cli: add support for deprecated tower-cli aliases in py2

awxkit/awxkit/cli/client.py

@@ -170,9 +170,9 @@ class CLI(object):
             if formatted:
                 print(utils.to_str(formatted), file=self.stdout)
         else:
-            self.parser.print_help()
-
-            if six.PY2 and not self.help:
+            if six.PY3:
+                self.parser.print_help()
+            elif six.PY2 and not self.help:
                 # Unfortunately, argparse behavior between py2 and py3
                 # changed in a notable way when required subparsers
                 # have invalid (or missing) arguments specified

awxkit/awxkit/cli/resource.py

@@ -137,9 +137,10 @@ def parse_resource(client, skip_deprecated=False):
 
             # argparse aliases are *only* supported in Python3 (not 2.7)
             kwargs = {}
-            if not skip_deprecated and PY3:
+            if not skip_deprecated:
                 if k in DEPRECATED_RESOURCES:
                     kwargs['aliases'] = [DEPRECATED_RESOURCES[k]]
+
             client.subparsers[k] = subparsers.add_parser(
                 k, help='', **kwargs
             )

awxkit/awxkit/cli/utils.py

@@ -5,6 +5,8 @@ import os
 import sys
 import threading
 
+import six
+
 _color = threading.local()
 _color.enabled = True
 
@@ -36,6 +38,29 @@ class CustomRegistryMeta(type):
 
 class HelpfulArgumentParser(ArgumentParser):
 
+    def __init__(self, *args, **kwargs):
+        super(HelpfulArgumentParser, self).__init__(*args, **kwargs)
+        if six.PY2:
+            # backport parser aliases support to py2
+            # see: https://github.com/python/cpython/commit/fd311a712d5876c3a3efff265978452eea759f85
+            SubParsersAction = self._registries['action']['parsers']
+
+            class _SubParsersAction(SubParsersAction):
+
+                def add_parser(self, name, **kwargs):
+                    aliases = kwargs.pop('aliases', [])
+                    parser = super(_SubParsersAction, self).add_parser(name, **kwargs)
+                    if aliases:
+                        self._choices_actions[-1].metavar = ' '.join([
+                            name,
+                            '({})'.format(', '.join(aliases))
+                        ])
+                    for alias in aliases:
+                        self._name_parser_map[alias] = parser
+                    return parser
+
+            self._registries['action']['parsers'] = _SubParsersAction
+
     def error(self, message):  # pragma: nocover
         """Prints a usage message incorporating the message to stderr and
         exits.