Prometheus Metrics Best Practices

ISSUE TYPE

• Make sure that exported metrics conform with Prometheus best practices

SUMMARY

I have made a PR at Prometheus docs to add AWX as a software exposing Prometheus metrics (https://github.com/prometheus/docs/pull/1685#issuecomment-649323355) and after a quick peek at AWX metrics code from @brian-brazil, he appointed a few things to change. I have see a few others open issues about metrics too, so maybe a check with a guideline or something like that can benefit AWX monitoring.

NOTE: I am not familiar with any of the code bases of the projects, I am simply messenger interested in both projects.