reduce how often list_containers is called (#196)

src/api-service/__app__/onefuzzlib/azure/containers.py

@@ -10,10 +10,20 @@ from typing import Any, Dict, Optional, Union, cast
 
 from azure.common import AzureHttpError, AzureMissingResourceHttpError
 from azure.storage.blob import BlobPermissions, ContainerPermissions
+from memoization import cached
 
 from .creds import get_blob_service
 
 
+@cached(ttl=5)
+def container_exists(name: str, account_id: Optional[str] = None) -> bool:
+    try:
+        get_blob_service(account_id).get_container_properties(name)
+        return True
+    except AzureHttpError:
+        return False
+
+
 def get_containers(account_id: Optional[str] = None) -> Dict[str, Dict[str, str]]:
     return {
         x.name: x.metadata
@@ -27,8 +37,7 @@ def get_container_metadata(
 ) -> Optional[Dict[str, str]]:
     try:
         result = get_blob_service(account_id).get_container_metadata(name)
-        if result:
-            return cast(Dict[str, str], result)
+        return cast(Dict[str, str], result)
     except AzureHttpError:
         pass
     return None