implemented DynamoDBSessionInterface and tests.

.github/workflows/test.yaml

@@ -11,6 +11,10 @@ jobs:
                 image: mongo
                 ports:
                     - 27017:27017
+            dynamodb:
+                image: amazon/dynamodb-local
+                ports:
+                    - 8000:8000
         steps:
             - uses: actions/checkout@v4
             - uses: supercharge/[email protected]

CHANGES.rst

@@ -1,10 +1,13 @@
-0.7.2 - 2024-03-21
+0.8.0
 ------------------
 
+Added
+~~~~~~~
+-   Add DynamoDB session interface (`#214 <https://github.com/pallets-eco/flask-session/pull/214>`_).
+
 Fixed
 ~~~~~
 -   Include prematurely removed ``cachelib`` dependency. Will be removed in 1.0.0 to be an optional dependency (`#223 <https://github.com/pallets-eco/flask-session/issues/223>`_).
--   Note 0.7.1 was not released due to a publishing error.
 
 
 0.7.0 - 2024-03-18

CONTRIBUTORS.md

@@ -1,5 +1,6 @@
 ## Contributors
 
+-   [necat1](https://github.com/necat1)
 -   [nebolax](https://github.com/nebolax)
 -   [Taragolis](https://github.com/Taragolis)
 -   [Lxstr](https://github.com/Lxstr)

docker-compose.yml

@@ -1,11 +1,18 @@
 version: '3.8'
 
 services:
+  dynamodb-local:
+    image: "amazon/dynamodb-local:latest"
+    container_name: dynamodb-local
+    ports:
+      - "8000:8000"
+    environment:
+      - AWS_ACCESS_KEY_ID=dummy
+      - AWS_SECRET_ACCESS_KEY=dummy
+      - AWS_DEFAULT_REGION=us-west-2
+
   mongo:
     image: mongo:latest
-    environment:
-      MONGO_INITDB_ROOT_USERNAME: root
-      MONGO_INITDB_ROOT_PASSWORD: example
     ports:
       - "27017:27017"
     volumes:
@@ -26,4 +33,5 @@ services:
 volumes:
   postgres_data:
   mongo_data:
-  redis_data:
+  redis_data:
+  dynamodb_data:

docs/api.rst

@@ -19,4 +19,5 @@ Anything documented here is part of the public API that Flask-Session provides,
 .. autoclass:: flask_session.filesystem.FileSystemSessionInterface
 .. autoclass:: flask_session.cachelib.CacheLibSessionInterface
 .. autoclass:: flask_session.mongodb.MongoDBSessionInterface
-.. autoclass:: flask_session.sqlalchemy.SqlAlchemySessionInterface
+.. autoclass:: flask_session.sqlalchemy.SqlAlchemySessionInterface
+.. autoclass:: flask_session.dynamodb.DynamoDBSessionInterface

docs/config.rst

@@ -211,6 +211,21 @@ SqlAlchemy
 
    Default: ``None``
 
+Dynamodb
+~~~~~~~~~~~~~~~~~~~~~~~
+
+.. py:data:: SESSION_DYNAMODB
+
+      A ``boto3.resource`` instance.
+
+      Default: Instance connected to ``'localhost:8000'``
+
+.. py:data:: SESSION_DYNAMODB_TABLE_NAME
+
+      The name of the table you want to use.
+
+      Default: ``'Sessions'``
+
 .. deprecated:: 0.7.0
 
    ``SESSION_FILE_DIR``, ``SESSION_FILE_THRESHOLD``, ``SESSION_FILE_MODE``. Use ``SESSION_CACHELIB`` instead.

docs/installation.rst

@@ -42,6 +42,8 @@ Flask-Session has an increasing number of directly supported storage and client
      - pymongo_
    * - SQL Alchemy
      - flask-sqlalchemy_
+   * - DynamoDB  
+     - boto3_
 
 Other libraries may work if they use the same commands as the ones listed above.
 

pyproject.toml

@@ -85,5 +85,7 @@ dev-dependencies = [
     "sphinx>=7.1.2",
     "furo>=2024.1.29",
     "sphinx-favicon>=1.0.1",
+    "boto3>=1.34.68",
+    "mypy_boto3_dynamodb>=1.34.67",
     "pymemcache>=4.0.0",
 ]

requirements/dev.txt

@@ -15,4 +15,6 @@ redis
 pymemcache
 Flask-SQLAlchemy
 pymongo
+boto3
+mypy_boto3_dynamodb
 

requirements/docs.in

@@ -7,4 +7,6 @@ redis
 cachelib
 pymongo
 flask_sqlalchemy
-pymemcache
+pymemcache
+boto3
+mypy_boto3_dynamodb

requirements/docs.txt

@@ -12,6 +12,12 @@ beautifulsoup4==4.12.3
