merge_variables: extended merge capabilities added (#11536)

* merge_variables: extended merge capabilities added This extension gives you more control over the variable merging process of the lookup plugin `merge_variables`. It closes the gap between Puppet's Hiera merging capabilities and the limitations of Ansible's default variable plugin `host_group_vars` regarding fragment-based value definition. You can now decide which merge strategy should be applied to dicts, lists, and other types. Furthermore, you can specify a merge strategy that should be applied in case of type conflicts. The default behavior of the plugin has been preserved so that it is fully backward-compatible with the already implemented state. Signed-off-by: Fiehe Christoph <c.fiehe@eurodata.de> * Update changelogs/fragments/11536-merge-variables-extended-merging-capabilities.yml Co-authored-by: Felix Fontein <felix@fontein.de> * Update plugins/lookup/merge_variables.py Co-authored-by: Felix Fontein <felix@fontein.de> * Periods added at the end of each choice description Signed-off-by: Fiehe Christoph <c.fiehe@eurodata.de> * Update plugins/lookup/merge_variables.py Co-authored-by: Mark <40321020+m-a-r-k-e@users.noreply.github.com> * ref: follow project standard for choice descriptions Signed-off-by: Fiehe Christoph <c.fiehe@eurodata.de> * ref: more examples added and refactoring Signed-off-by: Fiehe Christoph <c.fiehe@eurodata.de> * Update plugins/lookup/merge_variables.py Co-authored-by: Felix Fontein <felix@fontein.de> * ref: some more comments to examples added Signed-off-by: Fiehe Christoph <c.fiehe@eurodata.de> * fix: unused import removed Signed-off-by: Fiehe Christoph <c.fiehe@eurodata.de> * ref: re-add "merge" to strategy map Signed-off-by: Fiehe Christoph <c.fiehe@eurodata.de> * Update comments Signed-off-by: Fiehe Christoph <c.fiehe@eurodata.de> * Specification of transformations solely as string Signed-off-by: Fiehe Christoph <c.fiehe@eurodata.de> * Comments updated Signed-off-by: Fiehe Christoph <c.fiehe@eurodata.de> * ref: `append_rp` and `prepend_rp` removed feat: options dict for list transformations re-added feat: allow setting `keep` for dedup transformation with possible values: `first` (default) and `last` Signed-off-by: Fiehe Christoph <c.fiehe@eurodata.de> * ref: improve options documentation Signed-off-by: Fiehe Christoph <c.fiehe@eurodata.de> * ref: documentation improved, avoiding words like newer or older in merge description Signed-off-by: Fiehe Christoph <c.fiehe@eurodata.de> * Update plugins/lookup/merge_variables.py Co-authored-by: Felix Fontein <felix@fontein.de> * ref: "prio" replaced by "dict" Signed-off-by: Fiehe Christoph <c.fiehe@eurodata.de> * feat: two integration tests added Signed-off-by: Fiehe Christoph <c.fiehe@eurodata.de> --------- Signed-off-by: Fiehe Christoph <c.fiehe@eurodata.de> Co-authored-by: Fiehe Christoph <c.fiehe@eurodata.de> Co-authored-by: Felix Fontein <felix@fontein.de> Co-authored-by: Mark <40321020+m-a-r-k-e@users.noreply.github.com>
2026-03-22 05:09:12 +00:00 · 2026-03-19 22:45:44 +01:00 · 2026-03-19 22:45:44 +01:00 · dae2157bb7
commit dae2157bb7
parent 25b5655be7
6 changed files with 989 additions and 42 deletions
--- a/tests/integration/targets/lookup_merge_variables/test.yml
+++ b/tests/integration/targets/lookup_merge_variables/test.yml
@ -44,6 +44,62 @@
      vars:
        merged_dict: "{{ lookup('community.general.merge_variables', '^.+__merge_dict$') }}"

+    - name: Test shallow dict merge with 'list_merge=append' and 'dedup'
+      block:
+        - name: Print the merged dict
+          ansible.builtin.debug:
+            msg: "{{ merged_dict }}"
+
+        - name: Validate the merged dict
+          ansible.builtin.assert:
+            that: "merged_dict == expected_dict"
+          vars:
+            expected_dict:
+              a: "{{ testdict4__test['a'] }}"
+              b:
+                - 3
+                - 4
+                - "5": value
+                - 1
+                - 2
+      vars:
+        merged_dict: "{{
+          lookup(
+            'community.general.merge_variables', '__test', pattern_type='suffix', override='ignore',
+            dict_merge='shallow', list_merge='prepend', list_transformations=['dedup']) }}"
+
+    - name: Test deep dict merge with 'list_merge=prepend' and 'dedup' with 'keep=last'
+      block:
+        - name: Print the merged dict
+          ansible.builtin.debug:
+            msg: "{{ merged_dict }}"
+
+        - name: Validate the merged dict
+          ansible.builtin.assert:
+            that: "merged_dict == expected_dict"
+          vars:
+            expected_dict:
+              a:
+                a:
+                  x: low_value
+                  y: high_value
+                  list:
+                    - high_value
+                    - low_value
+                  z: high_value
+              b:
+                - 4
+                - "5": value
+                - 1
+                - 2
+                - 3
+      vars:
+        merged_dict: "{{
+          lookup(
+            'community.general.merge_variables', '__test', pattern_type='suffix', override='ignore',
+            dict_merge='deep', list_merge='prepend',
+            list_transformations=[{'name': 'dedup', 'options': {'keep': 'last'}}]) }}"
+
    # Test the behavior when no results are found
    - name: Test merge without results
      block: