Can’t add a service to startup on CentOS/RHEL

Ran into this while doing some routine work: couldn’t add a custom service to startup.
Figured I’d write a quick note about it.

Running:

chkconfig service_name on

or

chkconfig -add service_name

throws this error:

service service_name does not support chkconfig

To add your service_name service to startup anyway, edit its init.d script:

nano /etc/init.d/service_name

Add this right after the first line:

# chkconfig: 2345 95 20
# description: service description
# processname: service_name