conditional branch in groovy code based on state - jenkins

I have a webhook in gitlab, that triggers a Jenkins job which run a groovy script.
Now I want that the branch to checkout will be conditional:
If the state is merged to take the target_branch and if not that the source_branch
I couldn't find exactly how to do it in the groovy code. The triggers are different for one is note and for the other is merge request

There are gitlab variables that are passed: https://github.com/jenkinsci/gitlab-plugin#defined-variables
so the following solved my issue:
// Distniguish between 2 types of webhook triggers
if(env.gitlabMergeRequestState != null) {
merge_status = "merged"
if (merge_status.equalsIgnoreCase(env.gitlabMergeRequestState)) {
echo "Merged Trigger, using: ${env.gitlabTargetBranch} branch"
branch = env.gitlabTargetBranch
} else {
echo "Note Trigger, using: ${env.gitlabSourceBranch} branch"
branch = env.gitlabSourceBranch
}
}

Related

Jenkins pipeline with a conditional trigger

My Jenkins pipeline is as follow:
pipeline {
triggers {
cron('H */5 * * *')
}
stages {
stage('Foo') {
...
}
}
}
The repository is part of a Github Organization on Jenkins - every branch or PR pushed results in a Jenkins job being created for that branch or PR.
I would like the trigger to only be run on the "main" branch because we don't need all branches and PRs to be run on a cron schedule; we only need them to be run on new commits which they already do.
Is it possible?
yes - it's possible. To schedule cron trigger only for a specific branch you can do it like this in your Jenkinsfile:
String cron_string = (scm.branches[0].name == "main") ? 'H */5 * * *' : ''
pipeline {
triggers {
cron(cron_string)
}
// whatever other code, options, stages etc. is in your pipeline ...
}
What it does:
Initialize a variable based on a branch name. For main branch it sets requested cron configuration, otherwise there's no scheduling (empty string is set).
Use this variable within pipeline
Further comments:
it's possible to use it also with parameterizedCron (in a case you'd want / need to).
you can use also some other variables for getting branch name, e.g: env.BRANCH_NAME instead of scm.branches[0].name. Whatever fits your needs...
This topic and solution is discussed also in Jenkins community: https://issues.jenkins.io/browse/JENKINS-42643?focusedCommentId=293221#comment-293221
EDIT: actually a similar question that leads to the same configuration - here on Stack: "Build Periodically" with a Multi-branch Pipeline in Jenkins
You can simply add a when condition to your pipeline.
when { branch 'main' }

Jenkins Git-Push with master branch only

This might be a very basic question in terms of jenkins and github integration. However, I am thinking good to ask.
What I am basically looking to do is if anything pushed to master branch of git only then my jenkins job must get triggered. Considering there are multiple feature branches and multiple commits happening on different branches but I am interested only in master branch push.
I did not find good documentation over, could anybody give me any pointer on this.
Help is appreciated, thanks!
OK, so you got two options:
Create a single branch pipeline
Just click on create new item, select pipeline and under "Pipeline" configure as "Pipeline script from SCM" and put your GitHub and in "branches to build" put "*/master".
Add brach conditions
Alternatively you could add when conditions to your stages if you use declarative syntax:
pipeline {
agent any
stages {
stage("Build") {
when { branch 'master' }
steps {
// do your build
}
}
}
}
Or if you're using scripted:
node {
stage('Build') {
if (env.BRANCH_NAME == 'master') {
// do your build
}
}
}
See "flow control".

Jenkins - how to show downstream jobs build result on Gerrit patch set?

