centos grub2-install no longer supports EFI

[Konrad Gube]

The version of grub2-install included in the latest centos cloud image (CentOS-8-GenericCloud-8.4.2105-20210603.0.x86_64.qcow2) contains a patch to disable installation on EFI systems:
https://src.fedoraproject.org/rpms/grub2/blob/rawhide/f/0166-grub-install-disable-support-for-EFI-platforms.patch#_43

It will now fail with:
/usr/sbin/grub2-install: error: this utility cannot be used for EFI platforms because it does not support UEFI Secure Boot.

The reasoning behind the change is explained in the patch.

A comment on this fedora bug report mentions that even `grub2-install --target=i386-pc` may fail, if run on an EFI system: https://bugzilla.redhat.com/show_bug.cgi?id=1917213#c33
I haven't tested this, though.

[Konrad Gube (kgube)]

Okay, I just noticed that I was using an older version (3.7) of diskimage-builder.

Using 3.11, the grub2 installation on centos8 works fine, so this bug can be closed, I guess.

[Cristian Le (lecris)]

I think this issue should be revived. If we build the latest centos 9 this issue occurs again when deploying ironic with the created baremetal image