How to make a custom ISO image

ISO remastering

There are third party scripts to re-build completely custom images, like

• alpine-make-vm-image

(works to only make a disk based VM image)

and there is Alpine's original

• mkimg.

(creates a diskless ISO file - usually what you want for QEMU and Proxmox)

An alternative

It's also possible to commit and load ISO image customizations to and from a writable partition when booting in Diskless Mode.

Booting an ISO image with local customizations

• From a dedicated boot media, obviously.
• Directly_booting_an_ISO_file