Certificate Expires Soon (Mac OS X Server)
Since a week or so I am receiving daily emails from my Mac Mini (running Mac OS X Server) that some certificates are expiring soon. Some of them could be easily renewed using Server.app by going to the Alerts and clicking on ‘Renew’.
But some of them there is only the warning but not an option to renew the certificates
Alerts in Server.app
Doing a Google search on Certificate Expires Soon - APSP brought me to a support article aptly titled Mac OS X Server: Software Update Certificate expiration. The article, besides confirming the certificates were related to rhe Software Update services, did not provide any useful information on how to solve the issue.
The Google search also gave a link to a discussion on the Apple Support Communities forum which proved to be more helpful, describing at least two possible solutions;
- Turn off Push Notifications which triggers a check to be performed and then provides an option to renew the certificate(s)
- Delete certificates from the file-system (/etc/certificates) and Keychain Access
The first option looks to be less destructive (i.e. renewing instead of just deleting the offending certificates), so that is the option I tried first.
In my case turning push notifications off and on did not do the trick. Sometime ago I changed my Apple ID to a different email address, so I first needed to change my Apple ID to the new email address. This automatically renewed the (or created new) certificates.
Server.app - Settings 
Server.app - Push Notifications
The certificates in Keychain Access before the change 
and after the change 
So again all is well…