Expose /metrics endpoint through unauthenticated access #364
Description
Is your request related to a problem? Please describe.
For many cases, such as exposing to an external provider, it would be nice to be able to expose the /metrics endpoint via an unauthenticated connection like we do /events to certain IP ranges (our Prometheus server, or DataDog collectors, or whatever).
Describe the solution you'd like.
The best method here is probably to just define another variable like allow_unauthenticated_metrics_cidr_blocks and allow_unauthenticated_metrics_priority as there is for github webhooks, and then add a new aws_alb_listener_rule resource similar to the one for /events.
Describe alternatives you've considered.
We can add this listener rule resource ourself outside of the module (which is what we're doing now) but it would be nicer if it was just integrated into the module.