1 CheatSheet: Jenkins & Groovy

• PDF Link: cheatsheet-jenkins-groovy-A4.pdf, Category: languages
• Blog URL: https://cheatsheet.dennyzhang.com/cheatsheet-jenkins-groovy-A4
• Related posts: Jenkins CheatSheet, #denny-cheatsheets

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1.1 Jenkins Pipeline

Name	Comment
Specify parameter to run jobs	build job:'job1', parameters:[string(name:'name1', value:va1)]
Run job in different agents	node($agent_label) {...}
Ask for user input	stage('stage2'){ input "OK to go?" }
Actively fail current pipeline job	error("Build failed because of this and that..")
List all Jenkins plugins and versions	list-all-plugins.groovy
Check whether property exists	if (env.keep_failed_env)
Jenkins Pipeline enable timestamps	options{timestamps()}
Set envs within a jenkins pipeline	withEnv(["key1=$var1"])
Install plugin via groovy	Hudson.instance.updateCenter.getPlugin(plugin).deploy().get()
Keep previous job run via groovy	buildDiscarder(logRotator(daysToKeepStr: '20', numToKeepStr: '60'))
Customize job workspace	=customWorkspace “/some/other/path”=
git scm checkout to relative directory	extensions: [[$class: 'RelativeTargetDirectory', relativeTargetDir: 'XXX']]
Keep going when previous stage has failed	keep-going-with-errors.groovy
Send slack notification in pipeline	slack-notification.groovy
Pass parameter across jenkins jobs	jenkinsfile-pass-parameter.groovy
Set timeout & retry	jenkinsfile-timeout-retry.groovy
Use finally to do cleanup	jenkinsfile-finally.groovy
Run jenkins jobs in a sequential way	jenkinsfile-sequentially.groovy
Run jenkins jobs in parallel	jenkinsfile-parallelly.groovy
Reference	Link: Syntax Reference, Link: Jenkins User Documentation
Reference	Link: Groovy Language Documentation
Reference	Link: Example, Link: Example

1.2 Config Jenkins Via Groovy

Name	Comment
Set timezone for jenkins	timezone.groovy
Set timezone for jenkins	System.setProperty('org.apache.commons.jelly.tags.fmt.timeZone', 'America/Los_Angeles')
Configure default view	jenkins-views.groovy
Configure Jenkins url	jenkins-url.groovy
Create a Jenkins user	create-jenkins-user.groovy
Groovy manages files/folders	files-folder.groovy
Configure max executors in Jenkins	master-executors.groovy
Configure only 1 executor per worker	For each agent, configure # of executors
Configure slack plugin	config-slack.groovy
Configure pipeline shared libraries	config-pipeline-library.groovy
Get jenkins version from CLI	java -jar /usr/share/jenkins/jenkins.war --version
Reference	GitHub: cloudbees/jenkins-scripts, GitHub: jenkinsci/pipeline-examples

1.3 Jenkins Trouble Shooting

Name	Comment
List performance metrics for each Jenkins agents	list-all-jenkins-agent.sh

1.4 Jenkins Kubernetes Via Groovy

Name	Comment
Config jenkins kubernetes plugin	jenkins-kubernetes-cloud.groovy
Validate Kubernetes jenkins setup	validate-kubernetes-cloud.groovy
Kubernetes run with envs configured	runWithEnvVariables.groovy
Reference	GitHub: kubernetes-plugin pipeline examples

1.5 Jenkins View Via Groovy

Name	Comment
Add a list of jobs by regexp to a view	myView.setIncludeRegex(".*Integration.*"), addjobstoview-byregexp.groovy
Create jenkins views and add jobs to it	jenkins-views.groovy
Add a view of build monitor view plugin	build-monitor-views.xml
Change view description in groovy	myView.doSubmitDescription

1.6 Jenkins Job Via Groovy

Name	Comment
List all my jenkins jobs	println Jenkins.instance.projects.collect { it.name }
List all jenkins jobs	list-all-jobs.groovy
Create and trigger a job	create-jenkins-job.groovy
Manage jenkins jobs	manage-jenkins-jobs.groovy
Cancel queued jenkins jobs by regexp	kill-queued-jenkins.groovy
Support HTML for job and parameter descriptions	Link: OWASP Markup Formatter Plugin

