cache/redis: make keyset keyname configurable (#1036) (#1074)

* FEATURE: make ansible_cache_keys name configurable

* REFACTOR: rename cache_keys to keyset

* FEATURE: add changelog fragment

* Update changelogs/fragments/1036-redis-cache-keyset-name.yaml

Co-authored-by: Felix Fontein <felix@fontein.de>

* Set version_added in plugins/cache/redis.py

Co-authored-by: Felix Fontein <felix@fontein.de>

Co-authored-by: Benjamin Pereto <benjamin@sandchaschte.ch>
Co-authored-by: Felix Fontein <felix@fontein.de>
(cherry picked from commit 873f1fb7fd)

Co-authored-by: Benjamin Pereto <dev@sandchaschte.ch>

changelogs/fragments/1036-redis-cache-keyset-name.yaml

@@ -0,0 +1,3 @@
+minor_changes:
+  - redis cache plugin - make the redis cache keyset name configurable
+    (https://github.com/ansible-collections/community.general/pull/1036).

plugins/cache/redis.py

@@ -32,6 +32,15 @@ DOCUMENTATION = '''
         ini:
           - key: fact_caching_prefix
             section: defaults
+      _keyset_name:
+        description: User defined name for cache keyset name.
+        default: ansible_cache_keys
+        env:
+          - name: ANSIBLE_CACHE_REDIS_KEYSET_NAME
+        ini:
+          - key: fact_caching_redis_keyset_name
+            section: defaults
+        version_added: 1.3.0
       _timeout:
         default: 86400
         description: Expiration timeout in seconds for the cache plugin data. Set to 0 to never expire
@@ -78,6 +87,7 @@ class CacheModule(BaseCacheModule):
                 uri = self.get_option('_uri')
             self._timeout = float(self.get_option('_timeout'))
             self._prefix = self.get_option('_prefix')
+            self._keys_set = self.get_option('_keyset_name')
         except KeyError:
             display.deprecated('Rather than importing CacheModules directly, '
                                'use ansible.plugins.loader.cache_loader',
@@ -86,6 +96,7 @@ class CacheModule(BaseCacheModule):
                 uri = C.CACHE_PLUGIN_CONNECTION
             self._timeout = float(C.CACHE_PLUGIN_TIMEOUT)
             self._prefix = C.CACHE_PLUGIN_PREFIX
+            self._keys_set = 'ansible_cache_keys'
 
         self._cache = {}
         kw = {}
@@ -96,7 +107,6 @@ class CacheModule(BaseCacheModule):
 
         connection = uri.split(':')
         self._db = StrictRedis(*connection, **kw)
-        self._keys_set = 'ansible_cache_keys'
 
     def _make_key(self, key):
         return self._prefix + key