Add useful metrics to ocis services

[butonic]

implement collecting metrics for all services.

• ocis-glauth might be a quick win because it already collects stats. we may just need to expose them correctly
• ocis-glauth together with ocis-hello could then be the blueprint for how to add it to other services

minimum metrics to collect: RED

• (Request) Rate - the number of requests, per second, you services are serving.
• (Request) Errors - the number of failed requests per second.
• (Request) Duration - distributions of the amount of time each request takes.

Libs to consider

• https://github.com/rcrowley/go-metrics

See also:

• https://prometheus.io/docs/practices/naming/
• https://prometheus.io/docs/guides/go-application/
• how glauth collects stats for the frontend and backend
• https://github.com/monitoringsucks/metrics-catalog

Bonus points for adding and enabling prometheus to

• [ ] the docker compose setup
• [ ] the helm charts
• [ ] the docs for ocis and the individual extensions

Needs order of extensions

• proxy
• reva services
• thumbnails
• accounts
• settings

[exalate-issue-sync[bot]]

Remote key is https://jira.owncloud.com/browse/OC-2010