fix(connection, iam-auth): host, port connect() params override describe_cluster response

Author: Brooke-white

redshift_connector/__init__.py

@@ -125,7 +125,7 @@ def connect(
     database: str,
     password: str,
     port: int = 5439,
-    host: str = "localhost",
+    host: str = "",
     source_address: typing.Optional[str] = None,
     unix_sock: typing.Optional[str] = None,
     ssl: bool = True,

redshift_connector/iam_helper.py

@@ -377,9 +377,11 @@ def set_cluster_credentials(
             else:
                 client = boto3.client(service_name="redshift", **session_credentials)
 
-            response = client.describe_clusters(ClusterIdentifier=info.cluster_identifier)
-            info.host = response["Clusters"][0]["Endpoint"]["Address"]
-            info.port = response["Clusters"][0]["Endpoint"]["Port"]
+            if info.host is None or info.host == "" or info.port is None or info.port == "":
+                response = client.describe_clusters(ClusterIdentifier=info.cluster_identifier)
+
+                info.host = response["Clusters"][0]["Endpoint"]["Address"]
+                info.port = response["Clusters"][0]["Endpoint"]["Port"]
 
             # temporary credentials are cached by redshift_connector and will be used if they have not expired
             cache_key: str = IamHelper.get_credentials_cache_key(info)