Making multiple mirrors seems like the best solution. I will explore that route.
I was hoping there was something built into APT or unattended-upgrades, I vaguely remembered such a feature... what I was remembering was probably Phased Updates, but those are controlled by Ubuntu not by me, and roll out too fast.
I am not worried about upgrades so bad that they literally don't boot. I am worried about all the possible problems that might break my service.
Go away. You're here pretending that Ubuntu only does security updates. You have never received a bugfix from Ubuntu? And I am the one who doesn't know what he's talking about?
Why do you insert yourself into conversations with other people? I am the one who's rude?
Which distro is image based and have the staggered rollout feature I'm after?
I find it hard to stay courteous in the presence of people like you, who reply without reading my post, call me "duder" and say I "don't understand what I am asking for".
Thankfully, I did get a great answer from someone else.
Minimizing risk is LITERALLY what I asked for. You clearly don't understand what I asked for.
I think I would want a bigger delay, an faulty upgrade might only break something within hours.
Ubuntu only does security updates, no?
No, why do you think that?
run your own package mirror
I think you might be on to something here. I could probably do this with a package mirror, updating it daily and rotating the staging, production, etc URLs to serve content as old as I want. This would require a bit of scripting but seems very configurable.
Thanks for the idea! Can't believe I didn't think of that. It seems so obvious now, I wonder if someone already made it.
I found the page about "phased upgrades" (somehow missed it searching for "staggered", "incremental", "delayed", etc). Thanks for the pointer!
Unfortunately it doesn't seem configurable on my end, and it rolls out in about 54 hours so it can take out most of my machines before I have time to react (my first machine might update ~20h into the phased rollout, the rest will break within 24h). Bummer!
~~(oops - replied in the wrong place)~~
So you can test the updates before fixing production.
My question is how to do that with APT.
I can roll back with APT too, my question is how to do the staggered rollout.