nixos/pgbouncer: rework RFC42 integration

Commit bfb9d1825d545d96278db84d43e0b2a529775089 added RFC42 support
which is a good thing in general, but this implementation has the
following flaws:

* `services.pgbouncer.logFile` was not renamed to `[...].log_file`, but
  to `[...].logfile`. Also the use of `mkRenamedOptionModule` is
  inappropriate here because the two options are not equivalent: the old
  option took a path relative to the home directory, the new an absolute
  path.

* Using `mkRenamedOptionModule` with options that don't exist (but are
  keys in a freeform attr-set or an `attrsOf X`), you get the following
  error when referencing an option you didn't declare:

    error: evaluation aborted with the following error message: 'Renaming error: option `services.pgbouncer.settings.pgbouncer.listen_port' does not exist.'

  This error is pretty bad because it's not actionable for an end-user of
  the module. A possible use-case is doing

    networking.firewall.allowedTCPPorts = [ config.services.pgbouncer.listenPort ];

  without specifying a custom listen port. This is an example of why you
  want to keep options, they already contain defaults and you can re-use
  those defaults in other parts of your system configuration.

  I decided to re-add a bunch of options where I figured that it's
  either useful to be able to address those in the NixOS configuration
  or having documentation directly in the options' reference in the
  NixOS manual.

  I didn't add all options, I'll leave that to the maintainers of
  pgbouncer.

0 files changed, 0 insertions, 0 deletions