[libvirt_manager] Preserve existing inventory children when regenerating all-group.yml

The all-group.yml inventory file is regenerated during deployment, but this
causes loss of inventory groups from previous operations (e.g., BGP routers,
spines, leafs, undercloud nodes). This change extracts the all-group creation
logic into a separate task file that checks for an existing file, slurps its
content, generates the new template, and then recursively merges the children
from both old and new files. This ensures all inventory groups are preserved
across multiple deployment phases.

Co-Authored-By: Claude Sonnet 4.5 <[email protected]>
Signed-off-by: Eduardo Olivares <[email protected]>

Author: eduolivares

roles/libvirt_manager/tasks/create_all_group_inventory.yml

@@ -0,0 +1,37 @@
+- name: Check if all-group.yml already exists
+  ansible.builtin.stat:
+    path: "{{ cifmw_libvirt_manager_basedir }}/reproducer-inventory/all-group.yml"
+  register: _all_group_stat
+
+- name: Slurp existing all-group.yml if it exists
+  when: _all_group_stat.stat.exists
+  ansible.builtin.slurp:
+    src: "{{ cifmw_libvirt_manager_basedir }}/reproducer-inventory/all-group.yml"
+  register: _all_group_slurped
+
+- name: Create new "all" group inventory file from template
+  ansible.builtin.template:
+    dest: "{{ cifmw_libvirt_manager_basedir }}/reproducer-inventory/all-group.yml"
+    src: "all-inventory.yml.j2"
+    mode: "0644"
+
+- name: Merge existing children with newly generated content
+  when: _all_group_stat.stat.exists
+  block:
+    - name: Slurp newly created all-group.yml
+      ansible.builtin.slurp:
+        src: "{{ cifmw_libvirt_manager_basedir }}/reproducer-inventory/all-group.yml"
+      register: _new_all_group_slurped
+
+    - name: Write merged all-group.yml
+      vars:
+        _existing_all_group: "{{ _all_group_slurped['content'] | b64decode | from_yaml }}"
+        _existing_all_group_dict:
+          all:
+            children: "{{ _existing_all_group.all.children }}"
+        _new_all_group: "{{ _new_all_group_slurped['content'] | b64decode | from_yaml }}"
+        _merged_all_group: "{{ _existing_all_group_dict | combine(_new_all_group, recursive=true) }}"
+      ansible.builtin.copy:
+        dest: "{{ cifmw_libvirt_manager_basedir }}/reproducer-inventory/all-group.yml"
+        content: "{{ _merged_all_group | to_nice_yaml }}"
+        mode: "0644"

roles/libvirt_manager/tasks/deploy_layout.yml

@@ -101,10 +101,7 @@
     label: "{{ item }}"
 
 - name: Create "all" group inventory file
-  ansible.builtin.template:
-    dest: "{{ cifmw_libvirt_manager_basedir }}/reproducer-inventory/all-group.yml"
-    src: "all-inventory.yml.j2"
-    mode: "0644"
+  ansible.builtin.include_tasks: create_all_group_inventory.yml
 
 - name: Ensure storage pool is present.
   when: