Adds a `config` label (similar to `prometheus_sd_discovered_targets`) to
refresh metrics to help identify the source of refresh issues or
performance stats. In particular for HTTP SD, it can be common to have
multiple disparate HTTP SD sources that should be identified and not
lumped together. For example if one HTTP SD service has failures, that
should be evident in its own time series seperate from other HTTP SD
sources.
`config` seemed more appropriate than `endpoint` as a general standard
for `prometheus_sd` metrics.
Docs were also updated for HTTP SD to point at the new refresh metrics
rather than the older metrics.
Signed-off-by: Will Bollock <wbollock@linode.com>
SD Managers take over responsibility for SD metrics registration
---------
Signed-off-by: Paulin Todev <paulin.todev@gmail.com>
Signed-off-by: Björn Rabenstein <github@rabenste.in>
Co-authored-by: Björn Rabenstein <github@rabenste.in>
