Prometheus set interface

Description:

If i enable Prometheus Metrics by ticking the box in the admin interface/Logs, Rocketchat binds the selected port on all available interfaces, which exposes the information publicly. Since i'm using a reverse proxy i would love to bind the metrics to the loopback only.

I can enter the ip address in the webinterface with no error, but the port never opens then.

Steps to reproduce:

1. Go to Logs
2. Enable Prometheus
3. Enter something like "127.0.0.1:1337" as port
4. Save and restart

Expected behavior:

Port 1337 with Prometheus metrics opens at 127.0.0.1

Actual behavior:

No port opens at all, no errors in logging.

Server Setup Information:

• Version of Rocket.Chat Server: 0.74.2
• Operating System: Ubuntu Linux
• Deployment Method: manual

Additional context

Binding to a specific interface could help to control access to metrics with allow/deny directives in the reverse proxy, also could provide TLS encryption.

Start from the Logs admin interface and trace how the Prometheus address is parsed and passed to the metrics listener. Reproduce the configuration with 127.0.0.1:1337, then verify that metrics bind only to that interface and that invalid or existing configurations still report appropriately.