Add Total Topics and Total Subscriptions to the `/v1/stats` API

[kevinlutzer]

:bulb: Idea I want to expose the total subscriptions and topics on the /v1/stats API. The data will be consumed by some of the analytics tools I use to manage my Kubernetes cluster, as well as I want to display these metrics on my Heimdall Dashboard

Looks like the total topics lives on the server struct. Subscriptions would need to be computed in the API based on the Topic.Stats() method pointer.

:computer: Target components

ntfy server

[binwiederhier]

My apologies for not responding earlier, but I do not thing that this info should be exposed in a public endpoint due to security concerts. It leaks info. I realize that the number of messages is already questionable, but I need that to display the nice counter on the website.

[kevinlutzer]

Thanks for your response!

Ahh okay no worries! Ya I thought that if you were comfortable with the total message quantity and message rate metrics being exposed via API that there wouldn't be an issue with showing the total number of topics, subscriptions etc.

Is there another way it would be possible to expose these metrics? Maybe behind an auth'd API?

[binwiederhier]

I could see the stats API returning more stats when queried by an admin user, which should be relatively easy to achieve. Basically return the same stuff that the metrics endpoint would.

[kevinlutzer]

Are you referring to this file as the "metrics endpoint" -> https://github.com/binwiederhier/ntfy/blob/main/server/server_metrics.go

[binwiederhier]

Yeah, the prometheus endpoint is how you'd usually get metrics. It's pretty awesome.