Previously, some files were copied into the Nixpkgs tree, which meant
we wouldn't easily be able to update them, and was also just messy.
The reason it was done that way before was so that a few NixOS
options could be substituted in. Some problems with doing it this way
were that the _package_ changed depending on the values of the
settings, which is pretty strange, and also that it only allowed those
few settings to be set.
In the new model, mailman-web is a usable package without needing to
override, and I've implemented the NixOS options in a much more
flexible way. NixOS' mailman-web config file first reads the
mailman-web settings to use as defaults, but then it loads another
configuration file generated from the new services.mailman.webSettings
option, so _any_ mailman-web Django setting can be customised by the
user, rather than just the three that were supported before. I've
kept the old options, but there might not really be any good reason to
keep them.
We already had python3Packages.mailman, but that's only really usable
as a library. The only other option was to create a whole Python
environment, which was undesirable to install as a system-wide
package.
This replaces all Mailman secrets with ones that are generated the
first time the service is run. This replaces the hyperkittyApiKey
option, which would lead to a secret in the world-readable store.
Even worse were the secrets hard-coded into mailman-web, which are not
just world-readable, but identical for all users!
services.mailman.hyperkittyApiKey has been removed, and so can no
longer be used to determine whether to enable Hyperkitty. In its
place, there is a new option, services.mailman.hyperkitty.enable. For
consistency, services.mailman.hyperkittyBaseUrl has been renamed to
services.mailman.hyperkitty.baseUrl.
Using a custom path in the Nix store meant that users of the module
couldn't add their own config files, which is a desirable feature. I
don't think avoiding /etc buys us anything.
Hasn't been updated since 2017 and breaks when building with a more
recent gcc (gcc5 needs to be removed as it breaks with glibc 2.30). I
tried to update this to a more recent version which didn't work either,
but as this is pretty old I'm not even sure if this package is used atm.
