Fix BLS entries for /boot partitions

Creating a separate /boot partition is desirable in some cases[1].
This change detects if /boot is a partition, and ensures that the
kernel/ramdisk paths are correct in either case. This is applied to
all BLS entries files, whether they were generated by the previous
grub2-mkconfig call or in the source image.

This means the rhel9 specific workaround can be removed since all
paths are now normalised at this stage.

[1] https://review.opendev.org/c/openstack/tripleo-image-elements/+/846807

Change-Id: I62120ec8c65876e451532d2654d37435eb3606a6
Resolves: rhbz#2101514

diskimage_builder/elements/bootloader/finalise.d/50-bootloader

@@ -156,6 +156,29 @@ if [[ ${DIB_BLOCK_DEVICE} == "efi" ]]; then
     fi
 fi
 
+# Ensure paths in BLS entries account for /boot being a partition or part of the
+# root partition
+if [[ -e /boot/loader/entries ]]; then
+    pushd /boot/loader/entries
+    set +e
+    mountpoint /boot
+    bootmount=$?
+
+    for entry in *; do
+        if [[ $bootmount -eq 0 ]]; then
+            sed -i "s| /boot/vmlinuz| /vmlinuz|" $entry
+            sed -i "s| /boot/initramfs| /initramfs|" $entry
+        else
+            sed -i "s| /vmlinuz| /boot/vmlinuz|" $entry
+            sed -i "s| /initramfs| /boot/initramfs|" $entry
+        fi
+    done
+    set -e
+    popd
+    # Print resulting grubby output for debug purposes
+    grubby --info=ALL
+fi
+
 if [[ ! "$ARCH" =~ "ppc" ]] && [[ -z  "${DIB_BLOCK_DEVICE}" ]]; then
     echo "WARNING: No bootloader installation will occur."
     echo "To install a bootloader ensure you have included a block-device-* element"

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

@@ -27,11 +27,6 @@ for entry in *.conf; do
     if [[ $entry != $new_entry ]]; then
         mv $entry $new_entry
     fi
-
-    # RHEL-9 is unique in having a separate /boot partition, fix the paths to assume
-    # /boot will be in the root partition.
-    sed -i "s| /vmlinuz| /boot/vmlinuz|" $new_entry
-    sed -i "s| /initramfs| /boot/initramfs|" $new_entry
 done
 popd