build@c7rpm:/home/build/git/rheldap/RHEL7_x86_64/BUILD...lapd Jul 18 11:55:29 localhost.localdomain slapd[2133]: main: TLS init def ctx failed: -1 Jul 18 11:55:29 localhost.localdomain slapd[2133]: Enter PEM pass phrase:This clearly indicates your key file is password protected, which is not supported.
To be clear, it's not supported to use a password protected key file and then try and start slapd via an automated init system such as systemd. To use a password protected key file requires that you start slapd manually so you can provide the password as part of the startup process so slapd can access it.
Regards, Quanah -- Quanah Gibson-Mount Product Architect Symas Corporation Packaged, certified, and supported LDAP solutions powered by OpenLDAP: <http://www.symas.com>