check_expired_certificates: automated certificate nenewal for letsencrypt
This change reduce maintenance effort by automating certificate r…
check_expired_certificates: automated certificate nenewal for letsencryptThis change reduce maintenance effort by automating certificaterenewal. When the NaviServer letsencrypt module is installed andconfigured, the background operation check_expired_certificates willautomatically update the certificates when these expire soon (asdefined by the "ExpireCertificateWarningPeriod" parameter ofacs-admin). When a recent version of NaviServer is used that supportscertificate refetch on SIGHUP, the new certificates are automaticallyupdated without a server restart.Prerequisites:- Recent version of letsencrypt NaviServer module installed (0.6) and configured- Recent version of NaviServer (currently Bitbucket tip) for automated certificate reloadingWhen the recent letsencrypt module is not installed,check_expired_certificates sends expiration warnings as usual.Therefore, it is also useful for sites using certificates fromdifferent sources.This new functionality was used for latest certificate renewal onopenacs.org.