ursula configuration migration script

scripts/migrations/configuration_v3_to_v4.py

@@ -0,0 +1,69 @@
+#!/usr/bin/env python
+
+"""
+ This file is part of nucypher.
+
+ nucypher is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Affero General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ nucypher is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU Affero General Public License for more details.
+
+ You should have received a copy of the GNU Affero General Public License
+ along with nucypher.  If not, see <https://www.gnu.org/licenses/>.
+"""
+
+import json
+
+import os
+import sys
+
+BACKUP_SUFFIX = '.old'
+OLD_VERSION = 3
+NEW_VERSION = 4
+
+
+def configuration_v3_to_v4(filepath: str):
+    """Updates configuration file v3 to v4 by remapping 'domains' to 'domain'"""
+
+    # Read + deserialize
+    with open(filepath, 'r') as file:
+        contents = file.read()
+    config = json.loads(contents)
+
+    try:
+        # Check we have version 1 indeed
+        existing_version = config['version']
+        if existing_version != OLD_VERSION:
+            raise RuntimeError(f'Existing configuration is not version 1; Got version {existing_version}')
+
+        # Make a copy of the original file
+        backup_filepath = filepath+BACKUP_SUFFIX
+        os.rename(filepath, backup_filepath)
+        print(f'Backed up existing configuration to {backup_filepath}')
+
+        # Apply updates
+        worker_address = config['worker_address']
+        del config['worker_address']  # deprecated
+        config['operator_address'] = worker_address
+        config['version'] = NEW_VERSION
+
+    except KeyError:
+        raise RuntimeError(f'Invalid {OLD_VERSION} configuration file.')
+
+    # Commit updates
+    with open(filepath, 'w') as file:
+        file.write(json.dumps(config, indent=4))
+    print('OK! Migrated configuration file from v3 -> v4.')
+
+
+if __name__ == "__main__":
+    try:
+        _python, filepath = sys.argv
+    except ValueError:
+        raise ValueError('Invalid command: Provide a single configuration filepath.')
+    configuration_v3_to_v4(filepath=filepath)