kubernetes-operator/website/content/en/docs/Getting Started/v0.2.0/customization.md

title	linkTitle	weight	date	description
Customization	Customization	3	2019-08-05	How to customize Jenkins

Jenkins can be customized using groovy scripts or configuration as code plugin. By using ConfigMap you can create own Jenkins customized configuration. Then you must reference the ConfigMap in Jenkins pod customization file in spec.groovyScripts or spec.configurationAsCode

For example create ConfigMap with name jenkins-operator-user-configuration. Then, modify the Jenkins manifest to look like this:

apiVersion: jenkins.io/v1alpha2
kind: Jenkins
metadata:
  name: example
spec:
  configurationAsCode:
    configurations: 
    - name: jenkins-operator-user-configuration
  groovyScripts:
    configurations:
    - name: jenkins-operator-user-configuration

Here is example of jenkins-operator-user-configuration:

apiVersion: v1
kind: ConfigMap
metadata:
  name: jenkins-operator-user-configuration
data:
  1-configure-theme.groovy: | 
    import jenkins.*
    import jenkins.model.*
    import hudson.*
    import hudson.model.*
    import org.jenkinsci.plugins.simpletheme.ThemeElement
    import org.jenkinsci.plugins.simpletheme.CssTextThemeElement
    import org.jenkinsci.plugins.simpletheme.CssUrlThemeElement

    Jenkins jenkins = Jenkins.getInstance()

    def decorator = Jenkins.instance.getDescriptorByType(org.codefirst.SimpleThemeDecorator.class)

    List<ThemeElement> configElements = new ArrayList<>();
    configElements.add(new CssTextThemeElement("DEFAULT"));
    configElements.add(new CssUrlThemeElement("https://cdn.rawgit.com/afonsof/jenkins-material-theme/gh-pages/dist/material-light-green.css"));
    decorator.setElements(configElements);
    decorator.save();

    jenkins.save()
  1-system-message.yaml: |
    jenkins:
      systemMessage: "Configuration as Code integration works!!!"    

• *.groovy is Groovy script configuration
• *.yaml is configuration as code

If you want to correct your configuration you can edit it while jenkins-operator is running. Jenkins will reconcile and apply new configuration.

Using secrets inside Groovy script

If you configured spec.groovyScripts.secret.name, then this secret is available to use inside map Groovy scripts. The secrets are loaded to secrets map.

Create a secret with for eg. jenkins-conf-secrets name.

kind: Secret
apiVersion: v1
type: Opaque
metadata:
  name: jenkins-conf-secrets
  namespace: default
data:
  SYSTEM_MESSAGE: SGVsbG8gd29ybGQ=

Then modify the Jenkins pod manifest by changing spec.groovyScripts.secret.name to jenkins-conf-secrets.

apiVersion: jenkins.io/v1alpha2
kind: Jenkins
metadata:
  name: example
spec:
  configurationAsCode:
    configurations: 
    - name: jenkins-operator-user-configuration
    secret:
      name: jenkins-conf-secrets
  groovyScripts:
    configurations:
    - name: jenkins-operator-user-configuration
    secret:
      name: jenkins-conf-secrets

Now you can test that the secret is mounted by applying this ConfigMap for Groovy script:

apiVersion: v1
kind: ConfigMap
metadata:
  name: jenkins-operator-user-configuration
data:
  1-system-message.groovy: | 
    import jenkins.*
    import jenkins.model.*
    import hudson.*
    import hudson.model.*
    Jenkins jenkins = Jenkins.getInstance()
    
    jenkins.setSystemMessage(secrets["SYSTEM_MESSAGE"])
    jenkins.save()

Or by applying configuration as code:

apiVersion: v1
kind: ConfigMap
metadata:
  name: jenkins-operator-user-configuration
data:
  1-system-message.yaml: |
    jenkins:
      systemMessage: ${SYSTEM_MESSAGE}    

After this, you should see the Hello world system message at Jenkins homepage.

Install Plugins

Edit CR under spec.master.plugins:

apiVersion: jenkins.io/v1alpha2
kind: Jenkins
metadata:
  name: example
spec:
  master:
   plugins:
   - name: simple-theme-plugin
     version: 0.5.1

Under spec.master.basePlugins you can find plugins for valid jenkins-operator work:

apiVersion: jenkins.io/v1alpha2
kind: Jenkins
metadata:
  name: example
spec:
  master:
    basePlugins:
    - name: kubernetes
      version: 1.18.3
    - name: workflow-job
      version: "2.34"
    - name: workflow-aggregator
      version: "2.6"
    - name: git
      version: 3.12.0
    - name: job-dsl
      version: "1.76"
    - name: configuration-as-code
      version: "1.29"
    - name: configuration-as-code-support
      version: "1.19"
    - name: kubernetes-credentials-provider
      version: 0.12.1

You can change version of them.

Then jenkins-operator will automatically install plugins after Jenkins master pod restart.