"Deploying" images rather than installing from the official ISO?
I like my Linux installs heavily customized and security hardened, to the extent that copying over /home won't cut it, but not so much that it breaks when updating Debian. Whenever someone mentions reinstalling Linux, I am instinctively nervous thinking about the work it would take for me to get from a vanilla install to my current configuration.
It started a couple of years ago, when dreading the work of configuring Debian to my taste on a new laptop, I decided to instead just shrink my existing install to match the new laptop's drive and dd it over. I later made a VM from my install, stripped out personal files and obvious junk, and condensed it to a 30 GB raw disk image, which I then deployed on the rest of my machines.
That was still a bit too janky, so once my configuration and installed packages stabilized, I bit the bullet, spun up a new VM, and painstakingly replicated my configuration from a fresh copy of Debian. I finished with a 24 GB raw disk image, which I can now deploy as a "fresh" yet pre-configured install, whether to prepare new machines, make new VMs, fix broken installs, or just because I want to.
All that needs to be done after dd'ing the image to a new disk is:
Some machines: boot grubx64.efi/shimx64.efi from Ventoy and "bless" the new install with grub-install and update-grub
Reencrypt LUKS root partition with new password
Configure user and GRUB passwords
Set hostname
Install updates and drivers as needed
Configure for high DPI if needed
I'm interested to hear if any of you have a similar workflow or any feedback on mine.
I have the exact same workflow except I have two images: one for legacy/MBR and another for EFI/GPT -- once I read your post I was glad to see I'm not alone haha!