Delete old builds from all configured Jobs in Jenkins, in a selective way.

builds_cleaner.groovy

import jenkins.model.Jenkins
import hudson.model.Job
 
int MAX_BUILDS_TO_KEEP = 5
 
Jenkins.instance.getAllItems(Job.class).each { job ->

    job.builds.drop(MAX_BUILDS_TO_KEEP).findAll {
 
        !it.keepLog &&
        !it.building &&
        it != job.lastStableBuild &&
        it != job.lastSuccessfulBuild &&
        it != job.lastUnstableBuild &&
        it != job.lastUnsuccessfulBuild
 
    }.each { build ->

        build.delete()

    }
}