     # via furo
 blinker==1.7.0
     # via flask
+boto3==1.34.69
+    # via -r requirements/docs.in
+botocore==1.34.69
+    # via
+    #   boto3
+    #   s3transfer
 cachelib==0.12.0
     # via -r requirements/docs.in
 certifi==2023.5.7
@@ -40,10 +46,16 @@ jinja2==3.1.2
     # via
     #   flask
     #   sphinx
+jmespath==1.0.1
+    # via
+    #   boto3
+    #   botocore
 markupsafe==2.1.2
     # via
     #   jinja2
     #   werkzeug
+mypy-boto3-dynamodb==1.34.67
+    # via -r requirements/docs.in
 packaging==23.1
     # via sphinx
 pygments==2.15.1
@@ -54,10 +66,16 @@ pymemcache==4.0.0
     # via -r requirements/docs.in
 pymongo==4.6.2
     # via -r requirements/docs.in
+python-dateutil==2.9.0.post0
+    # via botocore
 redis==5.0.1
     # via -r requirements/docs.in
 requests==2.30.0
     # via sphinx
+s3transfer==0.10.1
+    # via boto3
+six==1.16.0
+    # via python-dateutil
 snowballstemmer==2.2.0
     # via sphinx
 soupsieve==2.5
@@ -87,8 +105,12 @@ sphinxcontrib-serializinghtml==1.1.5
 sqlalchemy==2.0.27
     # via flask-sqlalchemy
 typing-extensions==4.10.0
-    # via sqlalchemy
+    # via
+    #   mypy-boto3-dynamodb
+    #   sqlalchemy
 urllib3==2.0.2
-    # via requests
+    # via
+    #   botocore
+    #   requests
 werkzeug==3.0.1
     # via flask

src/flask_session/__init__.py

@@ -104,6 +104,12 @@ def _get_interface(self, app):
             "SESSION_CLEANUP_N_REQUESTS", Defaults.SESSION_CLEANUP_N_REQUESTS
         )
 
+        # DynamoDB settings
+        SESSION_DYNAMODB = config.get("SESSION_DYNAMODB", Defaults.SESSION_DYNAMODB)
+        SESSION_DYNAMODB_TABLE = config.get(
+            "SESSION_DYNAMODB_TABLE", Defaults.SESSION_DYNAMODB_TABLE
+        )
+
         common_params = {
             "app": app,
             "key_prefix": SESSION_KEY_PREFIX,
@@ -165,6 +171,15 @@ def _get_interface(self, app):
                 bind_key=SESSION_SQLALCHEMY_BIND_KEY,
                 cleanup_n_requests=SESSION_CLEANUP_N_REQUESTS,
             )
+        elif SESSION_TYPE == "dynamodb":
+            from .dynamodb import DynamoDBSessionInterface
+
+            session_interface = DynamoDBSessionInterface(
+                **common_params,
+                client=SESSION_DYNAMODB,
+                table_name=SESSION_DYNAMODB_TABLE,
+            )
+
         else:
             raise ValueError(f"Unrecognized value for SESSION_TYPE: {SESSION_TYPE}")
 

src/flask_session/defaults.py

@@ -39,3 +39,7 @@ class Defaults:
     SESSION_SQLALCHEMY_SEQUENCE = None
     SESSION_SQLALCHEMY_SCHEMA = None
     SESSION_SQLALCHEMY_BIND_KEY = None
+
+    # DynamoDB settings
+    SESSION_DYNAMODB = None
+    SESSION_DYNAMODB_TABLE = "Sessions"

src/flask_session/dynamodb/__init__.py

@@ -0,0 +1 @@
+from .dynamodb import DynamoDBSession, DynamoDBSessionInterface  # noqa: F401

src/flask_session/dynamodb/dynamodb.py

@@ -0,0 +1,126 @@
+import warnings
+from datetime import datetime
+from datetime import timedelta as TimeDelta
+from decimal import Decimal
+from typing import Optional
+
+import boto3
+from mypy_boto3_dynamodb.service_resource import DynamoDBServiceResource
+from flask import Flask
+from itsdangerous import want_bytes
+
+from ..base import ServerSideSession, ServerSideSessionInterface
+from ..defaults import Defaults
+
+
+class DynamoDBSession(ServerSideSession):
+    pass
+
+
+class DynamoDBSessionInterface(ServerSideSessionInterface):
+    """A Session interface that uses dynamodb as backend. (`boto3` required)
+
+    :param client: A ``DynamoDBServiceResource`` instance.
+    :param key_prefix: A prefix that is added to all DynamoDB store keys.
