Upgrade all systems to Stretch
I'll probably use sib as a dev/testing platform for this project, at least for the services it runs.
In theory this effort can very well be spread from now to ~2019 or even 2020, and we may decide to stick to Jessie LTS on some systems (if that's an option with Puppet 4), but we have plenty of good reasons to want to run current Debian on most of our systems.
Left to do:
- buse: should be straightforward, modulo MySQL → MariaDB
ecours: should be straightforward, modulo MySQL → MariaDB lizard: should be straightforward isobuilderN.lizard: should be trivial, tracked on #11006 isotesterN.lizard
- whisperback.lizard: it seems that Postfix multi-instances support has changed a bit on Stretch