Retry API requests when a HTTP 503 "Service unavaliable" is received

Closes: #6 (closed)

Also puts in a sanity check for users missing 'orgUnitPath', at least helping to identify the issue with #8 (closed) (if not closing)

Note: failed to get any 503 while testing - probably have to let it out in the wild and wait for pipeline failures

gsuitesync/sync.py

@@ -124,6 +124,17 @@ def sync(configuration, *, read_only=True):
         LOG.info(
             'Ignoring users whose organization unit path matches %r',
             sync_config.ignore_google_org_unit_path_regex)
+        # Check that all users have an orgUnitPath
+        missing_org = [
+            u for u in all_google_users if 'orgUnitPath' not in u
+        ]
+        if len(missing_org) != 0:
+            LOG.error('User entries missing orgUnitPath: %s (starting with %s)',
+                      len(missing_org),
+                      missing_org[0]['primaryEmail'] if 'primaryEmail' in missing_org[0]
+                      else 'user with blank email')
+            raise RuntimeError('Sanity check failed: at least one user is missing orgUnitPath')
+        # Remove users matching regex
         regex = re.compile(sync_config.ignore_google_org_unit_path_regex)
         all_google_users = [
             u for u in all_google_users if not regex.match(u['orgUnitPath'])