+    :param use_signer: Whether to sign the session id cookie or not.
+    :param permanent: Whether to use permanent session or not.
+    :param sid_length: The length of the generated session id in bytes.
+    :param table_name: DynamoDB table name to store the session.
+
+    .. versionadded:: 0.6
+        The `sid_length` parameter was added.
+
+    .. versionadded:: 0.2
+        The `use_signer` parameter was added.
+    """
+
+    session_class = DynamoDBSession
+
+    def __init__(
+        self,
+        app: Flask,
+        client: Optional[DynamoDBServiceResource] = Defaults.SESSION_DYNAMODB,
+        key_prefix: str = Defaults.SESSION_KEY_PREFIX,
+        use_signer: bool = Defaults.SESSION_USE_SIGNER,
+        permanent: bool = Defaults.SESSION_PERMANENT,
+        sid_length: int = Defaults.SESSION_ID_LENGTH,
+        serialization_format: str = Defaults.SESSION_SERIALIZATION_FORMAT,
+        table_name: str = Defaults.SESSION_DYNAMODB_TABLE,
+    ):
+
+        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="http://localhost:8000",
+                region_name="us-west-2",
+                aws_access_key_id="dummy",
+                aws_secret_access_key="dummy",
+            )
+
+        try:
+            client.create_table(
+                AttributeDefinitions=[
+                    {"AttributeName": "id", "AttributeType": "S"},
+                ],
+                TableName=table_name,
+                KeySchema=[
+                    {"AttributeName": "id", "KeyType": "HASH"},
+                ],
+                BillingMode="PAY_PER_REQUEST",
+            )
+            client.meta.client.get_waiter("table_exists").wait(TableName=table_name)
+            client.meta.client.update_time_to_live(
+                TableName=self.table_name,
+                TimeToLiveSpecification={
+                    "Enabled": True,
+                    "AttributeName": "expiration",
+                },
+            )
+        except (AttributeError, client.meta.client.exceptions.ResourceInUseException):
+            # TTL already exists, or table already exists
+            pass
+
+        self.client = client
+        self.store = client.Table(table_name)
+        super().__init__(
+            app,
+            key_prefix,
+            use_signer,
+            permanent,
+            sid_length,
+            serialization_format,
+        )
+
+    def _retrieve_session_data(self, store_id: str) -> Optional[dict]:
+        # Get the saved session (document) from the database
+        document = self.store.get_item(Key={"id": store_id}).get("Item")
+        if document:
+            serialized_session_data = want_bytes(document.get("val").value)
+            return self.serializer.decode(serialized_session_data)
+        return None
+
+    def _delete_session(self, store_id: str) -> None:
+        self.store.delete_item(Key={"id": store_id})
+
+    def _upsert_session(
+        self, session_lifetime: TimeDelta, session: ServerSideSession, store_id: str
+    ) -> None:
+        storage_expiration_datetime = datetime.utcnow() + session_lifetime
+        # Serialize the session data
+        serialized_session_data = self.serializer.encode(session)
+
+        self.store.update_item(
+            Key={
+                "id": store_id,
+            },
+            UpdateExpression="SET val = :value, expiration = :exp",
+            ExpressionAttributeValues={
+                ":value": serialized_session_data,
+                ":exp": Decimal(storage_expiration_datetime.timestamp()),
+            },
+        )