Ignore connection errors when getting ironic ports

as a followup to I24b08612c4ffc6aca60ca08f3ff5cc769c7c041d,
this solves the case when connectivity between inspector and ironic is
broken, which can lead to the same FSM being stuck in uninitialized mode
it can't get out of w/o restart.

Change-Id: Ie238a2fca7cc5ef4961c0cb0e639ffbbe69556f7
Story: #2008971
Task: #42611

ironic_inspector/pxe_filter/dnsmasq.py

@@ -28,6 +28,7 @@ import fcntl
 import os
 import time
 
+from keystoneauth1 import exceptions as ksa_exc
 from openstack import exceptions as os_exc
 from oslo_concurrency import processutils
 from oslo_config import cfg
@@ -90,7 +91,7 @@ class DnsmasqFilter(pxe_filter.BaseFilter):
 
             # ironic_macs are all the MACs know to ironic (all ironic ports)
             ironic_macs = pxe_filter.get_ironic_macs(ironic)
-        except os_exc.SDKException:
+        except (os_exc.SDKException, ksa_exc.ConnectFailure):
             LOG.exception(
                 "Could not list ironic ports, can not sync dnsmasq PXE filter")
             return

ironic_inspector/pxe_filter/iptables.py

@@ -13,6 +13,7 @@
 
 import contextlib
 
+from keystoneauth1 import exceptions as ksa_exc
 from openstack import exceptions as os_exc
 from oslo_concurrency import processutils
 from oslo_config import cfg
@@ -118,7 +119,7 @@ class IptablesFilter(pxe_filter.BaseFilter):
             else:
                 to_deny = pxe_filter.get_inactive_macs(ironic)
                 to_allow = None
-        except os_exc.SDKException:
+        except (os_exc.SDKException, ksa_exc.ConnectFailure):
             LOG.exception(
                 "Could not list ironic ports, iptables PXE filter can not "
                 "be synced")