Design Issue: #159

Personas / User Stories
As someone responsible for managing TLS/SSL Certificates
I want be able to view a table of all current TLS certificates where I can determine which are in danger of becoming invalid due to either expiration or advanced age (e.g. Safari)
So that my services that rely on these certificates remain available

ACs:

• Unique page in Uptime that shows a table
• Regular EUI Table that contains following columns:
  • status + reason (reason being the error state that is most urgent, either "expires soon" or "approaching age limit".
  • Common Name (plus x more indicator),
  • the monitor names that contain endpoints/domains with that certificate
  • expiration date/time (col name "Valid until")
  • age of the certificate in days
  • Issuer Name,
  • current status (ie OK, warning, alert).
  • Fingerprints Column (Showing empty buttons for SHA-1 and SHA-256 and a copy icon, shows a tooltip with the full SHA on hover. Screenshot further down in the comments.)
• Alert state column rules match triggers for sending an actual alert
• Additional data for heartbeat to capture: SHA fingerprint, all domains covered by the certificate, valid from, valid to, issuing authority
• Search: Wildcards on monitor name, monitor ID, issuer.distinguished_name, subject.distinguished_name, common name case insensitively
• Settings page adds:
  • "Certificate expiration warning threshold": default: 30 days
  • "Certificate age warning threshold" : default: 365 days
  • Descriptions for both fields say: "Change the threshold for displaying and alerting on certificate errors. Note, this will affect any configured alerts"
• Pagination size should be remembered in local storage as-in overview page and ping history
• All columns are sortable