ironic.common import context
@@ -61,6 +62,17 @@ class GetClientTestCase(db_base.DbTestCase):
         self.assertEqual(1, mock_auth.call_count)
         self.assertEqual(1, mock_session.call_count)
 
+    def test__get_client_connection_problem(
+            self, mock_conn, mock_session, mock_auth):
+        mock_conn.side_effect = ks_exception.DiscoveryFailure("")
+        self.assertRaises(exception.ConfigInvalid,
+                          inspector._get_client, self.context)
+        mock_conn.assert_called_once_with(
+            session=mock.sentinel.session,
+            oslo_conf=mock.ANY)
+        self.assertEqual(1, mock_auth.call_count)
+        self.assertEqual(1, mock_session.call_count)
+
 
 class BaseTestCase(db_base.DbTestCase):
     def setUp(self):