Merge pull request #3266 from MarekBleschke/feature/redis_sentinel_cofig

settings for redis sentinel

src/ralph/settings/base.py

@@ -287,9 +287,30 @@ def str_to_bool(s: str) -> bool:
         }
     })
 
+REDIS_MASTER_IP = None
+REDIS_MASTER_PORT = None
+
+REDIS_SENTINEL_ENABLED = bool_from_env('REDIS_SENTINEL_ENABLED', False)
+if REDIS_SENTINEL_ENABLED:
+    from redis.sentinel import Sentinel
+
+    # REDIS_SENTINEL_HOSTS env variable format: host_1:port;host_2:port
+    REDIS_SENTINEL_HOSTS = os.environ['REDIS_SENTINEL_HOSTS'].split(';')
+    REDIS_CLUSTER_NAME = os.environ['REDIS_CLUSTER_NAME']
+
+    sentinel = Sentinel(
+        [tuple(s_host.split(':')) for s_host in REDIS_SENTINEL_HOSTS],
+        socket_timeout=float(
+            os.environ.get('REDIS_SENTINEL_SOCKET_TIMEOUT', 0.2)
+        )
+    )
+    REDIS_MASTER_IP, REDIS_MASTER_PORT = sentinel.discover_master(
+        REDIS_CLUSTER_NAME
+    )
+
 REDIS_CONNECTION = {
-    'HOST': os.environ.get('REDIS_HOST', 'localhost'),
-    'PORT': os.environ.get('REDIS_PORT', '6379'),
+    'HOST': REDIS_MASTER_IP or os.environ.get('REDIS_HOST', 'localhost'),
+    'PORT': REDIS_MASTER_PORT or os.environ.get('REDIS_PORT', '6379'),
     'DB': int(os.environ.get('REDIS_DB', 0)),
     'PASSWORD': os.environ.get('REDIS_PASSWORD', ''),
     # timeout for executing commands