---
- name: Find kernel cmdline file
  ansible.builtin.stat:
    path: "{{ item }}"
  loop: "{{ cgroups_cmdline_candidates }}"
  register: cmdline_stats

- name: Select kernel cmdline path
  ansible.builtin.set_fact:
    cgroups_cmdline_path: "{{ (cmdline_stats.results | selectattr('stat.exists') | map(attribute='stat.path') | list | first) | default('') }}"

- name: Fail when kernel cmdline file is missing
  ansible.builtin.fail:
    msg: "No kernel cmdline file found. Checked: {{ cgroups_cmdline_candidates | join(', ') }}"
  when: cgroups_cmdline_path | length == 0

- name: Read kernel cmdline
  ansible.builtin.slurp:
    path: "{{ cgroups_cmdline_path }}"
  register: cmdline_raw

- name: Parse kernel cmdline line
  ansible.builtin.set_fact:
    cgroups_cmdline_current: "{{ (cmdline_raw.content | b64decode).splitlines()[0] | default('') }}"

- name: Calculate missing cgroup params
  ansible.builtin.set_fact:
    cgroups_missing_params: "{{ cgroups_required_params | reject('in', cgroups_cmdline_current) | list }}"

- name: Update kernel cmdline when params are missing
  ansible.builtin.copy:
    dest: "{{ cgroups_cmdline_path }}"
    content: >-
      {{ cgroups_cmdline_current ~
         (' ' ~ (cgroups_missing_params | join(' ')) if (cgroups_missing_params | length) > 0 else '') ~
         '\n' }}
    mode: "0644"
  register: cmdline_update
  when: cgroups_missing_params | length > 0

- name: Reboot to apply cgroup settings
  ansible.builtin.reboot:
    msg: "Rebooting to apply cgroup kernel parameters"
    pre_reboot_delay: 3
    reboot_timeout: 600
  when: cmdline_update is changed and cgroups_reboot | bool

- name: Verify cgroup kernel parameters after reboot
  ansible.builtin.command: "cat /proc/cmdline"
  register: proc_cmdline
  changed_when: false

- name: Fail when cgroup params are missing (reboot required)
  ansible.builtin.fail:
    msg: "Missing cgroup params in /proc/cmdline: {{ cgroups_required_params | reject('in', proc_cmdline.stdout) | list }}. Reboot required."
  when: (cgroups_required_params | reject('in', proc_cmdline.stdout) | list) | length > 0