Can I install a new kernel package using `yum` without updating grub.cfg?

Question

I have 49 rpm packages that I need to install from a local directory. One of which is kernel-4.9.135 Therefore, I want to use yum so all dependencies are managed for me (instead of passing rpm a list of rpm files).

I also have a very customized grub.cfg file that I do not want touched during this process.

I examined the scripts that are run when the kernel package is installed:

# rpm -qp --scripts ./kernel-4.9.135-1.x86_64.rpm 
postinstall scriptlet (using /bin/sh):
if [ -x /sbin/installkernel -a -r /boot/vmlinuz-4.9.135 -a -r /boot/System.map-4.9.135 ]; then
cp /boot/vmlinuz-4.9.135 /boot/.vmlinuz-4.9.135-rpm
cp /boot/System.map-4.9.135 /boot/.System.map-4.9.135-rpm
rm -f /boot/vmlinuz-4.9.135 /boot/System.map-4.9.135
/sbin/installkernel 4.9.135 /boot/.vmlinuz-4.9.135-rpm /boot/.System.map-4.9.135-rpm
rm -f /boot/.vmlinuz-4.9.135-rpm /boot/.System.map-4.9.135-rpm
fi
...

installkernel contains the following:

if [ -n "$cfgLoader" ] && [ -x /sbin/new-kernel-pkg ]; then
if [ -n "$(which dracut 2>/dev/null)" ]; then
    new-kernel-pkg --mkinitrd --dracut --host-only --depmod --install --kernel-name $KERNEL_NAME $KERNEL_VERSION
else
    new-kernel-pkg --mkinitrd --depmod --install --kernel-name $KERNEL_NAME $KERNEL_VERSION
fi
new-kernel-pkg --rpmposttrans --kernel-name $KERNEL_NAME $KERNEL_VERSION
fi

And new-kernel-pkg uses grubby to update my grub.cfg file.

Is there some way to tell yum, and therefore the kernel rpm, to not do anything to alter grub.cfg, while using yum install to install all of my packages in one fell swoop?

The workaround is to copy my currentgrub.cfg to the side and copy it back after yum is finished but I thought I'd ask the question nonetheless.

Answer 1

Your trick with grub.conf is working solution. Also you can apply one of the next approaches:

1. Download kernel rpm package with yumdownloader and install kernel package with --noscripts parameter to ignore scripts which configure package by running prerun, postrun ... scripts during package are being configured. There is no way to tell --noscripts to yum directly.
2. If you want persistent grub.conf after any new kernel installation via yum you should copy your current grub.conf menu entries that belong to your kernel to /etc/grub.d/40_custom and unset exec permissions (chmod a-x) from /etc/grub.d/30_probe_os (this script scans /boot directory for new kernels and initramfs files and generates menuentries for grub.conf). After this step all attempts of generate grub.conf bu running grub2-mkconfig will return only menu entries that contains in your custom configuration file /etc/grub.d/40_custom.