Refactor 03-reset-bls-entries into an element

This script is common across centos and rhel, so should really be in its
own element.

Change-Id: If8cbb38bd739169afcbe8e99325249f86f453bc5
Signed-off-by: Steve Baker <sbaker@redhat.com>
Assisted-By: Opencode - Claude Sonnet 4.6

diskimage_builder/elements/centos/element-deps

@@ -1,5 +1,6 @@
 cache-url
 redhat-common
+redhat-reset-bls-entries
 rpm-distro
 source-repositories
 systemd-machine-id

diskimage_builder/elements/redhat-reset-bls-entries/README.rst

@@ -0,0 +1,22 @@
+========================
+redhat-reset-bls-entries
+========================
+
+Renames Boot Loader Specification (BLS) entries in
+``/boot/loader/entries/`` to use the machine-id set during the build,
+as a workaround for https://bugzilla.redhat.com/show_bug.cgi?id=2032680.
+
+Upstream qcow2 images for CentOS 9-stream and RHEL 9 ship with
+pre-existing BLS entries named after the image's original machine-id.
+When diskimage-builder sets a new machine-id via ``systemd-machine-id-setup``
+(see the ``systemd-machine-id`` element), these entries are stale and
+``grub2-mkconfig`` will not update them correctly.  This element renames
+each ``*.conf`` entry under ``/boot/loader/entries/`` to match the
+build-time machine-id so that subsequent bootloader configuration steps
+work as expected.
+
+This element is a no-op on releases other than ``9-stream`` (CentOS)
+and ``9`` (RHEL).
+
+This element is pulled in automatically by the ``centos`` and ``rhel``
+elements.

diskimage_builder/elements/redhat-reset-bls-entries/post-install.d/03-reset-bls-entries

@@ -6,7 +6,9 @@ fi
 set -eu
 set -o pipefail
 
-if [[ ! '9-stream' =~ ${DIB_RELEASE} ]]; then
+# This workaround is only needed for releases that ship a qcow2 image
+# with pre-existing BLS entries: centos 9-stream and rhel 9.
+if [[ ! ${DIB_RELEASE} =~ ^(9-stream|9)$ ]]; then
     exit 0
 fi
 

diskimage_builder/elements/rhel/element-deps

@@ -1,5 +1,6 @@
 cache-url
 redhat-common
+redhat-reset-bls-entries
 rhel-common
 rpm-distro
 source-repositories

diskimage_builder/elements/rhel/post-install.d/03-reset-bls-entries

@@ -1,34 +0,0 @@
-#!/bin/bash
-
-if [ ${DIB_DEBUG_TRACE:-0} -gt 0 ]; then
-    set -x
-fi
-set -eu
-set -o pipefail
-
-if [[ ! '9' =~ ${DIB_RELEASE} ]]; then
-    exit 0
-fi
-
-# This is a workaround for the grub issue reported upstream with
-#  https://bugzilla.redhat.com/show_bug.cgi?id=2032680
-
-# This renames the BLS entries from the upstream .qcow2 image in
-# /boot/loader/entries with the current machine-id. This means that in the
-# bootloader setup, grub2-mkconfig will update config options as required.
-
-pushd /boot/loader/entries
-
-machine_id=$(</etc/machine-id)
-
-for entry in *.conf; do
-    new_entry=$(echo $entry | sed "s/^[a-f0-9]*/$machine_id/")
-    echo "renaming $entry to $new_entry for new machine-id"
-    if [[ $entry != $new_entry ]]; then
-        mv $entry $new_entry
-    fi
-done
-popd
-
-echo "--- Show kernels ---"
-grubby --info=ALL