Address review feedback.

1) Use the new cert location as the fallback path.

2) Log a warning when no certs are present in the cert location,
   checking in system being migrated, and after the bind mount of
   that path into the ISO runtime environment.

suse_migration_services/units/prepare.py

@@ -15,6 +15,7 @@
 # You should have received a copy of the GNU General Public License
 # along with suse-migration-services. If not, see <http://www.gnu.org/licenses/>
 #
+import glob
 import logging
 import os
 import shutil
@@ -67,7 +68,7 @@ def main():
         '/etc/pki/trust/anchors/'
     ]
     cache_cloudregister_path = '/var/cache/cloudregister'
-    cloud_register_certs_path_fallback = '/var/lib/regionService/certs'
+    cloud_register_certs_path_fallback = '/usr/lib/regionService/certs'
 
     cloud_register_metadata = ""
 
@@ -87,6 +88,9 @@ def main():
             suse_cloud_regionsrv_setup,
             cloud_register_certs_path_fallback
         )
+        warn_if_regionsrv_certs_not_found(
+            root_path + cloud_register_certs_path, log
+        )
     if os.path.exists(hosts_setup):
         shutil.copy(
             hosts_setup, '/etc/hosts'
@@ -214,6 +218,9 @@ def main():
                     cloud_register_certs_path
                 ]
             )
+            warn_if_regionsrv_certs_not_found(
+                cloud_register_certs_path, log
+            )
             update_smt_cache = '/usr/sbin/updatesmtcache'
             if os.path.isfile(update_smt_cache):
                 log.info('Updating SMT cache')
@@ -261,6 +268,16 @@ def get_regionsrv_certs_path(suse_cloud_regionsrv_setup, fallback):
     return regionsrv_setup.get('server', 'certlocation', fallback=fallback)
 
 
+def warn_if_regionsrv_certs_not_found(certs_path, log):
+    """
+    Log a warning if no PEM files are found at the specified certs path
+    in the system being migrated.
+    """
+    if not glob.glob(os.path.join(certs_path, '*.pem')):
+        log.warning("No certs found under specified certs path: %s",
+                    repr(certs_path))
+
+
 def update_regionsrv_setup(root_path, suse_cloud_regionsrv_setup):
     """
     Note: This method is specific to the SUSE Public Cloud Infrastructure

test/unit/units/prepare_test.py

@@ -1,5 +1,9 @@
+import os
 import shutil
-from tempfile import NamedTemporaryFile
+from tempfile import (
+    NamedTemporaryFile,
+    mkdtemp
+)
 from configparser import ConfigParser
 from unittest.mock import (
     patch, call, Mock, MagicMock, mock_open
@@ -9,7 +13,7 @@
 
 from suse_migration_services.units.prepare import (
     main, update_regionsrv_setup, get_regionsrv_client_file_location,
-    get_regionsrv_certs_path
+    get_regionsrv_certs_path, warn_if_regionsrv_certs_not_found
 )
 
 from suse_migration_services.suse_connect import SUSEConnect
@@ -457,3 +461,30 @@ def test_get_regionsrv_certs_path_certlocation(
             tmp_regionserverclnt.name,
             'foo'
         ) == '/var/lib/regionService/certs'
+
+    def test_warn_if_regionsrv_certs_not_found(
+        self,
+        mock_Command_run,
+        mock_Fstab,
+        mock_logger_setup,
+        mock_update_regionsrv_setup
+    ):
+        tmp_certs_dir = mkdtemp()
+
+        log = Mock(spec=['warning'])
+
+        # verify that log.warning() is called when dir has no pem files
+        warn_if_regionsrv_certs_not_found(tmp_certs_dir, log)
+        assert len(log.warning.call_args_list) == 1
+
+        # reset the log mock object
+        log.reset_mock()
+
+        # verify that log.warning() is not called when dir has pem files
+        tmp_pem_path = os.path.join(tmp_certs_dir, 'dummy_cert.pem')
+        open(tmp_pem_path, 'w').close()
+        warn_if_regionsrv_certs_not_found(tmp_certs_dir, log)
+        assert len(log.warning.call_args_list) == 0
+
+        # cleanup tmp_certs_dir
+        shutil.rmtree(tmp_certs_dir, ignore_errors=True)