redis: Add username

Redis introduced ACL feature in 4.0.0, and this feature is supported by redis-py since 3.4.0[1]. When ACL is enabled, authentication requires username in addition to password.

This adds the username argument to Redis backend and Redis Sentinel backend, so that username can be passed in arguments along with password, instead of using client_kwargs and sentinel_kwargs.

[1] redis/redis-py@8df8cd5

Closes: #251
Pull-request: #251
Pull-request-sha: 172c195

Change-Id: I4c60316bafca0d600f26b13e867f2b569c1087f5

Author: kajinamit

docs/build/unreleased/251.rst

@@ -0,0 +1,7 @@
+.. change::
+    :tags: usecase, redis
+
+    Added new paramref:`.RedisBackend.username` parameter. This is used for
+    authentication in Redis when RBAC is enabled. Also added new
+    paramref:`.RedisSentinelBackend.username` parameter, which is used for
+    authentication in both Redis and Sentinel when RBAC is enabled.

dogpile/cache/backends/redis.py

@@ -45,11 +45,13 @@ class RedisBackend(BytesBackend):
     Arguments accepted in the arguments dictionary:
 
     :param url: string. If provided, will override separate
-     host/password/port/db params.  The format is that accepted by
+     host/username/password/port/db params.  The format is that accepted by
      ``StrictRedis.from_url()``.
 
     :param host: string, default is ``localhost``.
 
+    :param username: string, default is no username.
+
     :param password: string, default is no password.
 
     :param port: integer, default is ``6379``.
@@ -95,13 +97,16 @@ class RedisBackend(BytesBackend):
 
      .. versionadded:: 1.1.6  Added ``connection_kwargs`` parameter.
 
+     .. versionadded:: 1.3.1  Added ``username`` parameter.
+
     """
 
     def __init__(self, arguments):
         arguments = arguments.copy()
         self._imports()
         self.url = arguments.pop("url", None)
         self.host = arguments.pop("host", "localhost")
+        self.username = arguments.pop("username", None)
         self.password = arguments.pop("password", None)
         self.port = arguments.pop("port", 6379)
         self.db = arguments.pop("db", 0)
@@ -149,6 +154,7 @@ def _create_client(self):
             else:
                 args.update(
                     host=self.host,
+                    username=self.username,
                     password=self.password,
                     port=self.port,
                     db=self.db,
@@ -247,6 +253,10 @@ class RedisSentinelBackend(RedisBackend):
 
     Arguments accepted in the arguments dictionary:
 
+    :param username: string, default is no username.
+
+    :param password: string, default is no password.
+
     :param db: integer, default is ``0``.
 
     :param redis_expiration_time: integer, number of seconds after setting
@@ -292,6 +302,8 @@ class RedisSentinelBackend(RedisBackend):
      asynchronous runners, as they run in a different thread than the one
      used to create the lock.
 
+     .. versionadded:: 1.3.1  Added ``username`` parameter.
+
     """
 
     def __init__(self, arguments):
@@ -317,10 +329,12 @@ def _imports(self):
     def _create_client(self):
         sentinel_kwargs = {}
         sentinel_kwargs.update(self.sentinel_kwargs)
+        sentinel_kwargs.setdefault("username", self.username)
         sentinel_kwargs.setdefault("password", self.password)
 
         connection_kwargs = {}
         connection_kwargs.update(self.connection_kwargs)
+        connection_kwargs.setdefault("username", self.username)
         connection_kwargs.setdefault("password", self.password)
 
         if self.db is not None:

tests/cache/test_redis_backend.py

@@ -149,20 +149,22 @@ def test_connect_with_defaults(self, MockStrictRedis):
         # The defaults, used if keys are missing from the arguments dict.
         arguments = {
             "host": "localhost",
-            "password": None,
             "port": 6379,
             "db": 0,
         }
-        self._test_helper(MockStrictRedis, arguments, {})
+        expected = arguments.copy()
+        expected.update({"username": None, "password": None})
+        self._test_helper(MockStrictRedis, expected, arguments)
 
     def test_connect_with_basics(self, MockStrictRedis):
         arguments = {
             "host": "127.0.0.1",
-            "password": None,
             "port": 6379,
             "db": 0,
         }
-        self._test_helper(MockStrictRedis, arguments)
+        expected = arguments.copy()
+        expected.update({"username": None, "password": None})
+        self._test_helper(MockStrictRedis, expected, arguments)
 
     def test_connect_with_password(self, MockStrictRedis):
         arguments = {
@@ -171,17 +173,34 @@ def test_connect_with_password(self, MockStrictRedis):
             "port": 6379,
             "db": 0,
         }
+        expected = arguments.copy()
+        expected.update(
+            {
+                "username": None,
+            }
+        )
+        self._test_helper(MockStrictRedis, expected, arguments)
+
+    def test_connect_with_username_and_password(self, MockStrictRedis):
+        arguments = {
+            "host": "127.0.0.1",
+            "username": "redis",
+            "password": "some password",
+            "port": 6379,
+            "db": 0,
+        }
         self._test_helper(MockStrictRedis, arguments)
 
     def test_connect_with_socket_timeout(self, MockStrictRedis):
         arguments = {
             "host": "127.0.0.1",
             "port": 6379,
             "socket_timeout": 0.5,
-            "password": None,
             "db": 0,
         }
-        self._test_helper(MockStrictRedis, arguments)
+        expected = arguments.copy()
+        expected.update({"username": None, "password": None})
+        self._test_helper(MockStrictRedis, expected, arguments)
 
     def test_connect_with_connection_pool(self, MockStrictRedis):
         pool = Mock()

tox.ini

@@ -44,8 +44,8 @@ deps=
     {memcached}: python-memcached
     {memcached}: python-binary-memcached>=0.29.0
     {memcached}: pymemcache>=3.5.0
-    {redis}: redis
-    {redis_sentinel}: redis
+    {redis}: redis>=3.4.0
+    {redis_sentinel}: redis>=3.4.0
     {cov}: pytest-cov
 
 commands=