below is my use case,
I have jobs A, B, C - A is upstream and B and C are downstream jobs. When a Patch set created in Gerrit, based on the patchset created event I trigger Job A and based on the result of this job, we trigger B and C. After the B and C is executed, I want to display the result of all three jobs on Gerrit patch set. like
Job A SUCCESS
JOB B SUCCESS
JOB C FAILED
right now I see only JOB A Build result showing up on GERRIT PATCH SET as
JOB A SUCCESS
is there any way to do this?
Do the following:
1) Configure all jobs (A, B and C) to trigger when the patch set is created.
2) Configure the jobs B and C to depend on job A
2.1) Click on "Advanced..." in Gerrit Trigger job configuration
2.2) Add the job A on the "Other jobs on which this job depends" field
With this configuration jobs B and C will wait for job A finish before they start and you'll get the result you want:
The best way to solve this is to create a small wrapper pipeline job. Let name it Build_ABC.
Configure Build_ABC to trigger on the Gerrit event you wish. The job will be responsible for running the other 3 builds and in the event of any failures in these jobs your Build_ABC will fail and report this back to Gerrit. You will not be able to see immediately which job failed in your Gerrit message but you will be able to see in in your Jenkins pipeline overview.
In the below scripted pipeline script you see a pipeline that calls Build_A and waits for the result. If the build succeeds it will continue to execute Build B and C in parallel. In my example I made Build C failed which caused the whole pipeline job to fail.
This is a revised version of my fist answer and the script has grown a bit. As it is required to have the individual build results in the message posted to Gerrit the pipeline has been changed to catch the individual results and record them. If build A fails builds B+C will be skipped and the status will be skipped.
Next it is possible to use the gerrit review ssh command line tool to perform manual review. This way it is possible to have a custom message generated to include the individual build results. It looks like the screen shot below:
I haven't figured out how to make it a multi line comment but there is also an option to use json in the command line, have a look at that.
def build_a = "Skipped"
def build_b = "Skipped"
def build_c = "Skipped"
def build_result = "+1"
try {
stage("A") {
try {
build( job: '/Peter/Build_A', wait: true)
build_a = "Pass"
} catch (e) {
build_a = "Failed"
// throw again or else the job to make the build fail
// throwing here will prevent B+C from running
throw e
}
}
stage("After A") {
parallel B: {
try {
build( job: '/Peter/Build_B', wait: true)
build_b = "Pass"
} catch (e) {
build_b = "Failed"
// throw again or else the job to make the build fail
throw e
}
}, C: {
try {
build( job: '/Peter/Build_C', wait: true)
build_c = "Pass"
} catch (e) {
build_c = "Failed"
// throw again or else the job to make the build fail
throw e
}
}
}
} catch(e) {
build_result = "-1"
// throw again or else the job to make the build fail
throw e
} finally {
node('master') {
// Perform a custom review using the environment vars
sh "ssh -p ${env.GERRIT_PORT} ${env.GERRIT_HOST} gerrit review --verified ${build_result} -m '\"Build A:${build_a} Build B: ${build_a} Build C: ${build_c}\"' ${env.GERRIT_PATCHSET_REVISION}"
}
}
Next you should configure the Gerrit trigger to ignore the results from Jenkins or else there will be a double vote.
One more advantage is that with the Ocean Blue plugin you can get a nice graphical representation, see below image, of your build and you can examine what went wrong by clicking on the jobs.

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 disable automatic build from scm change in Jenkinsfile

