Add or changing content in the bootc image initramfs

The rhel10/rhel-bootc image uses the dracut infrastructure to build an initial RAM disk (initrd) during the image build time. A default initrd is built and included in the /usr/lib/modules/<kernel_version>/initramfs.img location inside the container image.

Before you begin

  • A booted system using bootc.

About this task

You can use a drop-in configuration file to extend the dracut configuration, and place it in a file in the /usr/lib/dracut/dracut.conf.d/ directory. This re-creates `initrd with the modules you want to add.

Procedure

Re-create the initrd as part of a container build: 
FROM <baseimage>
COPY <custom_modules_list>.conf /usr/lib/dracut/dracut.conf.d
RUN set -x; kver=$(cd /usr/lib/modules && echo *); dracut -vf /usr/lib/modules/$kver/initramfs.img $kver
Note

By default the dracut command attempts to pull the running kernel version, which causes an error. Explicitly pass to dracut the kernel version of the target to avoid errors.