Apply filters on prometheus 'up' metrics

[ChrsMark]

Closes #16564

[mtojek]

Ok, I see what you did here.

I'm not sure if it isn't safer to keep the family == nil check here, but split the whole method body into two methods: skipFamily and skipFamilyName. WDYT? It might prevent next developers from making mistakes (nil structure).

[mtojek]

If it's doesn't blow up any system tests, please consider these changes approved. Thanks!

[dagwieers]

We cannot make the regexp matching work. So if we want to exclude all metrics ending in e.g. _sum or _max it currently does not seem possible.

This PR also did not add any tests wrt. regexp matching.

[ChrsMark]

We cannot make the regexp matching work. So if we want to exclude all metrics ending in e.g. _sum or _max it currently does not seem possible.

This PR also did not add any tests wrt. regexp matching.

Hi!

Tests had been added on the PR(#16420) that originally added this functionality (https://github.com/elastic/beats/pull/16420/files#diff-5945e5b443352401ece4bbac9bbb653cR205).
In addition this feature is also used by other modules under the hood like redisenterprise

beats/x-pack/metricbeat/module/redisenterprise/proxy/manifest.yml

Line 7 in d01106b

metrics_filters:

and is there are no issues reported so far.

For such questions please refer to https://discuss.elastic.co/tags/c/elastic-stack/81/metricbeat.

[dagwieers]

There are no regexp tests, I added some myself and they do work correctly locally on the master build. But it does fail to process/match regex excludes using metricbeat 7.9.1 on CentOS (installed using the RPM). Even the example regex (^async_dgcjobs_seconds_sum$) fails to exclude it on our system. No regex matching works (not even .*_sum$).

I will propose a PR adding those regex matching examples to the tests.