[batch] Use _batch_client() to query supported_regions() and default_region()

hail/python/hailtop/batch/backend.py

@@ -24,7 +24,6 @@
 from hailtop.aiotools.validators import validate_file
 from hailtop.batch.hail_genetics_images import HAIL_GENETICS_IMAGES, hailgenetics_hail_image_for_current_python_version
 from hailtop.batch_client.aioclient import BatchClient as AioBatchClient
-from hailtop.batch_client.client import BatchClient
 from hailtop.batch_client.parse import parse_cpu_in_mcpu
 from hailtop.config import ConfigVariable, configuration_of, get_deploy_config, get_remote_tmpdir
 from hailtop.utils import async_to_blocking, bounded_gather, parse_docker_image_reference, url_scheme
@@ -527,39 +526,35 @@ class ServiceBackend(Backend[bc.Batch]):
     ANY_REGION: ClassVar[List[str]] = ['any_region']
     """A special value that indicates a job may run in any region."""
 
-    @staticmethod
-    def supported_regions():
+    def supported_regions(self):
         """
         Get the supported cloud regions
 
         Examples
         --------
-        >>> regions = ServiceBackend.supported_regions()
+        >>> regions = service_backend.supported_regions()  # doctest: +SKIP
 
         Returns
         -------
         A list of the supported cloud regions
         """
-        with BatchClient('dummy') as dummy_client:
-            return dummy_client.supported_regions()
+        return async_to_blocking(self._batch_client_sync().supported_regions())
 
-    @staticmethod
-    def default_region():
+    def default_region(self):
         """
         Get the default cloud region
 
         This value is "us-central1" for the Hail Team maintained Batch instance.
 
         Examples
         --------
-        >>> region = ServiceBackend.default_region()
+        >>> region = service_backend.default_region()  # doctest: +SKIP
 
         Returns
         -------
         The default region jobs run in when no regions are specified
         """
-        with BatchClient('dummy') as dummy_client:
-            return dummy_client.default_region()
+        return async_to_blocking(self._batch_client_sync().default_region())
 
     def __init__(
         self,
@@ -573,6 +568,9 @@ def __init__(
         gcs_requester_pays_configuration: Optional[GCSRequesterPaysConfiguration] = None,
         gcs_bucket_allow_list: Optional[List[str]] = None,
     ):
+        self.__batch_client: Optional[AioBatchClient] = None
+        self._token = token
+
         if len(args) > 2:
             raise TypeError(f'ServiceBackend() takes 2 positional arguments but {len(args)} were given')
         if len(args) >= 1:
@@ -598,7 +596,6 @@ def __init__(
                 'MY_BILLING_PROJECT`'
             )
         self._billing_project = billing_project
-        self._token = token
 
         self.remote_tmpdir = get_remote_tmpdir('ServiceBackend', bucket=bucket, remote_tmpdir=remote_tmpdir)
 
@@ -634,18 +631,20 @@ def __init__(
                 assert isinstance(regions_from_conf, str)
                 regions = regions_from_conf.split(',')
             else:
-                regions = [ServiceBackend.default_region()]
+                regions = [self.default_region()]
         elif regions == ServiceBackend.ANY_REGION:
             regions = None
 
         self.regions = regions
-        self.__batch_client: Optional[AioBatchClient] = None
 
     async def _batch_client(self) -> AioBatchClient:
         if self.__batch_client is None:
             self.__batch_client = await AioBatchClient.create(self._billing_project, _token=self._token)
         return self.__batch_client
 
+    def _batch_client_sync(self) -> AioBatchClient:
+        return async_to_blocking(self._batch_client())
+
     @property
     def _fs(self) -> RouterAsyncFS:
         return self.__fs