fix: ensure grub config rgeneration after grubby changes

defaults/main.yml

@@ -11,3 +11,5 @@ kernel_blacklist_modules:
 kernel_namespace_support_enabled: False
 kernel_coredump_enabled: True
 kernel_cgroup_v2_enabled: False
+
+kernel_grub_rebuild_force: False

handlers/main.yml

@@ -5,6 +5,15 @@
   become: True
   become_user: root
 
+- name: Rebuild grub config
+  command: "{{ item }}"
+  listen: __kernel_grub_rebuild
+  loop:
+    - grub2-mkconfig -o /boot/grub2/grub.cfg
+    - grub2-mkconfig -o /boot/efi/EFI/rocky/grub.cfg
+  become: True
+  become_user: root
+
 - name: Reboot server
   reboot:
     reboot_timeout: 600

molecule/rocky8/tests/test_default.py

@@ -35,7 +35,7 @@ def test_coredump_config(host):
 
 def test_cgroup_config(host):
     grub = host.file("/boot/grub2/grubenv")
-    proc = host.run("grep cgroup /proc/filesystems")
+    proc = host.run("mount -l | grep cgroup")
 
     assert grub.contains("systemd.unified_cgroup_hierarchy=1")
-    assert "cgroup2" in proc.stdout
+    assert "cgroup2 on /sys/fs/cgroup type cgroup2" in proc.stdout

tasks/cgroup.yml

@@ -17,12 +17,21 @@
     - __kernel_cgroup_exception.rc != 0
     - kernel_cgroup_v2_enabled | bool
   notify:
+    - __kernel_grub_rebuild
     - __kernel_server_restart
 
 - name: Disable cgroup v2 configuration
-  command: grubby --update-kernel=ALL --args="systemd.unified_cgroup_hierarchy=0"
+  command: grubby --update-kernel=ALL --remove-args="systemd.unified_cgroup_hierarchy"
   when:
     - __kernel_cgroup_exception.rc == 0
     - not kernel_cgroup_v2_enabled | bool
   notify:
+    - __kernel_grub_rebuild
     - __kernel_server_restart
+
+- name: Force rebuild grub config and reboot
+  command: /bin/true
+  notify:
+    - __kernel_grub_rebuild
+    - __kernel_server_restart
+  when: kernel_grub_rebuild_force | bool