Fix: SDK error when retrieving fallback private key, but the symlink …

…was dead. (#33)

Solution: We add a check to determine if it is a symlink and if it is dead. In this case, we unlink it.

Co-authored-by: Olivier Desenfans <desenfans.olivier@gmail.com>

src/aleph/sdk/chains/common.py

@@ -7,6 +7,9 @@
 
 from aleph.sdk.conf import settings
 
+import logging
+
+logger = logging.getLogger(__name__)
 
 def get_verification_buffer(message: Dict) -> bytes:
     """
@@ -120,7 +123,13 @@ def get_fallback_private_key(path: Optional[Path] = None) -> bytes:
         path.write_bytes(private_key)
 
         default_key_path = path.parent / "default.key"
+
+        # If the symlink exists but does not point to a file, delete it.
+        if default_key_path.is_symlink() and not default_key_path.resolve().exists():
+            default_key_path.unlink()
+            logger.warning("The symlink to the private key is broken")
+
+        # Create a symlink to use this key by default
         if not default_key_path.exists():
-            # Create a symlink to use this key by default
             default_key_path.symlink_to(path)
     return private_key