In the Jenkins UI, I have OpenID Federated Login
under configureSecurity
http://XXXXXX:YYYY/configureSecurity/
How can I enable the script security checkbox from the server-side (which file in JENKINS_HOME holds it)?
When you tick/untick the checkbox, the file /var/lib/jenkins/javaposse.jobdsl.plugin.GlobalJobDslSecurityConfiguration.xml gets updated.
The below value gets updated to true when you tick the checkbox;
<useScriptSecurity>true</useScriptSecurity>
You need to restart jenkins service for changes to reflect. I'm not sure about what other service needs to be restarted for changes to reflect as from the console doing a simple save or apply is suffice and we don't have to restart jenkins service