Jenkins Script Tutorial

jenkins_script_console.md

Jenkins Script Console Tutorial

Jenkins script console allows one to run groovy scripts/code to automate jenkins setup e.g installing plugins, setting configuration parameters. These groovy scripts can be run either through the web ui, or event loaded as scripts using curl from command line. With these groovy scripts, jenkins configurations can be completely automated.

Lets explore this script console and learn how to write/load simple scripts.

Exploring script console

From the jenkins UI, choose Jenkins => Manage Jenkins => Script Console . You should see script console installed, in which run the following,

println(Jenkins.instance.pluginManager.plugins)

Jenkins.instance

Jenkins.instance.metaClass.methods*.name

Installing Plugins

Lets pick a script which installs a git plugin, copy it to script console and run.

import jenkins.model.*

def pluginParameter="git slack"
def plugins = pluginParameter.split()
println(plugins)
def instance = Jenkins.getInstance()
def pm = instance.getPluginManager()
def uc = instance.getUpdateCenter()
def installed = false

plugins.each {
  if (!pm.getPlugin(it)) {
    def plugin = uc.getPlugin(it)
    if (plugin) {
      println("Installing " + it)
      plugin.deploy()
      installed = true
    }
  }
}

instance.save()
if (installed)
instance.doSafeRestart()

source : https://stackoverflow.com/questions/31457623/jenkins-plugin-installation

Exercise

• Observe what happens after running the above groovy script ? Did the plugin get installed? Check by running the println command that we run earlier to list the plugins.
• Install the following plugins
  • slack
  • jira

Running Groovy Scripts from command line console

Lets write a groovy script which will update the admin email address for jenkins. You could view the current configs at Manage Jenkins => Configure Systems => System Admin e-mail address

File: update_admin_email.groovy

import jenkins.model.*
def jenkinsLocationConfiguration = JenkinsLocationConfiguration.get()
jenkinsLocationConfiguration.setAdminAddress("[Super User] <super@user.org>")
jenkinsLocationConfiguration.save()

Before we send this script to jenkins, find out the jenkins uri. e.g. http://139.59.0.187:8081/ We also need to get a CSRF token, which is then used as part of subsequent payload. This is part of additional security measures enabled by default as part of Jenkins 2.0.

mytoken=$(curl --user 'admin:admin' -s http://<jenkins_uri>/crumbIssuer/api/json | python -c 'import sys,json;j=json.load(sys.stdin);print j["crumbRequestField"] + "=" + j["crumb"]')

where replace <jenkins_uri> with actual.

e.g.

mytoken=$(curl --user 'admin:admin' -s http://139.59.0.187:8081/crumbIssuer/api/json | python -c 'import sys,json;j=json.load(sys.stdin);print j["crumbRequestField"] + "=" + j["crumb"]')

And load the groovy script

curl --user 'admin:admin'   -d "$mytoken"   --data-urlencode "script=$(<./<script_name>)" http://<jenkins_url>/scriptTex

e.g.

curl --user 'admin:admin'   -d "$mytoken"   --data-urlencode "script=$(<./update_admin_email.groovy)" http://139.59.0.187:8081/scriptTex

Validate if the email is changed by visting Manage Jenkins => Configure Systems => System Admin e-mail address

Reading List

• Script Console Demo: https://www.youtube.com/watch?v=T1x2kCGRY1w
• Script Console Doc: https://wiki.jenkins.io/display/JENKINS/Jenkins+Script+Console
• Jobs DSL PLugin