fix: fix centos / rhel family 8+ grub-bios boot

Signed-off-by: Adphi <philippe.adrien.nousse@gmail.com>

grub_common.go

@@ -32,6 +32,8 @@ GRUB_TIMEOUT=0
 GRUB_CMDLINE_LINUX_DEFAULT="%s"
 GRUB_CMDLINE_LINUX=""
 GRUB_TERMINAL=console
+GRUB_DISABLE_OS_PROBER=true
+GRUB_ENABLE_BLSCFG=false
 `
 
 type grubCommon struct {
@@ -44,7 +46,7 @@ type grubCommon struct {
 
 func newGrubCommon(c Config, r OSRelease) *grubCommon {
 	name := "grub"
-	if r.ID == "centos" {
+	if r.ID == ReleaseCentOS || r.ID == ReleaseAlmaLinux || r.ID == ReleaseRocky {
 		name = "grub2"
 	}
 	return &grubCommon{

templates/centos.Dockerfile

@@ -36,7 +36,24 @@ RUN dracut --no-hostonly --regenerate-all --force
 
 {{ if .Password }}RUN echo "root:{{ .Password }}" | chpasswd {{ end }}
 
-{{- if not .Grub }}
+{{- if .Grub }}
+RUN set -e; \
+    for linux in /usr/lib/modules/*/vmlinuz; do \
+      [ -e "$linux" ] || continue; \
+      kver="$(basename "$(dirname "$linux")")"; \
+      cp "/usr/lib/modules/${kver}/vmlinuz" "/boot/vmlinuz-${kver}"; \
+    done
+RUN set -e; \
+    for linux in /boot/*/*/linux; do \
+      [ -e "$linux" ] || continue; \
+      dir="$(dirname "$linux")"; \
+      kver="$(basename "$dir")"; \
+      initrd="${dir}/initrd"; \
+      [ -e "$initrd" ] || continue; \
+      ln -sf "${linux#/boot/}" "/boot/vmlinuz-${kver}"; \
+      ln -sf "${initrd#/boot/}" "/boot/initramfs-${kver}.img"; \
+    done
+{{- else }}
 RUN cd /boot && \
       mv $(find / -name 'vmlinuz*') /boot/vmlinuz && \
       mv $(find . -name 'initramfs-*.img' -o -name initrd) /boot/initrd.img