Add Flask-Session version identification to Redis backends

.readthedocs.yaml

@@ -9,5 +9,6 @@ python:
     - method: pip
       path: .
 sphinx:
+  configuration: docs/conf.py
   builder: html
   fail_on_warning: true

CHANGES.rst

@@ -1,3 +1,11 @@
+Unreleased
+----------
+
+Added
+~~~~~~~
+-   Redis backend now identifies itself to Redis servers using the ``lib_name`` and ``lib_version`` parameters. The format follows redis-py conventions: ``lib_name`` is set to ``redis-py(flask-session_v<version>)`` and ``lib_version`` is set to the redis-py version.
+
+
 0.8.0 - 2024-03-26
 ------------------
 

src/flask_session/_utils.py

@@ -65,3 +65,72 @@ def wrapper(*args: Any, **kwargs: Any) -> Any:
         return wrapper
 
     return decorator
+
+
+def get_flask_session_version() -> str:
+    """Get the flask-session version string.
+
+    Returns:
+        flask-session version in the format 'major.minor.patch'
+        or 'unknown' if not available.
+    """
+    try:
+        from importlib.metadata import version
+
+        return version("flask-session")
+    except Exception:
+        # importlib.metadata not available or package metadata not found
+        # Fallback to __version__ from __init__.py
+        try:
+            from flask_session import __version__
+
+            return __version__
+        except (ImportError, AttributeError):
+            return "unknown"
+
+
+def get_redis_py_version() -> str:
+    """Get the redis-py version string.
+
+    Returns:
+        redis-py version in the format 'major.minor.patch'
+        or 'unknown' if not available.
+    """
+    try:
+        from importlib.metadata import version
+
+        return version("redis")
+    except Exception:
+        return "unknown"
+
+
+def add_redis_version_info(kwargs):
+    """Add version identification for redis-py client.
+
+    This function adds library identification to Redis connection kwargs,
+    allowing Redis operators to see which library is using the connection.
+
+    Follows the format: lib_name='redis-py(flask-session_v0.8.0)'
+    and lib_version='<redis-py version>'.
+
+    Only sets lib_name and lib_version if not already provided by user,
+    ensuring user-provided values are never overridden.
+
+    Args:
+        kwargs: Dictionary of keyword arguments to pass to Redis client.
+                Will be modified in-place to add 'lib_name' and 'lib_version'
+                if they are not already present.
+
+    Example:
+        >>> kwargs = {}
+        >>> add_redis_version_info(kwargs)
+        >>> kwargs['lib_name']
+        'redis-py(flask-session_v0.8.0)'
+        >>> kwargs['lib_version']
+        '5.0.8'
+    """
+    if "lib_name" not in kwargs:
+        flask_session_ver = get_flask_session_version()
+        redis_py_ver = get_redis_py_version()
+        kwargs["lib_name"] = f"redis-py(flask-session_v{flask_session_ver})"
+        kwargs["lib_version"] = redis_py_ver

src/flask_session/redis/redis.py

@@ -5,7 +5,7 @@
 from flask import Flask
 from redis import Redis
 
-from .._utils import total_seconds
+from .._utils import add_redis_version_info, total_seconds
 from ..base import ServerSideSession, ServerSideSessionInterface
 from ..defaults import Defaults
 
@@ -53,7 +53,10 @@ def __init__(
                 RuntimeWarning,
                 stacklevel=1,
             )
-            client = Redis()
+            # Add version identification for redis-py client
+            kwargs = {}
+            add_redis_version_info(kwargs)
+            client = Redis(**kwargs)
         self.client = client
         super().__init__(
             app, key_prefix, use_signer, permanent, sid_length, serialization_format

tests/test_redis.py

@@ -2,9 +2,11 @@
 from contextlib import contextmanager
 
 import flask
-from flask_session.redis import RedisSession
 from redis import Redis
 
+from flask_session._utils import get_flask_session_version, get_redis_py_version
+from flask_session.redis import RedisSession
+
 
 class TestRedisSession:
     """This requires package: redis"""
@@ -40,3 +42,38 @@ def test_redis_default(self, app_utils):
                     json.loads(byte_string.decode("utf-8")) if byte_string else {}
                 )
                 assert stored_session.get("value") == "44"
+
+    def test_redis_adds_version_info(self, app_utils):
+        """Test that RedisSessionInterface adds Flask-Session version info when creating default client."""
+        with self.setup_redis():
+            # Don't provide a Redis client, let it create one with version info
+            app = app_utils.create_app({"SESSION_TYPE": "redis"})
+
+            with app.test_request_context():
+                # Access the session interface to trigger client creation
+                session_interface = app.session_interface
+
+                # Check that lib_name and lib_version were set in connection pool
+                conn_kwargs = session_interface.client.connection_pool.connection_kwargs
+                flask_session_ver = get_flask_session_version()
+                expected_lib_name = f"redis-py(flask-session_v{flask_session_ver})"
+                assert conn_kwargs.get("lib_name") == expected_lib_name
+                assert conn_kwargs.get("lib_version") == get_redis_py_version()
+
+    def test_redis_respects_custom_version_info(self, app_utils):
+        """Test that custom lib_name and lib_version are not overridden."""
+        with self.setup_redis():
+            # Create a Redis client with custom version info
+            custom_client = Redis(lib_name="MyCustomApp", lib_version="1.2.3")
+
+            app = app_utils.create_app(
+                {"SESSION_TYPE": "redis", "SESSION_REDIS": custom_client}
+            )
+
+            with app.test_request_context():
+                session_interface = app.session_interface
+
+                # Check that custom values were preserved
+                conn_kwargs = session_interface.client.connection_pool.connection_kwargs
+                assert conn_kwargs.get("lib_name") == "MyCustomApp"
+                assert conn_kwargs.get("lib_version") == "1.2.3"