Jenkins Pipeline Expected a Step for Variables & Loop - jenkins

Need help in getting the job status.
I tried the below code, but it is throwing
WorkflowScript: 9: Expected a step # line 9, column 1. def Status = build job: 'Job Regression'
Sample Script:
Pipeline{
agent
stages {
stage('Stg1') {
steps{
Script{
def Status = build job: 'Job Regression'
int build1=0
while(build1==0){
def BStatus = build job: 'JobB', propagate: false
if(BStatus == 'Success'){
build1=0
}```
Thanks in Advance

A few things here.
Perhaps it got lost in the formatting, but please indent your code properly - it will help you, and others, immensely in the future.
Jenkins DSL syntax almost always uses camelCase, and you haven't named some things properly. So your pipeline won't parse correctly the way you've entered it here.
Pipeline must be pipeline
Script must be script
The agent declarative requires an argument. agent any works in most cases, or you can specify labels or types, eg agent { label 'Windows' }
Also maybe lost in formatting, but you must close your braces.
When I fixed these minor issues, it looked like this, and passed validation using the VSCode Jenkins validator:
pipeline{
agent any
stages {
stage('Stg1') {
steps{
script{
def Status = build job: 'Job Regression'
int build1=0
while(build1==0){
def BStatus = build job: 'JobB', propagate: false
if(BStatus == 'Success'){
build1=0
}
}
}
}
}
}
}
Without knowing more about the problem you're coding for, it's hard to say if your actual script here is a good solution or not. What exactly are you trying to do? On the surface, it seems like it could go on forever? You might want to put a timeout on it.
A good place to start looking at your options is https://www.jenkins.io/doc/book/pipeline/syntax/ - the whole "book" is worth a read.

Related

Retrieving an injected build parameter in Pipeline

I'm specifically working on the example below, but I'm guessing the question is a bit more general.
https://github.com/jenkinsci/poll-mailbox-trigger-plugin
States the following build parameters, are injected into the job
pipeline {
agent any
stages {
stage('Test') {
steps {
echo env.pmt_content
echo ${pmt_content}
}
}
}
}
The above methods don't seem to work for me:
How is it possible to retrieve an injected build parameter in a pipeline job?
As explained in the pipeline-plugin tutorial, you can use params to access the job's build parameters.
print params.pmt_content
print "Content is ${params.pmt_content}"

How can I parameterize Jenkinsfile jobs

I have Jenkins Pipeline jobs, where the only difference between the jobs is a parameter, a single "name" value, I could even use the multibranch job name (though not what it's passing as JOB_NAME which is the BRANCH name, sadly none of the envs look suitable without parsing). It would be great if I could set this outiside of the Jenkinsfile, since then I could reuse the same jenkinsfile for all the various jobs.
Add this to your Jenkinsfile:
properties([
parameters([
string(name: 'myParam', defaultValue: '')
])
])
Then, once the build has run once, you will see the "build with parameters" button on the job UI.
There you can input the parameter value you want.
In the pipeline script you can reference it with params.myParam
Basically you need to create a jenkins shared library example name myCoolLib and have a full declarative pipeline in one file under vars, let say you call the file myFancyPipeline.groovy.
Wanted to write my examples but actually I see the docs are quite nice, so I'll copy from there. First the myFancyPipeline.groovy
def call(int buildNumber) {
if (buildNumber % 2 == 0) {
pipeline {
agent any
stages {
stage('Even Stage') {
steps {
echo "The build number is even"
}
}
}
}
} else {
pipeline {
agent any
stages {
stage('Odd Stage') {
steps {
echo "The build number is odd"
}
}
}
}
}
}
and then aJenkinsfile that uses it (now has 2 lines)
#Library('myCoolLib') _
evenOrOdd(currentBuild.getNumber())
Obviously parameter here is of type int, but it can be any number of parameters of any type.
I use this approach and have one of the groovy scripts that has 3 parameters (2 Strings and an int) and have 15-20 Jenkinsfiles that use that script via shared library and it's perfect. Motivation is of course one of the most basic rules in any programming (not a quote but goes something like): If you have "same code" at 2 different places, something is not right.
There is an option This project is parameterized in your pipeline job configuration. Write variable name and a default value if you wish. In pipeline access this variable with env.variable_name

