The old way of writing the file omited qoutes within strings which are needed by some configurations like federations.
The quotes got lost when `echo`ing the content via `echo '${builtins.toJSON x}'`.
The pkgs.formats.json does handle that race condition properly, so this commit switches the writing to that helper.
Fixes race conditions like this:
> systemd[1]: Started prometheus-kea-exporter.service.
> kea-exporter[927]: Listening on http://0.0.0.0:9547
> kea-exporter[927]: Socket at /run/kea/dhcp4.sock does not exist. Is Kea running?
> systemd[1]: prometheus-kea-exporter.service: Main process exited, code=exited, status=1/FAILURE
When no devices are given the exporter tries to autodiscover available
disks. The previous DevicePolicy was however preventing the exporter
from accessing any device at all, since only explicitly mentioned ones
were allowed.
This commit adds an allow rule for several device classes that I could
find on my machines, that gets set when no devices are explicitly
configured.
There is an existing problem with nvme devices, that expose a character
device at `/dev/nvme0`, and a (namespaced) block device at
`/dev/nvme0n1`. The character device does not come with permissions that
we could give to the exporter without further impacting the hardening.
crw------- 1 root root 247, 0 27. Jan 03:10 /dev/nvme0
brw-rw---- 1 root disk 259, 0 27. Jan 03:10 /dev/nvme0n1
The autodiscovery only finds the character device, which the exporter
unfortunately does not have access to.
However a simple udev rule can be used to resolve this:
services.udev.extraRules = ''
SUBSYSTEM=="nvme", KERNEL=="nvme[0-9]*", GROUP="disk"
'';
Unfortunately I'm not fully aware of the security implications this
change carries and we should question upstream (systemd) why they did
not include such a rule.
The disk group has no members on any of my machines.
❯ getent group disk
disk❌6:
This option makes the complete netdata configuration directory available for
modification. The default configuration is merged with changes
defined in the configDir option.
Co-authored-by: Michael Raitza <spacefrogg-github@meterriblecrew.net>
some options have default that are best described in prose, such as
defaults that depend on the system stateVersion, defaults that are
derivations specific to the surrounding context, or those where the
expression is much longer and harder to understand than a simple text
snippet.
adds defaultText for all options that use `cfg.*` values in their
defaults, but only for interpolations with no extra processing (other
than toString where necessary)
