Add toggle to control invalid character substitution in group names (#52748)

* make add_group return proper name
* ensure central transform/check
* added 'silent' option to avoid spamming current users
  those already using the plugins were used to the transformations, so no need to alert them
* centralized valid var names
* dont display dupes
* comment on regex
* added regex tests
  ini and script will now warn about deprecation
* more complete errormsg

lib/ansible/plugins/inventory/__init__.py

@@ -21,10 +21,10 @@ __metaclass__ = type
 
 import hashlib
 import os
-import re
 import string
 
 from ansible.errors import AnsibleError, AnsibleParserError
+from ansible.inventory.group import to_safe_group_name as original_safe
 from ansible.parsing.utils.addresses import parse_address
 from ansible.plugins import AnsiblePlugin
 from ansible.plugins.cache import InventoryFileCacheModule
@@ -37,13 +37,11 @@ from ansible.utils.display import Display
 
 display = Display()
 
-_SAFE_GROUP = re.compile("[^A-Za-z0-9_]")
-
 
 # Helper methods
 def to_safe_group_name(name):
-    ''' Converts 'bad' characters in a string to underscores so they can be used as Ansible hosts or groups '''
-    return _SAFE_GROUP.sub("_", name)
+    # placeholder for backwards compat
+    return original_safe(name, force=True, silent=True)
 
 
 def detect_range(line=None):
@@ -319,6 +317,7 @@ class Constructable(object):
             self.templar.set_available_variables(variables)
             for group_name in groups:
                 conditional = "{%% if %s %%} True {%% else %%} False {%% endif %%}" % groups[group_name]
+                group_name = to_safe_group_name(group_name)
                 try:
                     result = boolean(self.templar.template(conditional))
                 except Exception as e:
@@ -327,8 +326,8 @@ class Constructable(object):
                     continue
 
                 if result:
-                    # ensure group exists
-                    self.inventory.add_group(group_name)
+                    # ensure group exists, use sanatized name
+                    group_name = self.inventory.add_group(group_name)
                     # add host to group
                     self.inventory.add_child(group_name, host)