How to differentiate build triggers in Jenkins Pipeline

I'm hoping to add a conditional stage to my Jenkinsfile that runs depending on how the build was triggered. Currently we are set up such that builds are either triggered by:
changes to our git repo that are picked up on branch indexing
a user manually triggering the build using the 'build now' button in the UI.
Is there any way to run different pipeline steps depending on which of these actions triggered the build?
The following code should works to determine if a user has started the pipeline or a timer/other trigger:
def isStartedByUser = currentBuild.rawBuild.getCause(hudson.model.Cause$UserIdCause) != null
In Jenkins Pipeline without currentBuild.rawBuild access the build causes could be retrieved in the following way:
// started by commit
currentBuild.getBuildCauses('jenkins.branch.BranchEventCause')
// started by timer
currentBuild.getBuildCauses('hudson.triggers.TimerTrigger$TimerTriggerCause')
// started by user
currentBuild.getBuildCauses('hudson.model.Cause$UserIdCause')
You can get a boolean value with:
isTriggeredByTimer = !currentBuild.getBuildCauses('hudson.triggers.TimerTrigger$TimerTriggerCause').isEmpty()
Or, as getBuildCauses() returns an array, the array's size will work correctly with Groovy truthy semantics:
if (currentBuild.getBuildCauses('hudson.triggers.TimerTrigger$TimerTriggerCause')) {
The ability to get causes for a workflow run was released in version 2.22 (2018 Nov 02) to the Pipeline Supporting APIs Plugin. The feature was requested in JENKINS-41272.
A couple methods were added to the currentBuild global variable with that release:
getBuildCauses
Returns a JSON array of build causes for the current build
EXPERIMENTAL - MAY CHANGE getBuildCauses(String causeClass)
Takes a string representing the fully qualified Cause class and returns a JSON array of build causes filtered by that type for the current build, or an empty JSON array if no causes of the specified type apply to the current build
And an example from me submitting:
echo "${currentBuild.buildCauses}" // same as currentBuild.getBuildCauses()
echo "${currentBuild.getBuildCauses('hudson.model.Cause$UserCause')}"
echo "${currentBuild.getBuildCauses('hudson.triggers.TimerTrigger$TimerTriggerCause')}"
And the output:
[Pipeline] echo
[[_class:hudson.model.Cause$UserIdCause, shortDescription:Started by user anonymous, userId:null, userName:anonymous], [_class:org.jenkinsci.plugins.workflow.cps.replay.ReplayCause, shortDescription:Replayed #12]]
[Pipeline] echo
[]
[Pipeline] echo
[]
[Pipeline] End of Pipeline
Finished: SUCCESS
NOTE
There appears to be an issue with the currentBuild.getBuildCauses(type) when the type is a type of Cause contributed by a plugin. For example, currentBuild.getBuildCauses('org.jenkinsci.plugins.workflow.cps.replay.ReplayCause') fails with a java.lang.ClassNotFoundException. This was reported in JENKINS-54673 for the 2.22 version of the Pipeline: Supporting APIs (workflow-support) plugin. It is reportedly fixed in the 2.24 version.
I might be missing something, but you can achieve what you want easily by making use of the when directive:
pipeline {
agent any
stages {
stage('Always') {
steps {
echo "I am always executed"
}
}
stage('ManualTimed') {
steps {
echo "I am only executed when triggered manually or timed"
}
when {
beforeAgent true
anyOf {
triggeredBy 'TimerTrigger'
triggeredBy cause: 'UserIdCause'
}
}
}
stage('GitLabWebHookCause') {
steps {
echo "I am only executed when triggered by SCM push"
}
when {
beforeAgent true
triggeredBy 'GitLabWebHookCause'
}
}
}
}
You will find many similar useful examples for various use cases in the documentation of the when directive.
Edit:
thanks to Jean-Francois Larvoire's answer, I was able to figure out 'my trigger' GitLabWebHookCause I required for my use case.
#vitalii-blagodir:
Your answer works for detecting builds triggered by users and timers, but not by commits.
Instead, I found this to work in my case:
def isTriggeredByIndexing = currentBuild.getBuildCauses('jenkins.branch.BranchIndexingCause').size()
def isTriggeredByCommit = currentBuild.getBuildCauses('com.cloudbees.jenkins.GitHubPushCause').size()
