Custom selector for prometheus service auto discovery

[mrueg]

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The auto discovery of prometheus uses hardcoded labels which just gets longer and longer.

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Allow the user to specify selectors that point to the right service.

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Forking the repo
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[aantn]

Hi @mrueg, we are open to a PR for this! Absolutely.

[aantn]

It would be best to base the PR on the prometheus-workload-loader branch which has some major changes that will be merged soon.

[aantn]

One more thing: note that as a workaround you may be able to use --prometheus-url