Maximilian Bosch 003132c2dd
nixos/prometheus: make source_labels optional
It's possible to skip `source_labels` entirely, an example for this is
the blackbox exporter configuration:

https://github.com/prometheus/blackbox_exporter#prometheus-configuration
2019-01-16 14:01:43 +01:00
..
2018-09-29 20:51:11 -04:00