Major changes
- Port to systemd timers: for each archive configuration is created a
tarsnap@archive-name.timer which triggers the instanced service unit
- Rename the `config` option to `archives`
Minor/superficial improvements
- Restrict tarsnap service capabilities
- Use dirOf builtin
- Set executable bit for owner of tarsnap cache directory
- Set IOSchedulingClass to idle
- Humanize numbers when printing stats
- Rewrite most option descriptions
- Simplify assertion
The Tarsnap module is now far more flexible, allowing individual
archives with individual options to be specified at will, allowing
granular backup schedules, etc.
Signed-off-by: Austin Seipp <aseipp@pobox.com>
Using pkgs.lib on the spine of module evaluation is problematic
because the pkgs argument depends on the result of module
evaluation. To prevent an infinite recursion, pkgs and some of the
modules are evaluated twice, which is inefficient. Using ‘with lib’
prevents this problem.