1.7 Jenkins Different Parameters

Name	Comment
string	string(name: 'key1', defaultValue: 'Default value', description: 'some parameter')
text	text(name: 'key1', defaultValue: 'Default value', description: 'some parameter')
boolean	booleanParam(name: 'key1', defaultValue: true, description: 'some parameter')
choice	choice(name: 'key1', choices: 'One\nTwo\nThree\n', description: 'some parameter')
password	password(name: 'key1', defaultValue: 'SECRET', description: 'Enter a password')
file	file(name: 'key1', description: 'Choose a file to upload')

1.8 Jenkins Security Via Groovy

Name	Comment
logged-in users can do anything	logged-in-users.groovy
Enable ldap in Jenkins	enable-ldap.groovy
Create a jenkins secret text	create-secret-text.groovy
Configure authorization in Jenkins	matrix-authorization-strategy.groovy
Jenkins skip wizzard when initialization	-Djenkins.install.runSetupWizard=false
Jenkins skip wizzard when initialization	instance.setInstallState(InstallState.INITIAL_SETUP_COMPLETED)
Slave To Master Access Control	00-slave-to-master-access.groovy
CSRF Protection	00-csrf.groovy
Add Jenkins permission	jenkins-permission.groovy
Disable CLI over Remoting	00-disable-cli-remoting.groovy
Disable jnlp	jenkins.setSlaveAgentPort(-1)
Access Control for Builds	jenkins.security.QueueItemAuthenticatorConfiguration.xml

1.9 Load Jenkins settings via folder copy

Name	Comment
Add default jobs	Copy jobs/ /usr/share/jenkins/ref/jobs/
Copy custom built plugins	COPY plugins/*.hpi /usr/share/jenkins/ref/plugins/
Use jenkins cli	COPY config/jenkins.properties /usr/share/jenkins/ref/
Add jenkins groovy scripts	COPY config/*.groovy /usr/share/jenkins/ref/init.groovy.d/
Configure Jenkins with some defaults	COPY config/*.xml /usr/share/jenkins/ref/
Install jenkins plugins	/usr/local/bin/install-plugins.sh < /usr/share/jenkins/ref/plugins.txt

1.10 Jenkins Plugins

Plugin	Summary
Kubernetes Plugin	Jenkins plugin to run dynamic agents in a Kubernetes/Docker environment
Credentials Plugin	Load the ssh key
SiteMonitor Plugin	Monitor URLs
Timestamper Plugin	Add timestamp to job output
Dashboard View Plugin	Create dashboard
Log Parser Plugin	Parse the console output and highlight error/warning/info lines.
Build-timeout Plugin	Abort if job takes too long
Naginator Plugin	Retry failed a job
ThinBackup Plugin	Backup jenkins
JobConfigHistory Plugin	Backup job configuration
“Anything Goes” formatter	use JavaScript inside your project description
AnsiColor Plugin	Add support for ANSI escape sequences, including color, to Console Output
Build User Vars Plugin	Describe the user who started the build
Gitlab Plugin	Allows GitLab to trigger Jenkins builds
Workspace Cleanup	Plugin to delete the build workspace.
UpdateSites Manager plugin	manage update sites, where Jenkins accesses in order to retrieve plugins

1.11 Jenkins Git Via Groovy

Name	Comment
Git checkout code	git-checkout.groovy
Get all git commits since last success	git-commits-before-fail.groovy
List git tags and branches	git-list-tags-and-branches.groovy

1.12 Jenkins networking Via Groovy

Name	Comment
Get hostname	println InetAddress.localHost.canonicalHostName
Get IP address	println InetAddress.localHost.hostAddress
Get hostname by ip	get-ip-by-hostname.groovy
validate user input: ip address	assert ip_address.matches("\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}")

1.13 Jenkins with Kubernetes/Docker

Name	Comment
Kubernetes Plugin	Jenkins plugin to run dynamic agents in a Kubernetes/Docker environment
Config jenkins kubernetes plugin	jenkins-kubernetes-cloud.groovy
Cleanup for Docker stale containers/images/volumes	docker-cleanup.groovy
Jenkins customize docker build args	=additionalBuildArgs ‘–build-arg SSH_PRIVATE_KEY…’=

