[AAP-65882] feat: switch to DAB Redis cache backend (#16471)

[AAP-65882] Switch to DAB Redis cache backend

Replace awx.main.cache.AWXRedisCache with the equivalent
ansible_base.lib.cache.redis_cache.DABRedisCache and remove the
now-redundant AWX driver. The DAB driver was migrated from this
exact code and provides the same fault-tolerant cache behavior.

Signed-off-by: Tomas Z <tznamena@redhat.com>

awx/main/cache.py

@@ -1,87 +0,0 @@
-import functools
-
-from django.conf import settings
-from django.core.cache.backends.base import DEFAULT_TIMEOUT
-from django.core.cache.backends.redis import RedisCache
-
-from redis.exceptions import ConnectionError, ResponseError, TimeoutError
-import socket
-
-# This list comes from what django-redis ignores and the behavior we are trying
-# to retain while dropping the dependency on django-redis.
-IGNORED_EXCEPTIONS = (TimeoutError, ResponseError, ConnectionError, socket.timeout)
-
-CONNECTION_INTERRUPTED_SENTINEL = object()
-
-
-def optionally_ignore_exceptions(func=None, return_value=None):
-    if func is None:
-        return functools.partial(optionally_ignore_exceptions, return_value=return_value)
-
-    @functools.wraps(func)
-    def wrapper(*args, **kwargs):
-        try:
-            return func(*args, **kwargs)
-        except IGNORED_EXCEPTIONS as e:
-            if settings.DJANGO_REDIS_IGNORE_EXCEPTIONS:
-                return return_value
-            raise e.__cause__ or e
-
-    return wrapper
-
-
-class AWXRedisCache(RedisCache):
-    """
-    We just want to wrap the upstream RedisCache class so that we can ignore
-    the exceptions that it raises when the cache is unavailable.
-    """
-
-    @optionally_ignore_exceptions
-    def add(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):
-        return super().add(key, value, timeout, version)
-
-    @optionally_ignore_exceptions(return_value=CONNECTION_INTERRUPTED_SENTINEL)
-    def _get(self, key, default=None, version=None):
-        return super().get(key, default, version)
-
-    def get(self, key, default=None, version=None):
-        value = self._get(key, default, version)
-        if value is CONNECTION_INTERRUPTED_SENTINEL:
-            return default
-        return value
-
-    @optionally_ignore_exceptions
-    def set(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):
-        return super().set(key, value, timeout, version)
-
-    @optionally_ignore_exceptions
-    def touch(self, key, timeout=DEFAULT_TIMEOUT, version=None):
-        return super().touch(key, timeout, version)
-
-    @optionally_ignore_exceptions
-    def delete(self, key, version=None):
-        return super().delete(key, version)
-
-    @optionally_ignore_exceptions
-    def get_many(self, keys, version=None):
-        return super().get_many(keys, version)
-
-    @optionally_ignore_exceptions
-    def has_key(self, key, version=None):
-        return super().has_key(key, version)
-
-    @optionally_ignore_exceptions
-    def incr(self, key, delta=1, version=None):
-        return super().incr(key, delta, version)
-
-    @optionally_ignore_exceptions
-    def set_many(self, data, timeout=DEFAULT_TIMEOUT, version=None):
-        return super().set_many(data, timeout, version)
-
-    @optionally_ignore_exceptions
-    def delete_many(self, keys, version=None):
-        return super().delete_many(keys, version)
-
-    @optionally_ignore_exceptions
-    def clear(self):
-        return super().clear()

awx/settings/defaults.py

@@ -448,7 +448,7 @@ DISPATCHER_SCHEDULE = {
 
 # Django Caching Configuration
 DJANGO_REDIS_IGNORE_EXCEPTIONS = True
-CACHES = {'default': {'BACKEND': 'awx.main.cache.AWXRedisCache', 'LOCATION': 'unix:///var/run/redis/redis.sock?db=1'}}
+CACHES = {'default': {'BACKEND': 'ansible_base.lib.cache.redis_cache.DABRedisCache', 'LOCATION': 'unix:///var/run/redis/redis.sock?db=1'}}
 
 ROLE_SINGLETON_USER_RELATIONSHIP = ''
 ROLE_SINGLETON_TEAM_RELATIONSHIP = ''