Allow prometheus to scrape metrics

[bartusz01]

Describe the problem

Currently weblate offers two formats, "json" and "api" to expose metrics
https://docs.weblate.org/en/latest/api.html,

Prometheus only supports "text/plain; version=0.0.4", see here: https://prometheus.io/docs/instrumenting/exposition_formats/

So prometheus is not able to scrape weblate metrics, unless creating/deploying a json exporter.

Describe the solution you'd like

a third option to weblates REST API response format (for /api/metrics/)

Describe alternatives you've considered

deploying additionally an unofficial json exporter

Screenshots

No response

Additional context

No response

[github-actions]

This issue has been added to the backlog. It is not scheduled on the Weblate roadmap, but it eventually might be implemented.

In case you need this feature soon, please consider helping or push it by funding the development.

[github-actions]

Thank you for your report; the issue you have reported has just been fixed.

• In case you see a problem with the fix, please comment on this issue.
• In case you see a similar problem, please open a separate issue.
• If you are happy with the outcome, don’t hesitate to support Weblate by making a donation.