Implement GRUB modification process

In some cases it might be required to supply extra kernel options
through GRUB modification. Good example of that is enablement
of hugepages [1].

Adding variable `openstack_host_grub_options` should allow to
manage GRUB-related options reliably and out-of-the-box.

[1] https://docs.openstack.org/nova/latest/admin/huge-pages.html#enabling-huge-pages-on-the-host

Change-Id: I148ed1760d841dd99bc1e075b6200d6d7e835530
Signed-off-by: Dmitriy Rabotyagov <dmitriy.rabotyagov@cleura.com>

defaults/main.yml

@@ -66,6 +66,17 @@ openstack_host_blacklist_kernel_modules: []
 # Command to update initramfs
 openstack_host_initramfs_command: "{{ _openstack_host_initramfs_command | default('true') }}"
 
+# Custom options to define in GRUB_CMDLINE_LINUX_DEFAULT
+# openstack_host_custom_grub_options:
+#   - key: hugepagesz
+#     value: 2MB
+#   - key: nomodeset
+#   - key: gfxpayload
+#     value: text
+#     state: absent
+openstack_host_custom_grub_options: {}
+openstack_host_update_grub_command: "{{ _openstack_host_update_grub_command }}"
+
 # Overridable package list is composed of the old override
 # named user_package_list and the standard defaults _openstack_hosts_package_list
 openstack_hosts_package_list: "{{ _openstack_hosts_package_list + (user_package_list | default([])) }}"

handlers/main.yml

@@ -16,6 +16,9 @@
 - name: Update initramfs  # noqa: no-changed-when
   ansible.builtin.command: "{{ openstack_host_initramfs_command }}"
 
+- name: Update GRUB  # noqa: no-changed-when
+  ansible.builtin.command: "{{ openstack_host_update_grub_command }}"
+
 - name: Restart sysstat
   ansible.builtin.service:
     name: "sysstat"

releasenotes/notes/update_grub-ded0e9404f1f3be4.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    For ``openstack_hosts`` role implemented variable
+    ``openstack_host_custom_grub_options`` which allows to modify ``GRUB_CMDLINE_LINUX_DEFAULT``
+    with arbitrary parameters or remove existing parameters from it.

tasks/configure_metal_hosts.yml

@@ -113,6 +113,11 @@
   with_items: "{{ openstack_kernel_options + openstack_user_kernel_options }}"
   failed_when: false
 
+- name: Configure GRUB
+  ansible.builtin.include_tasks: openstack_grub.yml
+  when:
+    - openstack_host_custom_grub_options | length > 0
+
 - name: Configure sysstat
   ansible.builtin.include_tasks: openstack_sysstat.yml
   when:

tasks/openstack_grub.yml

@@ -0,0 +1,60 @@
+---
+# Copyright 2025, Cleura AB.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+- name: Fetch current GRUB parameters
+  ansible.builtin.shell: . /etc/default/grub && echo ${GRUB_CMDLINE_LINUX_DEFAULT}
+  register: _openstack_grub_default
+  changed_when: false
+
+- name: Update GRUB options
+  ansible.builtin.lineinfile:
+    path: /etc/default/grub
+    regex: '^GRUB_CMDLINE_LINUX_DEFAULT='
+    line: 'GRUB_CMDLINE_LINUX_DEFAULT="{{ _openstack_resulting_grub_record }}"'
+    backup: true
+    mode: '0644'
+    owner: root
+    group: root
+  notify:
+    - Update GRUB
+  vars:
+    # Create list of dicts from the parsed grub parameters, ie:
+    # [{'key': 'console', 'value': 'tty0'}]
+    _openstack_current_grub: >-
+      {{
+        _openstack_grub_default.stdout | split(' ') | map('split', '=') | map('zip', ['key', 'value']) | map('map', 'reverse') | map('community.general.dict')
+      }}
+    # Fetch list of user-provided records which have `state: absent`
+    _openstack_absent_grub_records: >-
+      {{
+        openstack_host_custom_grub_options | selectattr('state', 'defined') | selectattr('state', 'eq', 'absent') | ansible.utils.remove_keys(target='state')
+      }}
+    # Remove records which should be removed from the list
+    _openstack_filtered_custom_grub: >-
+      {{
+        openstack_host_custom_grub_options | selectattr('state', 'defined') | rejectattr('state', 'eq', 'absent') +
+          openstack_host_custom_grub_options | selectattr('state', 'undefined')
+      }}
+    # Combine the result back from dict to GRUB parameters
+    _openstack_resulting_grub_record: |-
+      {% set grub = [] %}
+      {% for record in (_openstack_current_grub + _openstack_filtered_custom_grub) | unique | reject('in', _openstack_absent_grub_records) %}
+      {%   if 'value' in record %}
+      {%     set _ = grub.append(record['key'] ~ '=' ~ record['value']) %}
+      {%   else %}
+      {%     set _ = grub.append(record['key']) %}
+      {%  endif %}
+      {% endfor %}
+      {{ grub | join(' ') }}

vars/debian.yml

@@ -19,6 +19,7 @@ openstack_host_sysstat_file: /etc/default/sysstat
 openstack_host_sysstat_cron_file: /etc/cron.d/sysstat
 openstack_host_cron_template: sysstat.cron.debian.j2
 _openstack_host_initramfs_command: /usr/sbin/update-initramfs -u
+_openstack_host_update_grub_command: grub-mkconfig -o /boot/grub/grub.cfg
 
 ## Kernel modules loaded on hosts
 openstack_host_kernel_modules:

vars/redhat-10.yml

@@ -19,6 +19,7 @@ openstack_host_sysstat_file: /etc/sysconfig/sysstat
 openstack_host_sysstat_cron_file: /etc/cron.d/sysstat
 openstack_host_cron_template: sysstat.cron.redhat.j2
 _openstack_host_initramfs_command: /bin/dracut -f
+_openstack_host_update_grub_command: grub2-mkconfig -o /boot/grub2/grub.cfg
 
 openstack_host_sysstat_cron_mode: "0600"
 

vars/redhat-9.yml

@@ -19,6 +19,7 @@ openstack_host_sysstat_file: /etc/sysconfig/sysstat
 openstack_host_sysstat_cron_file: /etc/cron.d/sysstat
 openstack_host_cron_template: sysstat.cron.redhat.j2
 _openstack_host_initramfs_command: /bin/dracut -f
+_openstack_host_update_grub_command: grub2-mkconfig -o /boot/grub2/grub.cfg
 
 openstack_host_sysstat_cron_mode: "0600"
 

vars/ubuntu.yml

@@ -19,6 +19,7 @@ openstack_host_sysstat_file: /etc/default/sysstat
 openstack_host_sysstat_cron_file: /etc/cron.d/sysstat
 openstack_host_cron_template: sysstat.cron.debian.j2
 _openstack_host_initramfs_command: /usr/sbin/update-initramfs -u
+_openstack_host_update_grub_command: grub-mkconfig -o /boot/grub/grub.cfg
 
 ## Kernel modules loaded on hosts
 openstack_host_kernel_modules: