smartctl_exporter already runs with SupplementaryGroups "disk", which
gives full access to SATA drives, but NVMe devices are owned by
root:root, resulting in no access:
[...] msg="Smartctl open device: /dev/nvme0 failed: Permission denied"
This patch introduces a "smartctl-exporter-access" supplementary
group, and an udev rule with setfacl to give the exporter access to NVMe
drives, without changing the base root:root ownership.
Fixes https://github.com/NixOS/nixpkgs/issues/210041
Only restart `systemd-udevd.service` if udev rules in `/etc/udev/rules`
actually changed. The paths of `services.udev.packages` may change
frequently but the resulting udev rules built by `udevRulesFor`
likely change less often.
This has the added benefit of not adding `services.udev.packages` to
the system closure if they are only used for their udev rules
(issue #308937).
Follow up to #342584.
Similarly to that PR, it is surprising that software which was installed by the user isn't available to a script run over ssm by default.
When executing commands with ssm, users will now have more predictable access to baked-in software instead of an extremely bare-minimum set currently there.
The current default, 7, is, to put it nicely, absolutely ridiculous.
On 2.4 GHz, the only channels you should use are 1, 6 and 11, because
every other channel overlaps one of those and causes interference.
On 5/6 GHz, channel 7 does not exist at all.
Also, it's 2024, most things will support automatic channel selection,
and those that don't will likely need extra care to support prehistoric
hardware anyway.
That was... interesting to debug. It took a me a bit of reading C code
until I realized that the realpath cache is internally used for
`file_get_contents`, but not for `file_exists` 🙃
I'm not comfortable on doing the workaround in the module, but I think
it's good to have this documented in the manual.
