Add a toggle for the leading separator for keyed_groups (#60882)

* Add a toggle for the leading separator for keyed_groups if no prefix is given

* changelog

* Add tests for backward compatibility and the new toggle

changelogs/fragments/60882-keyed_groups-leading-separator-toggle.yaml

@@ -0,0 +1,2 @@
+minor_changes:
+  - constructed - Add a toggle to allow the separator to be omitted if no prefix has been provided.

lib/ansible/plugins/doc_fragments/constructed.py

@@ -39,4 +39,15 @@ options:
         key: use_extra_vars
     env:
       - name: ANSIBLE_INVENTORY_USE_EXTRA_VARS
+  leading_separator:
+    description:
+      - Use in conjunction with keyed_groups.
+      - By default, a keyed group that does not have a prefix or a separator provided will have a name that starts with an underscore.
+      - This is because the default prefix is "" and the default separator is "_".
+      - Set this option to False to omit the leading underscore (or other separator) if no prefix is given.
+      - If the group name is derived from a mapping the separator is still used to concatenate the items.
+      - To not use a separator in the group name at all, set the separator for the keyed group to an empty string instead.
+    type: boolean
+    default: True
+    version_added: '2.11'
 '''

lib/ansible/plugins/inventory/__init__.py

@@ -443,6 +443,8 @@ class Constructable(object):
                             raise AnsibleParserError("Invalid group name format, expected a string or a list of them or dictionary, got: %s" % type(key))
 
                         for bare_name in new_raw_group_names:
+                            if prefix == '' and self.get_option('leading_separator') is False:
+                                sep = ''
                             gname = self._sanitize_group_name('%s%s%s' % (prefix, sep, bare_name))
                             result_gname = self.inventory.add_group(gname)
                             self.inventory.add_host(host, result_gname)

test/integration/targets/inventory_constructed/aliases

@@ -0,0 +1 @@
+shippable/posix/group3

test/integration/targets/inventory_constructed/constructed.yml

@@ -0,0 +1,19 @@
+plugin: constructed
+keyed_groups:
+  - key: hostvar0
+  - key: hostvar1
+  - key: hostvar2
+
+  - key: hostvar0
+    separator: 'separator'
+  - key: hostvar1
+    separator: 'separator'
+  - key: hostvar2
+    separator: 'separator'
+
+  - key: hostvar0
+    prefix: 'prefix'
+  - key: hostvar1
+    prefix: 'prefix'
+  - key: hostvar2
+    prefix: 'prefix'

test/integration/targets/inventory_constructed/no_leading_separator_constructed.yml

@@ -0,0 +1,20 @@
+plugin: constructed
+keyed_groups:
+  - key: hostvar0
+  - key: hostvar1
+  - key: hostvar2
+
+  - key: hostvar0
+    separator: 'separator'
+  - key: hostvar1
+    separator: 'separator'
+  - key: hostvar2
+    separator: 'separator'
+
+  - key: hostvar0
+    prefix: 'prefix'
+  - key: hostvar1
+    prefix: 'prefix'
+  - key: hostvar2
+    prefix: 'prefix'
+leading_separator: False

test/integration/targets/inventory_constructed/runme.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+
+set -ex
+
+ansible-inventory -i static_inventory.yml -i constructed.yml --graph | tee out.txt
+
+grep '@_hostvalue1' out.txt
+grep '@_item0' out.txt
+grep '@_key0_value0' out.txt
+grep '@prefix_hostvalue1' out.txt
+grep '@prefix_item0' out.txt
+grep '@prefix_key0_value0' out.txt
+grep '@separatorhostvalue1' out.txt
+grep '@separatoritem0' out.txt
+grep '@separatorkey0separatorvalue0' out.txt
+
+ansible-inventory -i static_inventory.yml -i no_leading_separator_constructed.yml --graph | tee out.txt
+
+grep '@hostvalue1' out.txt
+grep '@item0' out.txt
+grep '@key0_value0' out.txt
+grep '@key0separatorvalue0' out.txt
+grep '@prefix_hostvalue1' out.txt
+grep '@prefix_item0' out.txt
+grep '@prefix_key0_value0' out.txt

test/integration/targets/inventory_constructed/static_inventory.yml

@@ -0,0 +1,8 @@
+all:
+  hosts:
+    host0:
+      hostvar0:
+        key0: value0
+      hostvar1: hostvalue1
+      hostvar2:
+        - item0

test/units/plugins/inventory/test_constructed.py

@@ -33,6 +33,7 @@ def inventory_module():
     r = InventoryModule()
     r.inventory = InventoryData()
     r.templar = Templar(None)
+    r._options = {'leading_separator': True}
     return r