Metrics not gathered after ip change

[gruyaume]

Bug Description

When the AMF (or any other network function) changes IP address, the IP address in the prometheus_scrape integration (prometheus_scrape_unit_address unit relation data) is not updated.

Note: This issue also occurs in mongodb, we should probably also open the bug in their repo to let the data platform team know about this situation.

Root cause

The prometheus class only listens to relation changed which does not seem to update when the pod IP changes.

Possible solution

We could pass update status as a refresh event to the Prometheus class.

To Reproduce

1. Deploy core network
2. Integrate with COS
3. Kill one pod

Environment

N/A

Relevant log output

N/A

Additional context

I'm opening this bug on a different system from the one running the setup, hence the lack of logs.

[dariofaccin]

I also opened this feature request to address this issue.