Fix issue with GRUB defaulting to an old kernel

etc/kayobe/ansible/reset-bls-entries.yml

@@ -0,0 +1,39 @@
+---
+# Custom playbook to reset Boot Loader Specification (BLS) entries to resolve
+# an issue with GRUB defaulting to an old kernel. This is adapted from a Bash
+# script in diskimage-builder:
+# https://opendev.org/openstack/diskimage-builder/src/branch/master/diskimage_builder/elements/rhel/post-install.d/03-reset-bls-entries
+
+- name: Reset BLS entries
+  hosts: overcloud
+  become: true
+  tags:
+    - reset-bls-entries
+  tasks:
+    - name: Get machine ID
+      command: cat /etc/machine-id
+      register: machine_id
+      check_mode: false
+
+    - name: Find entries with wrong machine ID
+      ansible.builtin.find:
+        paths: /boot/loader/entries
+        patterns: "*.conf"
+      register: bls_entries
+      check_mode: false
+
+    # We set force to false to avoid replacing an existing BLS entry with the
+    # correct machine ID.
+    - name: Rename entries with wrong machine ID
+      copy:
+        src: "/boot/loader/entries/{{ item }}"
+        dest: "/boot/loader/entries/{{ item | ansible.builtin.regex_replace('^[a-f0-9]*', machine_id.stdout) }}"
+        force: false
+        remote_src: true
+      with_items: "{{ bls_entries.files | map(attribute='path') | reject('search', machine_id.stdout) | map('basename') }}"
+
+    - name: Remove entries with wrong machine ID
+      file:
+        path: "/boot/loader/entries/{{ item }}"
+        state: absent
+      with_items: "{{ bls_entries.files | map(attribute='path') | reject('search', machine_id.stdout) | map('basename') }}"

releasenotes/notes/reset-bls-entries-b2bded62c5887937.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    Add a new ``reset-bls-entries.yml`` custom playbook which will rename
+    existing Boot Loader Specification (BLS) entries using the current machine
+    ID for each host. This should fix an issue with Grub not selecting the most
+    recent kernel during boot.