create custom ISO in Ubuntu Server 21.04 for unattended and offline installation

Question

I need to create a .ISO with the cloud-init folder inside that would hold the autoinstall-user-data and meta-data files and edit the grub file to use it

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=21.04
DISTRIB_CODENAME=hirsute
DISTRIB_DESCRIPTION="Ubuntu 21.04"

in the base .ISO for this release there isn´t (I don`t know if for a good reason?), the isolinux folder and files so if I follow the tipical procedure at the end I can´t create custom .ISO with genisoimage or similar software as I will be missing all that important part in isolinux, for example the isolinux/txt.cfg referenced in all the manuals for ubuntu server 20.4 to do this task.

any ideas on how to create custom .ISOs for this latest release that will use the autoinstall-user-data for an unattended installation in a server ?

Regards

Answer 1

One of the subiquity developers published a project to customize the live-server ISO.

• announcement discourse thread
• mwhudson project home page

Before that, a community member had also created a project to customize the installer ISO specifically to embed autoinstall files.

• covertsh project home page

I have not tried either of these solutions myself.

Answer 2

What I did was copy the isolinux directory from the Ubuntu 20 server ISO image, make my updates, and create my custom ISO image. It works for me, but I was wondering if there is a reason why the isolinux directory was missing, and if there is another preferred method for creating custom Ubuntu images on an Ubuntu version greater than 20.