I have a Jenkinsfile that I've set up with a cron for a pipelineTriggers parameter. I can't seem to figure out how to disable the job from building from a merge to the master branch of the repo. Is there a way in the Jenkinsfile to disable the automatic build from an scm change?
If you're using a Multibranch Pipeline, you should be able to do this on the job's Configure page:
Scroll down to "Branch Sources"
Under "Property strategy", choose "Named branches get different properties"
Click "Add exception", enter "master" as the branch name
Click "Add property", choose "Suppress automatic SCM triggering"
Save
That would prevent changes to the master branch from triggering a build of the corresponding job.
For declarative pipelines, use the when directive with a triggeredBy condition, e.g.
when { triggeredBy 'TimerTrigger' }
With the multibranch pipeline, I could not figure out a way to prevent the next build being triggered. As a workaround, I added the following code to my Jenkinsfile (using scripted syntax), to abort the following build if the only changes contain "[ci-skip]" in the commit message:
def abortBuildIfTriggeredBySkippableCommit() {
def changeSetCount = 0;
def ciSkipCount = 0;
if (currentBuild.changeSets != null) {
for (changeSetList in currentBuild.changeSets) {
for (changeSet in changeSetList) {
changeSetCount++;
if (changeSet.msg.contains('[ci-skip]')) {
ciSkipCount++;
}
}
}
}
if (changeSetCount > 0 && changeSetCount == ciSkipCount) {
currentBuild.result = 'NOT_BUILT'
error("Stopping to prevent auto trigger. All commits contained [ci-skip]")
}
}
Note that this code assumes you are using the git plugin, and that the objects in currentBuild.changeSets will be GitChangeSetList.
In a jenkins job you can navigate to advanced source code management
Select behavior Dont trigger build on commit notification
This disables the Started by an SCM change
For people still looking for a solution, go to configuration for the multi branch pipeline, under Property Strategy, choose "Suppress Automatic SCM Triggering".
Note: This is available on cloudbees version of Jenkins. I am not sure, if it matters.
https://support.cloudbees.com/hc/en-us/articles/360026953651-Preventing-builds-from-getting-triggered-when-creating-a-new-multibranch-Pipeline-or-Organization-Folder?page=29
This is what I came up with. I was hoping for something less messy, but this does seem to work:
I have this as the build's properties:
properties([
pipelineTriggers([cron('H H 7 * *')])
])
I then have this function that defines the source of the build:
// check if the job was started by a timer
#NonCPS
def jobStartedByWhat() {
def startedByWhat = ''
try {
def buildCauses = currentBuild.rawBuild.getCauses()
for ( buildCause in buildCauses ) {
if (buildCause != null) {
def causeDescription = buildCause.getShortDescription()
echo "shortDescription: ${causeDescription}"
if (causeDescription.contains("Started by timer")) {
startedByWhat = 'timer'
}
if (causeDescription.contains("Started by user")) {
startedByWhat = 'user'
}
}
}
} catch(theError) {
echo "Error getting build cause: ${theError}"
}
return startedByWhat
}
def startedByWhat = jobStartedByWhat()
I can then evaluate the function at runtime so that if a build gets triggered because of a merge to master, it will not actually run:
node {
try {
checkout scm
if (env.BRANCH_NAME == 'master') {
if (startedByWhat == 'timer' || startedByWhat == 'user') {
..... RUN THE BUILD .....
} else {
.... EXIT WITHOUT RUNNING THE BUILD ....
I stumbled upon this as well. IMO an acceptable solution would be a filter for commit messages when checking out source code - this feature exists for regular Jobs but is missing for multibranch pipelines, see https://issues.jenkins-ci.org/browse/JENKINS-48296.
For those not using the git plugin, this method is a workaround for scripted pipelines (inspired by scarswell's answer):
def abortBuildIfTriggeredBySkippableCommit() {
lastCommitMessage = sh(
script: "${gitBinary} --no-pager log -1 --pretty=%B",
returnStdout: true
)
if (lastCommitMessage != null &&
lastCommitMessage.toString().contains('[maven-release-plugin]')) {
currentBuild.result = 'ABORTED'
error("Stopping build, it was triggered by the maven release plugin")
}
}
For declarative pipelines, there is a much more simple answer now. From the docs:
overrideIndexTriggers
Allows overriding default treatment of branch indexing triggers. If branch indexing triggers are disabled at the multibranch or organization label, options { overrideIndexTriggers(true) } will enable them for this job only. Otherwise, options { overrideIndexTriggers(false) } will disable branch indexing triggers for this job only.
It's a little backwards conceptually, but assuming your jobs are triggering off github webhooks by default, you set overrideIndexTriggers(false) to disable the automatic triggering.
If you are using Pipeline script from SCM then comment out the triggers section(either SCMPoll/BuildPeriodically option ) in Jenkins file as shown below.
//triggers {cron ('H/15 * * * *')}
//pipelineTriggers([pollSCM('H/15 * * * *')])
If you are using Pipeline script then disable the PollSCM/Build periodically(whichever is used) option.
One could disable the scm build trigger by disabling the webhook notification from git.
if (currentBuild.getBuildCauses().toString().contains('BranchIndexingCause') || currentBuild.getBuildCauses().toString().contains('Branch event')) {
print "INFO: Build skipped due to trigger being Branch Indexing"
currentBuild.result = 'ABORTED' // optional, gives a better hint to the user that it's been skipped, rather than the default which shows it's successful
return
}
timestamps{
node
{
stage('Getting Build Parameters')
{
print('build job')
}
}
}
if (currentBuild.getBuildCauses().toString().contains('BranchIndexingCause') || currentBuild.getBuildCauses().toString().contains('Branch event')) {
print "INFO: Build skipped due to trigger being Branch Indexing"
currentBuild.result = 'ABORTED' // optional, gives a better hint to the user that it's been skipped, rather than the default which shows it's successful
return
}
if (currentBuild.getBuildCauses().toString().contains('BranchIndexingCause') || currentBuild.getBuildCauses().toString().contains('Branch event')) {
print "INFO: Build skipped due to trigger being Branch Indexing"
currentBuild.result = 'ABORTED' // optional, gives a better hint to the user that it's been skipped, rather than the default which shows it's successful
return
}

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