scripts: op-mode: T3807: bugfix node.def generator

process_node() processes the XML tree in a fixed order, "node" before "tagNode"
before "leafNode". If the generator created a "node.def" file, it can no longer
be overwritten - else we would have some stale "node.def" files with an empty
help string (T2555). Without the fixed order this would resulted in a case
where we get a node and a tagNode with the same name, e.g. "show interfaces
ethernet" and "show interfaces ethernet eth0" that the node implementation
was not callable from the CLI, rendering this command useless (T3807).

This can be fixed by forcing the "node", "tagNode", "leafNode" order by sorting
the input XML file automatically (sorting from https://stackoverflow.com/a/46128043)
thus adding no additional overhead to the user.

1 files changed, 41 insertions, 16 deletions

diff --git a/scripts/build-command-op-templates b/scripts/build-command-op-templates
index a4d6d1d08..d4515b8db 100755
--- a/scripts/build-command-op-templates
+++ b/scripts/build-command-op-templates
@@ -29,13 +29,10 @@ import functools
 from lxml import etree as ET
 
 # Defaults
-
 validator_dir = "/opt/vyatta/libexec/validators"
 default_constraint_err_msg = "Invalid value"
 
-
 ## Get arguments
-
 parser = argparse.ArgumentParser(description='Converts new-style XML interface definitions to old-style command templates')
 parser.add_argument('--debug', help='Enable debug information output', action='store_true')
 parser.add_argument('INPUT_FILE', type=str, help="XML interface definition file")
@@ -50,7 +47,6 @@ output_dir = args.OUTPUT_DIR
 debug = args.debug
 
 ## Load and validate the inputs
-
 try:
     xml = ET.parse(input_file)
 except Exception as e:
@@ -76,7 +72,6 @@ if not os.access(output_dir, os.W_OK):
     sys.exit(1)
 
 ## If we got this far, everything must be ok and we can convert the file
-
 def make_path(l):
     path = functools.reduce(os.path.join, l)
     if debug:
@@ -125,21 +120,14 @@ def get_properties(p):
 def make_node_def(props, command):
     # XXX: replace with a template processor if it grows
     #      out of control
-
     node_def = ""
 
     if "help" in props:
         node_def += "help: {0}\n".format(props["help"])
-
-
     if "comp_help" in props:
         node_def += "allowed: {0}\n".format(props["comp_help"])
-
-
     if command is not None:
         node_def += "run: {0}\n".format(command.text)
-
-
     if debug:
         print("The contents of the node.def file:\n", node_def)
 
@@ -152,7 +140,6 @@ def process_node(n, tmpl_dir):
     props_elem = n.find("properties")
     children = n.find("children")
     command = n.find("command")
-
     name = n.get("name")
 
     node_type = n.tag
@@ -180,8 +167,7 @@ def process_node(n, tmpl_dir):
             inner_nodes = children.iterfind("*")
             for inner_n in inner_nodes:
                 process_node(inner_n, my_tmpl_dir)
-
-    if node_type == "tagNode":
+    elif node_type == "tagNode":
         if debug:
           print(f"Processing tagNode {name}")
 
@@ -211,7 +197,7 @@ def process_node(n, tmpl_dir):
             inner_nodes = children.iterfind("*")
             for inner_n in inner_nodes:
                 process_node(inner_n, my_tmpl_dir)
-    else:
+    elif node_type == "leafNode":
         # This is a leaf node
         if debug:
             print(f"Processing leaf node {name}")
@@ -219,9 +205,48 @@ def process_node(n, tmpl_dir):
         if not os.path.exists(nodedef_path) or os.path.getsize(nodedef_path) == 0:
             with open(nodedef_path, "w") as f:
                 f.write(make_node_def(props, command))
+    else:
+        print(f"Unknown node_type: {node_type}")
+
+
+def get_node_key(node, attr=None):
+    """ Return the sorting key of an xml node using tag and attributes """
+    if attr is None:
+        return '%s' % node.tag + ':'.join([node.get(attr)
+                                        for attr in sorted(node.attrib)])
+    if attr in node.attrib:
+        return '%s:%s' % (node.tag, node.get(attr))
+    return '%s' % node.tag
+
+
+def sort_children(node, attr=None):
+    """ Sort children along tag and given attribute. if attr is None, sort
+    along all attributes """
+    if not isinstance(node.tag, str):  # PYTHON 2: use basestring instead
+        # not a TAG, it is comment or DATA
+        # no need to sort
+        return
+    # sort child along attr
+    node[:] = sorted(node, key=lambda child: get_node_key(child, attr))
+    # and recurse
+    for child in node:
+        sort_children(child, attr)
 
 root = xml.getroot()
 
+# process_node() processes the XML tree in a fixed order, "node" before "tagNode"
+# before "leafNode". If the generator created a "node.def" file, it can no longer
+# be overwritten - else we would have some stale "node.def" files with an empty
+# help string (T2555). Without the fixed order this would resulted in a case
+# where we get a node and a tagNode with the same name, e.g. "show interfaces
+# ethernet" and "show interfaces ethernet eth0" that the node implementation
+# was not callable from the CLI, rendering this command useless (T3807).
+#
+# This can be fixed by forcing the "node", "tagNode", "leafNode" order by sorting
+# the input XML file automatically (sorting from https://stackoverflow.com/a/46128043)
+# thus adding no additional overhead to the user.
+sort_children(root, 'name')
+
 nodes = root.iterfind("*")
 for n in nodes:
     process_node(n, [output_dir])