ini inventory now requires extension

but has option to enable previous behaviour

changelogs/fragments/ini_extension.yml

@@ -0,0 +1,2 @@
+minor_changes:
+  - ini inventory plugin now has 'allowed_extensions' option to specify which extensions the plugin will consider as an inventory source. It defaults to .ini and no extension, which should cover most usage. To make it consider all files, for full backwards compatibility, set to an empty list.

lib/ansible/plugins/inventory/ini.py

@@ -2,10 +2,22 @@
 # GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
 from __future__ import annotations
 
-DOCUMENTATION = """
+DOCUMENTATION = '''
     name: ini
     version_added: "2.4"
     short_description: Uses an Ansible INI file as inventory source.
+    options:
+      allowed_extensions:
+        description: What extensions this plugin will activate for.
+        version_added: "2.19"
+        default: ['ini', '']
+        type: list
+        elements: str
+        ini:
+           - section: inventory_plugin_ini
+             key: allowed_extensions
+        env:
+           - name: ANSIBLE_INVENTORY_PLUGIN_INI_EXT
     description:
         - INI file based inventory, sections are groups or group related with special C(:modifiers).
         - Entries in sections C([group_1]) are hosts, members of the group.
@@ -27,9 +39,12 @@ DOCUMENTATION = """
         - Enabled in configuration by default.
         - Consider switching to YAML format for inventory sources to avoid confusion on the actual type of a variable.
           The YAML inventory plugin processes variable values consistently and correctly.
-"""
+        - Passing an empty string `''` as part of O(allowed_extensions) allows matching files without extension.
+        - Making O(allowed_extensions) and empty list or None will enable 'any extension' to be considered.
+          This would make the inventory plugin match previous behaviour.
+'''
 
-EXAMPLES = """# fmt: ini
+EXAMPLES = '''fmt: ini
 # Example 1
 [web]
 host1
@@ -70,12 +85,14 @@ host4
 [g2]
 host4 # same host as above, but member of 2 groups, will inherit vars from both
       # inventory hostnames are unique
-"""
+'''
 
 import ast
 import re
 import warnings
 
+from pathlib import Path
+
 from ansible.inventory.group import to_safe_group_name
 from ansible.plugins.inventory import BaseFileInventoryPlugin
 
@@ -100,6 +117,15 @@ class InventoryModule(BaseFileInventoryPlugin):
         self.patterns = {}
         self._filename = None
 
+    def verify_file(self, path):
+
+        valid = super().verify_file(path)
+        p = Path(path)
+        allowed = self.get_option('allowed_extensions')
+        if valid and allowed and p.suffix[1:] not in allowed:
+            valid = False
+        return valid
+
     def parse(self, inventory, loader, path, cache=True):
 
         super(InventoryModule, self).parse(inventory, loader, path)