Update and align Grafana dashboard to use regex matching for job=~"$job"

[MadLittleMods]

Update and align Grafana dashboard to use regex matching for job=~"$job".

We're already using job=~"$job" in the majority of the other panels. This is just aligning the stragglers.

Background

For a variable in Grafana, when the "All" value is selected, it translates the variable into a wildcard regex. By default, this is just a giant list of all of the possible values or'd together. It's possible to define a "custom all value" like we've done for index as .* and feels like we should also do this in a follow-up PR.

Input:

job="$job"

Before (using exact match) -> resulted in matching nothing:

job="(appservice|background_worker|client_reader|device_lists|event_creator|event_persister|federation_inbound|federation_reader|federation_sender|media_repository|pusher|stream_writers|synapse|synchrotron|user_dir)""

After (using regex match) -> matches all jobs as expected:

job=~"(appservice|background_worker|client_reader|device_lists|event_creator|event_persister|federation_inbound|federation_reader|federation_sender|media_repository|pusher|stream_writers|synapse|synchrotron|user_dir)""

Dev notes

https://prometheus.io/docs/prometheus/latest/querying/basics/#instant-vector-selectors

Pull Request Checklist

• Pull request is based on the develop branch
• Pull request includes a changelog file. The entry should:
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  • Feel free to credit yourself, by adding a sentence "Contributed by @github_username." or "Contributed by [Your Name]." to the end of the entry.
• Code style is correct (run the linters)

[anoadragon453]

Subtle but looks like it would break a lot of things. Thanks!

[MadLittleMods]

Thanks for the review @anoadragon453 🐘