Grafana: include certs where renewal time is exceeded in Radix Overview dashboard

[nilsgstrabo]

Cert manager does not provide metrics for pending or failing certrequests or orders.
If any of these are pending for a long time, e.g. due to incorrect configuration of cert-manager components, then the only way to detect that something is wrong, is by checking if the renewal time for the certificate has expired. The renewal time is exposed in a metric called certmanager_certificate_renewal_timestamp_seconds.

Include this metric in the existing Radix Overview metric, e.g.

(sum(certmanager_certificate_ready_status{RadixCluster="prod",  condition!="True"}) + (vector(1) and on() (certmanager_certificate_renewal_timestamp_seconds{RadixCluster="prod"} - time() < 0)) or on() vector(0)) > bool 0