fixed redis_client

Author: JamesW1-NHS

lambdas/redis_sync/src/redis_cacher.py

@@ -2,7 +2,7 @@
 
 import json
 from transform_map import transform_map
-from common.clients import redis_client, logger
+from common.clients import get_redis_client, logger
 from common.s3_reader import S3Reader
 
 
@@ -24,6 +24,7 @@ def upload(bucket_name: str, file_key: str) -> dict:
             # Transform
             redis_mappings = transform_map(config_file_content, file_key)
 
+            redis_client = get_redis_client()
             for key, mapping in redis_mappings.items():
                 safe_mapping = {
                     k: json.dumps(v) if isinstance(v, list) else v

lambdas/redis_sync/src/redis_sync.py

@@ -1,6 +1,6 @@
 from event_read import read_event
 from record_processor import process_record
-from common.clients import redis_client, STREAM_NAME, logger
+from common.clients import get_redis_client, STREAM_NAME, logger
 from common.log_decorator import logging_decorator
 from common.s3_event import S3Event
 '''
@@ -35,7 +35,7 @@ def handler(event, _):
         no_records = "No records found in event"
         # check if the event requires a read, ie {"read": "my-hashmap"}
         if "read" in event:
-            return read_event(redis_client, event, logger)
+            return read_event(get_redis_client(), event, logger)
         elif "Records" in event:
             logger.info("Processing S3 event with %d records", len(event.get('Records', [])))
             s3_records = S3Event(event).get_s3_records()

lambdas/redis_sync/tests/test_redis_cacher.py

@@ -11,7 +11,7 @@ def setUp(self):
         self.mock_s3_reader = self.s3_reader_patcher.start()
         self.transform_map_patcher = patch("redis_cacher.transform_map")
         self.mock_transform_map = self.transform_map_patcher.start()
-        self.redis_client_patcher = patch("redis_cacher.redis_client")
+        self.redis_client_patcher = patch("common.clients.redis_client")
         self.mock_redis_client = self.redis_client_patcher.start()
         self.logger_info_patcher = patch("logging.Logger.info")
         self.mock_logger_info = self.logger_info_patcher.start()

lambdas/shared/src/common/clients.py

@@ -22,5 +22,12 @@
 dynamodb_resource = boto3_resource("dynamodb", region_name=REGION_NAME)
 dynamodb_client = boto3_client("dynamodb", region_name=REGION_NAME)
 
-logger.info(f"Connecting to Redis at {REDIS_HOST}:{REDIS_PORT}")
-redis_client = redis.StrictRedis(host=REDIS_HOST, port=REDIS_PORT, decode_responses=True)
+redis_client = None
+
+
+def get_redis_client():
+    global redis_client
+    if redis_client is None:
+        logger.info(f"Connecting to Redis at {REDIS_HOST}:{REDIS_PORT}")
+        redis_client = redis.StrictRedis(host=REDIS_HOST, port=REDIS_PORT, decode_responses=True)
+    return redis_client

lambdas/shared/tests/test_common/test_clients.py

@@ -56,13 +56,9 @@ def test_firehose_client(self):
         self.mock_boto3_client.assert_any_call("firehose", region_name=self.AWS_REGION)
 
     def test_redis_client(self):
-        ''' Test redis client is created with correct parameters '''
+        ''' Test redis client is not initialized on import '''
         importlib.reload(clients)
-        self.mock_redis.assert_called_once_with(
-            host=self.REDIS_HOST,
-            port=self.REDIS_PORT,
-            decode_responses=True
-        )
+        self.mock_redis.assert_not_called()
 
     def test_logging_setup(self):
         ''' Test logging is set up correctly '''
@@ -75,8 +71,10 @@ def test_logging_configuration(self):
         clients.logger.setLevel.assert_called_once_with("INFO")
 
     def test_redis_client_initialization(self):
-        ''' Test redis client initialization '''
+        ''' Test redis client is initialized exactly once even with multiple invocations'''
         importlib.reload(clients)
+        clients.get_redis_client()
+        clients.get_redis_client()
         self.mock_redis.assert_called_once_with(host=self.REDIS_HOST, port=self.REDIS_PORT, decode_responses=True)
         self.assertTrue(hasattr(clients, 'redis_client'))
         self.assertIsInstance(clients.redis_client, self.mock_redis.return_value.__class__)