discard_old_builds.py

import jenkins
import re

server = jenkins.Jenkins('http://ci.saucelabs-sales.net/', username='YOUR_JENKINS_USERNAME', password='YOUR_JENKINS_PASSWORD')
user = server.get_whoami()
version = server.get_version()
jobs = server.get_jobs()

for job in jobs:
    name = job['fullname']

    try:
        config = server.get_job_config(name)

        if not 'Pipeline' in name:

            update = True

            if '<properties/>' in config:
                new_config = config.replace('<properties/>', '<properties>\n    <jenkins.model.BuildDiscarderProperty>\n      <strategy class="hudson.tasks.LogRotator">\n        <daysToKeep>30</daysToKeep>\n        <numToKeep>30</numToKeep>\n        <artifactDaysToKeep>-1</artifactDaysToKeep>\n        <artifactNumToKeep>-1</artifactNumToKeep>\n      </strategy>\n    </jenkins.model.BuildDiscarderProperty>\n  </properties>')
            elif 'numToKeep' in config and 'daysToKeep' in config:
                new_config = re.sub("<numToKeep>.*</numToKeep>", '<numToKeep>30</numToKeep>', config)
                new_config = re.sub("<daysToKeep>.*</daysToKeep>", '<daysToKeep>30</daysToKeep>', new_config)
            else:
                update = False
                print "Not found in " + name


            if update:
                server.reconfig_job(name, new_config)
    except:
        print "Error reconfiguring: " + name