Change OS Detection in debug script

[PromoFaux]

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What does this PR aim to accomplish?:

Currently the supported/unsupported OS detection is based on the distro name being one of 5 set values, this is fine, but then we also need to check further. For example Raspbian <9 is not supported.

This PR adds that check. I'd like to get a similar output into the installer if it fails, however I am starting to think that maybe the installer should prompt user to run and read the debug log if an update fails. Though obviously that won't necessarily work on a fresh install.

Examples using a Debian 10 (Buster) system:
supportedos.txt contains:

Raspbian=9,10
Ubuntu=16,18
Debian=9,10
Fedora=31,32
CentOS=7,8

Debug output:

supportedos.txt contains:

Raspbian=9,10
Ubuntu=16,18
Debian=9
Fedora=31,32
CentOS=7,8

Debug Output:

supportedos.txt contains:

Raspbian=9,10
Ubuntu=16,18
Fedora=31,32
CentOS=7,8

Debug Output:

[yubiuser]

From you example

Debian=9
Distro is supported but version is not - please upgrade

Wording doesn't make sense if version > supported version

[PromoFaux]

Debian=9

The intention of this is not to say "Version 9 and up are supported", but rather "only version 9 is supported", hence it fails the check when the detected version is 10

Obviously in real life we support Debian 10, but this is just an demonstration of what the output would look like if the detected version is not listed.

edit: Never mind, I think I misunderstood what you wrote :)

double-edit: I've updated the screenshots on the OP

[yubiuser]

Better but not perfect ;-)
You could check if ${os_version} is bigger or smaller than the biggest/smallest supported version and change the error accordingly (not yet supported/not supported - please upgrade)

[PromoFaux]

That's not too bad an idea. I'll have a think on it later

[PromoFaux]

I may change up some of the logic in this PR, actually, based on #3441

[pralor-bot]

This pull request has been mentioned on Pi-hole Userspace. There might be relevant details there:

https://discourse.pi-hole.net/t/pi-hole-5-1-released/35577/1