prometheus exporter research

[psilabs-dev]

issue: Difegue#1080

relevant libraries:

• https://metacpan.org/pod/Net::Prometheus (is being maintained by pevans)
• https://metacpan.org/pod/Mojolicious::Plugin::Prometheus (uses Net::Prometheus 0.05)
• https://metacpan.org/pod/Prometheus::Tiny

relevant articles:

• https://metacpan.org/pod/PSGI
• https://prometheus.io/docs/introduction/overview/
  • definitely more towards availability/reliability than accuracy.
• https://devopscube.com/prometheus-architecture/
• https://docs.mojolicious.org/Mojolicious/Controller
• cloudflare prometheus scaling
• prometheus optimization
• https://last9.io/blog/best-practices-using-and-writing-prometheus-exporters/

relevant Prometheus documentation:

• Metric and label naming
• Writing Exporters