Issue: after installing, running `yubikey-agent -setup` produces the
following error:
```
nixOS: Failed to connect to the YubiKey: connecting to pscs: the Smart
card resource manager is not running
```
More on this issue: https://github.com/FiloSottile/yubikey-agent/issues/137
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.
This adds a `wantedBy` clause to the user systemd service for
yubikey-agent, to ensure an enabled agent is started on boot. This
brings the behavior inline with existing documentation.
If the user has selected a graphical pinentry program, then we need to
wait for the graphical environment to exist before starting the
yubikey-agent. I've found that if we start the agent earlier it will
fail when we perform an ssh command later.
This adds yubikey-agent as a package and a nixos module.
On macOS, we use `wrapProgram` to set pinentry_mac as default in PATH;
on Linux we rely on the user to set their preferred pinentry in PATH.
In particular, we use a systemd override to prefix PATH to select a
chosen pinentry program if specified.
On Linux, we need libnotify to provide the notify-send utility for
desktop notifications (such as "Waiting for Yubikey touch...").
This might work on other flavors of unix, but I haven't tested.
We reuse the programs.gnupg.agent.pinentryFlavor option for
yubikey-agent, but in doing so I hit a problem: pinentryFlavour's
default value is specified in a mkDefault, but only conditionally. We
ought to be able to pick up the pinentryFlavour whether or not gpg-agent
is running. As a result, this commit moves the default value to the
definition of programs.gnupg.agent.enable.