def isTriggeredByUser = currentBuild.getBuildCauses('hudson.model.Cause$UserIdCause').size()
def isTriggeredByTimer = currentBuild.getBuildCauses('hudson.triggers.TimerTrigger$TimerTriggerCause').size()
The .size() suffix returns 0 if the object is missing, or 1 if it's present. This makes the result usable as a boolean.
For finding the object name to use, I found it convenient to display this in the log:
echo "# Build causes"
def buildCauses = currentBuild.buildCauses
def numCause = 0
for (cause in buildCauses) {
echo "${numCause++}: ${cause.shortDescription}" // Display a human-readable index and description
echo "${cause}" // Display the object class name. This allows knowing what names to use in getBuildCauses(name) calls below.
}
Finally, if the goal is to abort a pipeline build in specific cases, then the test must be done before the beginning of the pipeline.
For example, we had a problem with the branch indexing triggering extra useless builds. This was fixed by adding this before the pipeline:
// Avoid useless buils: The branch indexing should only trigger the initial build of a new branch.
def isTriggeredByBranchIndexing = currentBuild.getBuildCauses('jenkins.branch.BranchIndexingCause').size()
if (isTriggeredByBranchIndexing && currentBuild.previousBuild) { // Then it's not the initial build.
echo "# Reindexing a branch already built. It is useless to rebuild it now. Aborting."
currentBuild.result = 'SUCCESS' // Make sure the build is not displayed in red in the Jenkins UI.
return // Abort before the pipeline even starts. (Inside the pipeline, this would only abort one stage.)
}
I think that the answers here are incomplete and do not provide an actual ready to use answer. Here's my code to get it working:
import com.cloudbees.groovy.cps.NonCPS
#NonCPS
def isStartedByTimer() {
def buildCauses = currentBuild.rawBuild.getCauses()
echo buildCauses
boolean isStartedByTimer = false
for (buildCause in buildCauses) {
if ("${buildCause}".contains("hudson.triggers.TimerTrigger\$TimerTriggerCause")) {
isStartedByTimer = true
}
}
echo isStartedByTimer
return isStartedByTimer
}
// [...]
// Other pipeline stuff
script {
isStartedByTimer()
}
When started by user:
00:00:01.353 [hudson.model.Cause$UserIdCause#fa5cb22a]
[Pipeline] echo
00:00:01.358 false
When started by timer:
00:00:01.585 [hudson.triggers.TimerTrigger$TimerTriggerCause#5]
[Pipeline] echo
00:00:01.590 true
Note: the NonCPS decorator is needed because otherwise the next non-script step will throw.
Assuming the two different build causes are "timer" and "push" (to a git repo), you can add the following stage to your Jenkinsfile (in a declarative Jenkins pipeline) to make use of getBuildCauses():
pipeline {
stages {
stage('preparation') {
steps {
script {
// get build cause (time triggered vs. SCM change)
def buildCause = currentBuild.getBuildCauses()[0].shortDescription
echo "Current build was caused by: ${buildCause}\n"
// e.g. "Current build was caused by: Started by GitHub push by mirekphd"
// vs. "Started by timer"
}
}
}
}
}
Then I can decide whether to perform certain stages conditionally (depending on the build cause). For example, pulling a docker base image and inspecting for changes in system libraries (likely security updates) should be done periodically, regardless of whether there was a source code change or not.
We can use "BUILD_CAUSE" variable for getting the information about who initiated the run
for [jenkins-pipeline] you may use
currentBuild.rawBuild.getCauses()
(see github.com/jenkinsci/pipeline-examples/blob/master/… for more details)
There was a similar requirement, where user detail who triggered the build should be there in success / failure notification. The job was already had time based triggered, hence could not use wrap([$class: 'BuildUser']) directly.
I used below step, which print username if the job is triggered manually or timer triggered. So, I used this:
pipeline {
agent any
stages {
stage('Test') {
steps {
script{
env.buildCauses = currentBuild.rawBuild.getCauses()
if (buildCauses.contains("hudson.triggers.TimerTrigger")){
env.builduser = "TimerTrigger"
} else {
wrap([$class: 'BuildUser']) {
env.builduser = "${BUILD_USER}"
}
}
}
echo "Initiated by: ${env.builduser}"
}
}
}
}

