Jenkins Groovy script to wipe all workspaces from disk

wipe_jenkins_workspaces.groovy

import com.cloudbees.hudson.plugins.folder.*
import org.jenkinsci.plugins.workflow.multibranch.WorkflowMultiBranchProject
import org.jenkinsci.plugins.workflow.job.WorkflowJob

for (item in Hudson.instance.items) {
    wipeWorkspace(item)
}

def wipeWorkspace(item) {
    println("--> found " + item.getClass().getCanonicalName())
    if (item instanceof Folder) {
        println("    -> entering folder: " + item.name)
        for (innerItem in item.getItems()) {
            wipeWorkspace(innerItem)
        }
    } else if (item instanceof Job) {
        if (!item.isBuilding()) {
            println("    wiping workspace: " + item.name)
            item.doDoWipeOutWorkspace()
        } else {
            println("    skipping: " + item.name + " (build in progress)")
        }
    } else if (item instanceof WorkflowJob || item instanceof WorkflowMultiBranchProject) {
        // can't handle workflow (i.e. pipeline) jobs
        println("    skipping: " + item.name + " (workflow job)")
    } else {
        println("    unsupported job type: " + item.name + " (" + item.getClass().getCanonicalName() + ")")
    }
}