Automatic table creation and capacity parameters.

src/flask_session/__init__.py

@@ -114,6 +114,12 @@ def _get_interface(self, app):
         SESSION_DYNAMODB_URL = config.get(
             "SESSION_DYNAMODB_URL", Defaults.SESSION_DYNAMODB_URL
         )
+        SESSION_DYNAMODB_READ = config.get(
+            "SESSION_DYNAMODB_READ", Defaults.SESSION_DYNAMODB_READ
+        )
+        SESSION_DYNAMODB_WRITE = config.get(
+            "SESSION_DYNAMODB_WRITE", Defaults.SESSION_DYNAMODB_WRITE
+        )
 
         common_params = {
             "key_prefix": SESSION_KEY_PREFIX,
@@ -182,6 +188,8 @@ def _get_interface(self, app):
                 client=SESSION_DYNAMODB,
                 table_name=SESSION_DYNAMODB_TABLE,
                 url=SESSION_DYNAMODB_URL,
+                read_capacity=SESSION_DYNAMODB_READ,
+                write_capacity=SESSION_DYNAMODB_WRITE,
             )
 
         else:

src/flask_session/defaults.py

@@ -44,3 +44,5 @@ class Defaults:
     SESSION_DYNAMODB = None
     SESSION_DYNAMODB_TABLE = "FlaskSession"
     SESSION_DYNAMODB_URL = "http://localhost:8000"
+    SESSION_DYNAMODB_READ = 5
+    SESSION_DYNAMODB_WRITE = 5

src/flask_session/dynamodb/dynamodb.py

@@ -33,6 +33,8 @@ class DynamoDBSessionInterface(ServerSideSessionInterface):
     :param sid_length: The length of the generated session id in bytes.
     :param table_name: DynamoDB table name to store the session.
     :param url: DynamoDB URL for local testing.
+    :param read_capacity: DynamoDB table read capacity units.
+    :param write_capacity: DynamoDB table write capacity units.
 
     .. versionadded:: 0.6
         The `sid_length` parameter was added.
@@ -54,23 +56,41 @@ def __init__(
         serialization_format: str = Defaults.SESSION_SERIALIZATION_FORMAT,
         table_name: str = Defaults.SESSION_DYNAMODB_TABLE,
         url: str = Defaults.SESSION_DYNAMODB_URL,
+        read_capacity: int = Defaults.SESSION_DYNAMODB_READ,
+        write_capacity: int = Defaults.SESSION_DYNAMODB_WRITE,
     ):
+
         if client is None:
             warnings.warn(
                 "No valid DynamoDBServiceResource instance provided, attempting to create a new instance on localhost:8000.",
                 RuntimeWarning,
                 stacklevel=1,
             )
             client = boto3.resource("dynamodb", endpoint_url=url)
+
         try:
+            client.create_table(
+                AttributeDefinitions=[
+                    {"AttributeName": "id", "AttributeType": "S"},
+                ],
+                TableName=table_name,
+                KeySchema=[
+                    {"AttributeName": "id", "KeyType": "HASH"},
+                ],
+                ProvisionedThroughput={
+                    "ReadCapacityUnits": read_capacity,
+                    "WriteCapacityUnits": write_capacity,
+                },
+            )
+
             client.meta.client.update_time_to_live(
                 TableName=self.table_name,
                 TimeToLiveSpecification={
                     "Enabled": True,
                     "AttributeName": "expiration",
                 },
             )
-        except AttributeError:
+        except (AttributeError, client.meta.client.exceptions.ResourceInUseException):
             pass
 
         self.client = client

tests/test_dynamodb.py

@@ -18,8 +18,8 @@ def setup_dynamodb(self):
         self.client = boto3.resource(
             "dynamodb", endpoint_url=Defaults.SESSION_DYNAMODB_URL
         )
-        self.store = self.client.Table(Defaults.SESSION_DYNAMODB_TABLE)
         try:
+            self.store = self.client.Table(Defaults.SESSION_DYNAMODB_TABLE)
             scan = self.store.scan()
             with self.store.batch_writer() as batch:
                 for each in scan.get("Items"):
@@ -28,17 +28,17 @@ def setup_dynamodb(self):
                             "id": each.get("id"),
                         }
                     )
-            yield
-        finally:
-            scan = self.store.scan()
-            with self.store.batch_writer() as batch:
-                for each in scan.get("Items"):
-                    batch.delete_item(
-                        Key={
-                            "id": each.get("id"),
-                        }
-                    )
+        except self.client.meta.client.exceptions.ResourceNotFoundException:
             pass
+        yield
+        scan = self.store.scan()
+        with self.store.batch_writer() as batch:
+            for each in scan.get("Items"):
+                batch.delete_item(
+                    Key={
+                        "id": each.get("id"),
+                    }
+                )
 
     def test_dynamodb_default(self, app_utils):
         with self.setup_dynamodb():