How to limit Jenkins concurrent multibranch pipeline builds?

I am looking at limiting the number of concurrent builds to a specific number in Jenkins, leveraging the multibranch pipeline workflow but haven't found any good way to do this in the docs or google.
Some docs say this can be accomplished using concurrency in the stage step of a Jenkinsfile but I've also read elsewhere that that is a deprecated way of doing it.
It looks like there was something released fairly recently for limiting concurrency via Job Properties but I couldn't find documentation for it and I'm having trouble following the code. The only thing I found a PR that shows the following:
properties([concurrentBuilds(false)])
But I am having trouble getting it working.
Does anybody know or have a good example of how to limit the number of concurrent builds for a given, multibranch project? Maybe a Jenkinsfile snippet that shows how to limit or cap the number of multibranch concurrent builds?
Found what I was looking for. You can limit the concurrent builds using the following block in your Jenkinsfile.
node {
// This limits build concurrency to 1 per branch
properties([disableConcurrentBuilds()])
//do stuff
...
}
The same can be achieved with a declarative syntax:
pipeline {
options {
disableConcurrentBuilds()
}
}
Limiting concurrent builds or stages are possible with the Lockable Resources Plugin (GitHub). I always use this mechanism to ensure that no publishing/release step is executed at the same time, while normal stages can be build concurrently.
echo 'Starting'
lock('my-resource-name') {
echo 'Do something here that requires unique access to the resource'
// any other build will wait until the one locking the resource leaves this block
}
echo 'Finish'
As #VadminKotov indicated it is possible to disable concurrentbuilds using jenkins declarative pipelines as well:
pipeline {
agent any
options { disableConcurrentBuilds() }
stages {
stage('Build') {
steps {
echo 'Hello Jenkins Declarative Pipeline'
}
}
}
}
disableConcurrentBuilds
Disallow concurrent executions of the Pipeline. Can be useful for
preventing simultaneous accesses to shared resources, etc. For
example: options { disableConcurrentBuilds() }
Thanks Jazzschmidt, I looking to lock all stages easily, this works for me (source)
pipeline {
agent any
options {
lock('shared_resource_lock')
}
...
...
}
I got the solution for multibranch locking too, with de lockable-resources plugin and the shared-libs here is :
Jenkinsfile :
#Library('my_pipeline_lib#master') _
myLockablePipeline()
myLockablePipeline.groovy :
call(Map config){
def jobIdentifier = env.JOB_NAME.tokenize('/') as String[];
def projectName = jobIdentifier[0];
def repoName = jobIdentifier[1];
def branchName = jobIdentifier[2];
//now you can use either part of the jobIdentifier to lock or
limit the concurrents build
//here I choose to lock any concurrent build for PR but you can choose all
if(branchName.startsWith("PR-")){
lock(projectName+"/"+repoName){
yourTruePipelineFromYourSharedLib(config);
}
}else{
// Others branches can freely concurrently build
yourTruePipelineFromYourSharedLib(config);
}
}
To lock for all branches just do in myLockablePipeline.groovy :
call(Map config){
def jobIdentifier = env.JOB_NAME.tokenize('/') as String[];
def projectName = jobIdentifier[0];
def repoName = jobIdentifier[1];
def branchName = jobIdentifier[2];
lock(projectName+"/"+repoName){
yourTruePipelineFromYourSharedLib(config);
}
}

Set the pipeline name and description from Jenkinsfile

I am trying to do a poc of jenkins pipeline as code. I am using the Github organization folder plugin to scan Github orgs and create jobs per branch. Is there a way to explicitly define the names for the pipeline jobs that get from Jenkinsfile? I also want to add some descriptions for the jobs.
You need to use currentBuild like below. The node part is important
node {
currentBuild.displayName = "$yournamevariable-$another"
currentBuild.description = "$yourdescriptionvariable-$another"
}
Edit: Above one renames build where as Original question is about renaming jobs.
Following script in pipeline will do that(this requires appropriate permissions)
item = Jenkins.instance.getItemByFullName("originalJobName")
item.setDescription("This description was changed by script")
item.save()
item.renameTo("newJobName")
I'm late to the party on this one, but this question forced me in the #jenkins chat where I spent most of my day today. I would like to thank #tang^ from that chat for helping solve this in a graceful way for my situation.
To set the JOB description and JOB display name for a child in a multi-branch DECLARATIVE pipeline use the following steps block in a stage:
steps {
script {
if(currentBuild.rawBuild.project.displayName != 'jobName') {
currentBuild.rawBuild.project.description = 'NEW JOB DESCRIPTION'
currentBuild.rawBuild.project.setDisplayName('NEW JOB DISPLAY NAME')
}
else {
echo 'Name change not required'
}
}
}
This will require that you approve the individual script calls through the Jenkins sandbox approval method, but it was far simpler than anything else I'd found across the web about renaming the actual children of the parent pipeline. The last thing to note is that this should work in a Jenkinsfile where you can use the environment variables to manipulate the job items being set.
I tried to used code snippet from accepted answer to describe my Jenkins pipeline in Jenkinsfile. I had to wrap code snippet into function with #NonCPS annotation and use def for item variable. I have placed code snippet in root of Jenkinsfile, not in node section.
#NonCPS
def setDescription() {
def item = Jenkins.instance.getItemByFullName(env.JOB_NAME)
item.setDescription("Some description.")
item.save()
}
setDescription()

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