Export DNS metrics

[laurivosandi]

We had Fluent bit hang up due to DNS resolution failure, but it seems /api/v1/metrics/prometheus endpoint does not provide any useful metrics to monitor for this. The fluentbit_output_errors_total stays at 0

[github-actions]

This issue is stale because it has been open 90 days with no activity. Remove stale label or comment or this will be closed in 5 days. Maintainers can add the exempt-stale label.

[github-actions]

This issue was closed because it has been stalled for 5 days with no activity.

[EppO]

I think this feature request is legit, we're also having some DNS errors that would be worth exposing as stats:

[2022/10/18 13:02:52] [ warn] [net] getaddrinfo(host='logging-operator-logging-fluentd.logging-operator.svc', err=12): Timeout while contacting DNS servers

[laurivosandi]

We just gave up using Fluent Bit. It just does not work reliably