ISO Image

There were a few tools that allowed for this in the past.

Does it have to be based on Ubuntu?

Any more detail on why it has to be Ubuntu than"yes'"?

There are other distros which are better suited to solving this particular need.

You will get better answers if you expand on why you would want to do this. It is quite likely that creating an ISO image is not the correct solution to the problem you're actually trying to address

If what the OP is trying to do is configure the system how they want it, and then be able to duplicate it later, perhaps this is what they need: https://kernelpanic.life/software/cloning-a-system-with-ansible.html

Making a CD/DVD of your install is not going to help you because in a few months time when you go to do a reinstall, it's going to be out of date, so the first thing you will have to do is a distribution upgrade.

What you could do is put /home in a separate partition and /opt in a separate partition. Install virtual box and other larger applications to /opt and when you do a reinstall install the OS to /, but retain your existing /home and /opt.

Personally I just periodically do a clear out of clutter and then do a dist-upgrade.

If you are worried about viruses, run ClamAV.

I'm sorry to say this but the level of knowledge you seem to have means you're most likely not going to be up to the task. I dont mean that in a bad way at all just saying it the way I see it trying to save you from a whole lot of frustration and disappointment. Also the reasons why you want your own ISO arent really valid reasons. For starters whats that password thing you're on about? Thats just crazy talk. Same with the reinstall every two months because of 'clusters' (what are they btw?) and viruses. Sorry I dont mean to be mean I just dont think you know what you're at really.

@CalamariFritti I think the OP means clutter, not clusters.

I can think of some instances where you (well, I) might want to have an image of a 'pristine' system with all the required software installed and any unnecessary bloat/clutter etc removed. However those instances would be very particular and nothing like what the OP thinks he requires.

I run Ubuntu on my laptop which is more than 5 years old. I upgraded the OS once, apply updates when they come out and declutter occasionally. I don't run an anti-virus program but probably should run a scan every now and then. However I don't visit dodgy websites, open dodgy links in emails or stick in unknown usb sticks so I reckon I'm safe enough. I'm not going to admit how often I've changed my password 🤔 but to do it every couple of months is a bit much IMO unless forced to by your employer. If the data is that important, it should be encrypted.

The OP seems to be putting themselves through a lot of hardship for no good reason, or at least none that they've revealed here

I think clonezilla is what you want

Depends how you have deleted the things.

I don't know what desktop environment you are using, but most have a recycle bin type feature. You can empty that before the cloning. If you use the rm command, there's no safety net. So no, you won't copy the deleted stuff.

This may/not work with Ubuntu, would be worth testing though

https://github.com/bergmann-max/debain-preseed-iso-generator

You didn't miss it, the OP added this as new information later in the thread. I was going to point it out but then couldn't be arsed😴

If someone has physical access to your computer, you have to consider it compromised. Unless the disks are encrypted and it was already powered off - disk encryption keys have been recovered from memory or the TPM on powered on computers.