Allow local dynamodb to be installed on another host than localhost

celery/backends/dynamodb.py

@@ -1,5 +1,6 @@
 """AWS DynamoDB result store backend."""
 from collections import namedtuple
+from ipaddress import ip_address
 from time import sleep, time
 from typing import Any, Dict
 
@@ -96,9 +97,9 @@ def __init__(self, url=None, table_name=None, *args, **kwargs):
 
             aws_credentials_given = access_key_given
 
-            if region == 'localhost':
+            if region == 'localhost' or DynamoDBBackend._is_valid_ip(region):
                 # We are using the downloadable, local version of DynamoDB
-                self.endpoint_url = f'http://localhost:{port}'
+                self.endpoint_url = f'http://{region}:{port}'
                 self.aws_region = 'us-east-1'
                 logger.warning(
                     'Using local-only DynamoDB endpoint URL: {}'.format(
@@ -153,6 +154,14 @@ def __init__(self, url=None, table_name=None, *args, **kwargs):
                 secret_access_key=aws_secret_access_key
             )
 
+    @staticmethod
+    def _is_valid_ip(ip):
+        try:
+            ip_address(ip)
+            return True
+        except ValueError:
+            return False
+
     def _get_client(self, access_key_id=None, secret_access_key=None):
         """Get client connection."""
         if self._client is None:

t/unit/backends/test_dynamodb.py

@@ -63,23 +63,26 @@ def test_get_client_explicit_endpoint(self):
             )
             assert backend.endpoint_url == 'http://my.domain.com:666'
 
-    def test_get_client_local(self):
+    @pytest.mark.parametrize("dynamodb_host", [
+        'localhost', '127.0.0.1',
+    ])
+    def test_get_client_local(self, dynamodb_host):
         table_creation_path = \
             'celery.backends.dynamodb.DynamoDBBackend._get_or_create_table'
         with patch('boto3.client') as mock_boto_client, \
                 patch(table_creation_path):
             backend = DynamoDBBackend(
                 app=self.app,
-                url='dynamodb://@localhost:8000'
+                url=f'dynamodb://@{dynamodb_host}:8000'
             )
             client = backend._get_client()
             assert backend.client is client
             mock_boto_client.assert_called_once_with(
                 'dynamodb',
-                endpoint_url='http://localhost:8000',
+                endpoint_url=f'http://{dynamodb_host}:8000',
                 region_name='us-east-1'
             )
-            assert backend.endpoint_url == 'http://localhost:8000'
+            assert backend.endpoint_url == f'http://{dynamodb_host}:8000'
 
     def test_get_client_credentials(self):
         table_creation_path = \