Don't expand config to empty strings

npbackup/configuration.py

@@ -376,6 +376,8 @@ def evaluate_variables(repo_config: dict, full_config: dict) -> dict:
 
             if "${HOSTNAME}" in value:
                 value = value.replace("${HOSTNAME}", platform.node())
+        if value == "":
+            value = None
         return value
 
     # We need to make a loop to catch all nested variables (ie variable in a variable)

npbackup/restic_metrics/__init__.py

@@ -178,7 +178,8 @@ def restic_json_to_prometheus(
     """
     _labels = []
     for key, value in labels.items():
-        _labels.append(f'{key.strip()}="{value.strip()}"')
+        if value:
+            _labels.append(f'{key.strip()}="{value.strip()}"')
     labels = ",".join(_labels)
 
     # Take last line of restic output