node.clone plugin cleanup (#1639)

netsim/extra/node.clone/defaults.yml

@@ -4,8 +4,11 @@
 clone:
   node_name_pattern: "{name[:13]}-{id:02d}"                # Result should be a valid identifier, can use '-' in node names
 
-  attributes:
-    node:
-      clone: { type: int, min_value: 1, _required: True }  # Create N copies of this node anywhere it's used in groups or links
-      start: int                                           # Optional ID to start with, default 1
-      step: int                                            # Optional increment between clones, default 1
+#
+#  As the plugin runs before attribute validation, this structure is never checked. Left for documentation purposes
+#
+#  attributes:
+#    node:
+#      count: { type: int, min_value: 1, _required: True }  # Create N copies of this node anywhere it's used in groups or links
+#      start: int                                           # Optional ID to start with, default 1
+#      step: int                                            # Optional increment between clones, default 1

netsim/extra/node.clone/plugin.py

@@ -85,9 +85,14 @@ def update_links(topo_items: str, nodename: str, clones: list, topology: Box) ->
 def clone_node(node: Box, topology: Box) -> None:
   _p = { 'start': 1, 'step': 1 } + node.pop('clone',{})                      # Define cloning parameters
   if 'count' not in _p:
-    log.error("Node {node.name} missing required attribute clone.count",     # Not validated by Netlab yet
+    log.error("Node {node.name} missing required attribute clone.count",     # Not validated by Netlab
               category=AttributeError, module='node.clone')
     return
+  for attr in _p:
+    if not data.is_true_int(_p[attr]) or _p[attr]<=0:
+      log.error(f"Attribute {attr} for node.clone must be a positive int",
+                category=AttributeError, module='node.clone')
+      return
 
   if 'include' in node:                                                      # Check for components
     log.error("Cannot clone component {node.name}, only elementary nodes",