To ease transition, handle legacy format with kinto-wizard 4.0

kinto_wizard/validate.py

@@ -42,7 +42,13 @@ def validate_schema(data, schema, ignore_fields=[]):
 
 def validate_export(config):
     everything_is_fine = True
-    buckets = config.get("buckets", {})
+    if 'buckets' in config:
+        buckets = config.get("buckets", {})
+    else:  # pragma: no cover
+        # Legacy for file before kinto-wizard 3.0
+        logger.warning("Your file seems to be in legacy format. "
+                       "Please add a `buckets:` root namespace.")
+        buckets = config
     for bid, bucket in buckets.items():
         logger.info(f"- Bucket {bid}")
         bucket_collections = bucket.get('collections', {})

kinto_wizard/yaml2kinto.py

@@ -21,7 +21,13 @@ async def initialize_server(async_client, config, bucket=None, collection=None,
         # We don't need to load it because we will override it nevertheless.
         current_server_buckets = {}
     # 2. For each bucket
-    buckets = config.get("buckets", {})
+    if 'buckets' in config:
+        buckets = config.get("buckets", {})
+    else:  # pragma: no cover
+        # Legacy for file before kinto-wizard 3.0
+        logger.warning("Your file seems to be in legacy format. "
+                       "Please add a `buckets:` root namespace.")
+        buckets = config
     with async_client.batch() as batch:
         for bucket_id, bucket in buckets.items():
             # Skip buckets that we don't want to import.