What I want to achieve:

• I want to have a cron job in Jenkins that will help me delete the build history of some of the stale branches in my Multibranch pipeline. That is, inside the Multibranch pipeline named Demo, check for stale branches older than three months, then delete the build history there.

Context:

• I have a Multibranch pipeline named Demo. It is linked to my Github, hence, inside the pipeline it contains a number of branches. Normally, I can delete the build history of the branches on the Jenkins UI but this is very stressful. Is there a way I can have a cron job or groovy script that will help achieve this?

What I have so far:

import com.cloudbees.hudson.plugins.folder.Folder
import jenkins.model.Jenkins
import org.jenkinsci.plugins.workflow.multibranch.WorkflowMultiBranchProject

int months = 3

int totalJobs = 0
int totalBuilds = 0
int olderThanThreeMonths = 0

String targetJobName = 'demo'

// Find the multibranch pipeline project named 'demo'
def targetJob = Jenkins.instance.getAllItems(WorkflowMultiBranchProject).find { it.fullName == targetJobName }

if (targetJob) {
    println "Found multibranch pipeline named '${targetJobName}'"
    
    // Count the total number of branches (WorkflowJobs) in the multibranch pipeline
    int branchCount = targetJob.items.size()
    println "Total number of branches: ${branchCount}"

I am very new to groovy. Started learning just yesterday. I am able to print the total number of branches in the pipeline which works, but I am finding it difficult to check for branches older than three months, and inside the branch, delete the build history to free up space.

Kindly help. Thanks.