When switching between different NixOS configurations (with and
without nullmailer and other services), it can happen that the UID of
the nullmailer user changes. When it happens, the nullmailer service
happily starts, but the user cannot send any email, because the
sendmail wrapper doesn't have permission to write them to the queue.
This commit prevents that. Instead of creating the directories by the
nullmailer user, which doesn't have permissions to change ownership,
we now create them by the systemd-tmpfiles, which has sufficient
permissions to adjust ownership.
markdown can't represent the difference without another extension and
both the html manual and the manpage render them the same, so keeping the
distinction is not very useful on its own. with the distinction removed
we can automatically convert many options that use <code> tags to markdown.
the manpage remains unchanged, html manual does not render
differently (but class names on code tags do change from "code" to "literal").
the conversion procedure is simple:
- find all things that look like options, ie calls to either `mkOption`
or `lib.mkOption` that take an attrset. remember the attrset as the
option
- for all options, find a `description` attribute who's value is not a
call to `mdDoc` or `lib.mdDoc`
- textually convert the entire value of the attribute to MD with a few
simple regexes (the set from mdize-module.sh)
- if the change produced a change in the manual output, discard
- if the change kept the manual unchanged, add some text to the
description to make sure we've actually found an option. if the
manual changes this time, keep the converted description
this procedure converts 80% of nixos options to markdown. around 2000
options remain to be inspected, but most of those fail the "does not
change the manual output check": currently the MD conversion process
does not faithfully convert docbook tags like <code> and <package>, so
any option using such tags will not be converted at all.
Nullmailer expects that this directory exists (see
073f4e9c5d/doc/nullmailer-send.8 (L185)).
When it doesn't and an email cannot be sent due to a permanent failure
or has been in the queue longer than queuelifetime (7 days), message
"Can't rename file: No such file or directory" starts appearing in the
log and nullmailer never sends "Could not send message" notification.
This means that the user may never learn that his email was not
delivered.
The current `remotes` option is a string option containing nullmailer remote
definitions. However, those definitions may contain secret credentials and
should therefore not be put world-readable in the nix store.
I added a `remotesFile` option, which allows to specify a path to the remotes
definition file instead. This way, the definitions can be kept outside of the
nix store with more secure file permissions.