DRAFT: check headers for firmware version

[T0biii]

early draft for ngnix totaly untested (just ideas how to use the user agent and the firmware header)

https://gluon.readthedocs.io/en/v2023.2.x/releases/v2023.2.html#important-notes
Upgrades to gluon v2023.2 and later releases are only supported from releases gluon v2022.1 and later

FFMUC (from map):

• v2024.4.2-next (gluon-v2023.2.2)
• v2024.3.2-next (gluon-v2023.2.2)

https://gluon.readthedocs.io/en/v2023.1.x/releases/v2023.1.html#important-notes
Upgrades to gluon v2023.1 and later releases are only supported from releases gluon v2021.1 and later.

FFMUC (from map):

• v2024.1.1 - v2024.4.2 (gluon-v2023.1.2)

the firmware Version header is set to: /lib/gluon/release

grische:

Falls Firmware ohne X-Firmware kommt, dann redirect auf legacy-v2022.5.x
Falls Firmware X-Firmware <v2022.5.8 kommt, dann redirecte auf legacy-v2022.5.x
Falls Firmware X-Firmware =>v2022.5.8 und <2024.8.1 kommt, dann redirecte auf legacy-v2024.7.x
Falls Firmware >=v2024.8.1 kommt, dann redirecte auf stable

[T0biii]

the map function seems to work fine

but nested ifs seems to be a problem, maybe we need another map that checks the Version with Regex and based on this return the right firmware

https://web.archive.org/web/20240215023942/https://www.nginx.com/resources/wiki/start/topics/depth/ifisevil/
https://ezecodes.wordpress.com/2016/06/30/multiple-if-conditions-in-nginx/

set $UD "";
   if ($arg_user){
      set $UD T;
   }
   if ($request_method = 'GET'){
      set $UD "${UD}G";
   }
   if ($UD = TG){
   }

[DasSkelett]

I think I got it to work as follows, using another map.
It is not the most elegant solution, you have to do a bunch of regexes to approach the target version step by step (you could condense the regexes per target version to a single one, but I went for the slightly more readable approach and spread it over multiple lines).
Note that as is configured right now, for example a router with firmware v2022.5.6 would first upgrade to v2022.5.8, before going to the next major one - but I believe this is what we want anyway, so we can apply any "pre-migration" fixes.

Also the actual versions are placeholders right now, I don't know whether we actually need the step with v2024.6.1 already? The v2024.7.1 originally mentioned in the PR description doesn't exist.

Testing commands

curl --user-agent "Gluon Autoupdater (using libuclient)" -H "X-FIRMWARE-VERSION: v2018.2.1" -vL http://localhost/stable/manifest
curl --user-agent "Gluon Autoupdater (using libuclient)" -H "X-FIRMWARE-VERSION: v2022.5.7" -vL http://localhost/stable/manifest
curl --user-agent "Gluon Autoupdater (using libuclient)" -H "X-FIRMWARE-VERSION: v2022.5.8" -vL http://localhost/stable/manifest
curl --user-agent "Gluon Autoupdater (using libuclient)" -H "X-FIRMWARE-VERSION: v2023.8.1" -vL http://localhost/stable/manifest
curl --user-agent "Gluon Autoupdater (using libuclient)" -H "X-FIRMWARE-VERSION: v2024.2.1" -vL http://localhost/stable/manifest
curl --user-agent "Gluon Autoupdater (using libuclient)" -H "X-FIRMWARE-VERSION: v2024.6.1" -vL http://localhost/stable/manifest
curl --user-agent "Gluon Autoupdater (using libuclient)" -H "X-FIRMWARE-VERSION: v2024.9.1" -vL http://localhost/stable/manifest
curl --user-agent "Gluon Autoupdater (using libuclient)" -vL http://localhost/stable/manifest
curl -vL http://localhost/stable/manifest

[grische]

I would not use our internal versions as this would require us to update this file every time we do a new firmware release