tvl-depot/users/wpcarro/website/blog/posts/auto-reboot-nixos.md
William Carroll e1833e95f2 feat(wpcarro/blog): Create short post about scheduled reboots
Slowly building the habit of blogging more (especially about nix).

Change-Id: I13006a6555d746ab55b4b282ea83bc732573a58e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5149
Tested-by: BuildkiteCI
Reviewed-by: wpcarro <wpcarro@gmail.com>
Autosubmit: wpcarro <wpcarro@gmail.com>
2022-01-31 22:34:32 +00:00

40 lines
1.1 KiB
Markdown

## Show me the codes
Regularly rebooting machines can be a useful, hygienic practice, but quite
frankly I cannot be relied on to remember to regularly reboot my machine.
Let's free-up some wetware-RAM by automating this with Nix. The following
addition to your `configuration.nix` will schedule daily reboots at `03:00`:
```nix
systemd.timers.auto-reboot = {
wantedBy = [ "timers.target" ];
timerConfig = {
OnCalendar = "*-*-* 03:00:00";
Unit = "reboot.target";
};
};
```
If you want to fiddle with the date format, `systemd-analyze` is your friend:
```shell
λ systemd-analyze calendar '*-*-* 03:00:00'
Normalized form: *-*-* 03:00:00
Next elapse: Tue 2022-02-01 03:00:00 PST
(in UTC): Tue 2022-02-01 11:00:00 UTC
From now: 12h left
```
After calling `nixos-rebuild switch`, you can verify that `systemd` started the
timer with:
```shell
λ systemctl list-timers auto-reboot
# output omitted because I'm writing this from a different machine
```
## That's all, folks!
I wanted to keep this post short-and-sweet, to build the habit of posting more
regularly. Hopefully someone out there found this useful.