How to make a custom ISO image

One way to completely re-build custom images is to use a script like alpine-make-vm-image.

• If you want to make a customized installer, you need to create .default_boot_services which will cause mkinitfs to create the defaults for the live image.

An alternative

Commiting and loading ISO image customizations

Booting an ISO image with local customizations

• From dedicated boot media, obviously.
• (Example included:) Booting and customizing an ISO image with an .apkovl in a Qemu virtual machine.
• Using e.g. Debian's grub-imageboot package and booting .iso files directly, instead of partitions.