Metrics endpoint for prometheus

[jpds]

• Gitea version (or commit ref): 1.2.0+1-g670562a
• Git version: 1.2.0+1-g670562a
• Operating system: Docker image
• Database (use [x]):
  • PostgreSQL
  • MySQL
  • MSSQL
  • SQLite
• Can you reproduce the bug at https://try.gitea.io:
  • Yes (provide example URL)
  • No
  • Not relevant

Description

I would like gitea to expose a /metrics endpoint (can be on a different port from main Gitea) which could be used in conjunction with Prometheus to get information about:

• Page load latencies
• Number of git repos in gitea
• Time taken to pull a mirror repository down
• Number of users in Gitea
• Number of users logged into Gitea
• Number of failed log in attempts
• Any other metric you folks can think of :)

Once this information is in Prometheus, I can then use Grafana to create a dashboard for Gitea metrics.

[cez81]

Some work has been done previously in #678.

[techknowlogick]

Closed as linked PR has been merged.