Similar to cert-manager controllers (https://cert-manager.io/docs/devops-tips/prometheus-metrics/#scraping-metrics), csi-lib should expose some key metrics for promethues to scrap, like:

• CertificateRequest status (number issued, approved/denied, failed, etc)

  certmanager_certificate_ready_status
  

• Near expiry CertificateRequests (how many dates left to renew)

  certmanager_certificate_expiration_timestamp_seconds
  

See related discussion in #51 (comment)