1.14 Groovy Common Errors/Exceptions

Name	Comment
Illegal class name	JVM doesn’t like class names with a hyphen

1.15 Groovy Basic

Name	Comment
Get environment variables	get-env.groovy, println env.WORKSPACE
Groovy execute command	execute-command.groovy
Get data type of a variable	myObject.getClass()
Print stdout	print.groovy echo ‘Action is done’, println “Hello World”
Use boolean parameter	if (istrue == “false”) {…}
Basic integer caculation	def a = 3, b = 7; println “$a + $b = ${a + b}”
Run groovy online	SaaS: Groovy Web console
Run groovy script from Jenkins	Link: Jenkins Script Console
Reference	Link: Apache Groovy

1.16 Groovy String

Name	Comment
Check string startsWith	assert s.startsWith("\t")
Trim whitespaces	s=s.trim()
Concat string	first = 'Joe'; last = 'Smith'; println("Name: $first $last")
Convert list to string	l.join(";")
Create string with multi-lines	multi-line-string.groovy
Convert string to list	split-string.groovy
Convert string to json	string-to-json.groovy
Remove tags	input.replaceAll("\\<.*?>","")
Regex match	regexp-match.groovy

1.17 Groovy Regexp

Name	Comment
Regex case insensitive	(item.name == ~/(?i).*NSX.*/ )
Reference	Regular Expressions in Groovy

1.18 Groovy Array

Name	Comment
Iterate a list	for(item in [1,2,3,4]){ println item }
Iterate a list	(1..3).each { println "Number ${it}"}
Add item to list	def alist = [10, 9, 8]; alist << 7
List size	def alist = [10, 9, 8]; alist.size()
Split string with delimiter	=’1128-2’.tokenize(‘-‘)=

1.19 Groovy File

Name	Comment
Read file into a string	String fileContents = new File('/tmp/test.txt).text
Read file content as a variable	def env = System.getenv(), def content = readFile("/tmp/test.txt")
Write file in pipeline	writeFile file: “output/my.txt”, text: “This is a test”
Read a property file	def conf = readProperties file: “${env.WORKSPACE}@script/my.properties”
Read and write json files	json-file.groovy
Obtain a relative path	relative-path.groovy

1.20 Groovy Shell Command

Name	Comment
Run shell and get output	def out = sh script: command, returnStdout: true
Run shell and get exit code	def status = sh script: command, returnStatus: true

1.21 Groovy Dictionary

Name	Comment
Create a map	def m = ['fruit':'Apple', 'veggie':'Carrot']
Add an item to map	m.put('denny','hello')
Check if key exists	m.containsKey('key1')
Loop a map	loop-map.groovy

1.22 Groovy json

Name	Comment
Convert string to json	string-to-json.groovy
Convert dictionary to json	dict-to-json.groovy
Read and write json files	json-file.groovy

1.23 Groovy Date

Name	Comment
Date to string	new Date().format("yyyy-MM-dd'T'HH:mm:ss'Z'", TimeZone.getTimeZone("UTC"))
String to date	Date.parse("yyyy-MM-dd'T'HH:mm:ss'Z'", "2001-01-01T00:00:00Z")
String to date	Date.parse("yyyy-MM-dd'T'HH:mm:ssZ", "2001-01-01T00:00:00+0000")

1.24 Jenkins Agent

Name	Comment
Check jenkins slave jar version	check-slave-jar-version.groovy
Find dead executors and remove them	find-dead-executors.groovy
Set env for each agent	set-agent-env.groovy

1.25 Jenkins Maintenance

Name	Comment
Delete jenkins job by regexp	delete-job-by-regexp.groovy
Deploy Jenkins via docker	https://hub.docker.com/r/jenkins/jenkins/
Clean up old builds	Link: CloudBees Best Strategy for Disk Space Management

1.26 More Resources

http://groovy-lang.org/documentation.html#gettingstarted

https://github.com/fabric8io/jenkins-docker

License: Code is licensed under MIT License.