Add a way to send metrics to a browser-based client
Context
It will be useful to display metrics in browser-based clients like bgd-browser. At the moment there's no good way for them to get hold of that data though.
We could solve this by adding a websockets endpoint which streams the full set of BuildGrid metrics, or less nicely using a REST endpoint which just returns a custom snapshot of the internal state somehow.
Acceptance Criteria
This is done when there's a way to get service metrics from a browser-based client.
Consider whether the following are required, and complete if so:
-
Unit tests -
Metrics -
Documentation update(s)