Jenkins: how to trigger pipeline on git tag - jenkins

We want to use Jenkins to generate releases/deployments on specific project milestones. Is it possible to trigger a Jenkins Pipeline (defined in a Jenkinsfile or Groovy script) when a tag is pushed to a Git repository?
We host a private Gitlab server, so Github solutions are not applicable to our case.

This is currently something that is sorely lacking in the pipeline / multibranch workflow. See a ticket around this here: https://issues.jenkins-ci.org/browse/JENKINS-34395
If you're not opposed to using release branches instead of tags, you might find that to be easier. For example, if you decided that all branches that start with release- are to be treated as "release branches", you can go...
if( env.BRANCH_NAME.startsWith("release-") ) {
// groovy code on release goes here
}
And if you need to use the name that comes after release-, such as release-10.1 turning into 10.1, just create a variable like so...
if( env.BRANCH_NAME.startsWith("release-") ) {
def releaseName = env.BRANCH_NAME.drop(8)
}
Both of these will probably require some method whitelisting in order to be functional.

I had the same desire and rolled my own, maybe not pretty but it worked...
In your pipeline job, mark that "This project is parameterized" and add a parameter for your tag. Then in the pipeline script checkout the tag if it is present.
Create a freestyle job that runs a script to:
Checkout
Run git describe --tags --abbrev=0 to get the latest tag.
Check that tag against a running list of builds (like in a file).
If the build hasn't occurred, trigger the pipeline job via a url passing your tag as a parameter (in your pipeline job under "Build Triggers" set "Trigger builds remotely (e.g. from scripts) and it will show the correct url.
Add the tag to your running list of builds so it doesn't get triggered again.
Have this job run frequently.

if you use multibranch pipeline, there is a discover tag. Use that plus Spencer solution

Related

Jenkins: Access job/plugin configuration values inside pipeline

I am trying the access the values set on a job's configuration page from within my pipeline. These values are not made available as params, nor are they injected as envvars.
Setup
Jenkins, v2.263.1
GitLab Branch Source plugin, v1.5.3 (link)
Multibranch pipeline job which is pointed to a Gitlab repo
Remote Jenkinsfile Provider, v1.13 (link)
Problem
Ordinarily, one would have a Jenkinsfile in the root of the repo and therefore the scm would be associated with the repo we want to checkout and build. However, in my case the code I want to build is in a different repo to the Jenkinsfile (hence the Remote Jenkinsfile Provider plugin).
This means that I need to checkout the code I wish to build as an explicit step in the pipeline, and to do that I need to know the repo. This repo is, however, already defined in the job config.
The Branch Source plugin does export things like the branch name or merge request number/branch/target into appropriate envvars, but NOT the actual repo.
As this is a multibranch pipeline, I cannot use something like envInject either (multibranch jobs do not provide the option to 'Prepare an environment for the run' as with other jobs)
Goal
I would like to be able to access the server, owner and project fields set in the job config page. Ultimately I could manage with just the project's ssh/http address even.
Is there some clever way of accessing a job's config from within the pipeline?
Thanks for any suggestions!
Reference images
Within the gitlab branch source plugin (and the documentation) you have a lot more information, than just with the normal branch source plugin. there are environment variables for the project like GITLAB_PROJECT_GIT_SSH_URL/GITLAB_PROJECT_GIT_HTTPS_URL for the git source and many more. So far i did not see one for the server, but that would be parse-able our of the URLs.
Within this information, it should be fairly easy to checkout the repository and build it.
As through the process it came clear, that it is needed to also trigger the pipeline manually, and this is normally also possible with variables (not sure about the Remote File plugin). I assume your Jenkinsfile is a groovy script, which opens up a lot of possibilities. You can define variables and use some logic to determine if the env variable or the parameter is used.
pipeline {
parameters {
string(name: 'projectUrl', defaultValue: "")
}
stages {
stage('Prepare') {
steps {
def projectUrl = env.GITLAB_PROJECT_GIT_SSH_URL ?: params.projectUrl
// DO Checkout with projectUrl
}
}
}
}
The only critical thing you have to take into account, is that the multibranch pipeline, has to run once, for each branch or mr - so they detect the variables. Afterwards you can easily trigger it, manually by providing your values.
This allows you, to utilize webhooks for automatic actions, and also allows you to trigger the build manually when ever you like.
Sidenote: if you use the centralized jenkinsfile, for reducing duplication, you might also want to checkout Shared libraries for jenkins.
For completeness, here is a list of all current environment variables added by the jenkins gitlab branch source plugin version 1.5.3 (and only for Push Events - but they are pretty similar in the other event types too)
GITLAB_OBJECT_KIND
GITLAB_AFTER
GITLAB_BEFORE
GITLAB_REF
GITLAB_CHECKOUT_SHA
GITLAB_USER_ID
GITLAB_USER_NAME
GITLAB_USER_EMAIL
GITLAB_PROJECT_ID
GITLAB_PROJECT_ID_2
GITLAB_PROJECT_NAME
GITLAB_PROJECT_DESCRIPTION
GITLAB_PROJECT_WEB_URL
GITLAB_PROJECT_AVATAR_URL
GITLAB_PROJECT_GIT_SSH_URL
GITLAB_PROJECT_GIT_HTTP_URL
GITLAB_PROJECT_NAMESPACE
GITLAB_PROJECT_VISIBILITY_LEVEL
GITLAB_PROJECT_PATH_NAMESPACE
GITLAB_PROJECT_CI_CONFIG_PATH
GITLAB_PROJECT_DEFAULT_BRANCH
GITLAB_PROJECT_HOMEPAGE
GITLAB_PROJECT_URL
GITLAB_PROJECT_SSH_URL
GITLAB_PROJECT_HTTP_URL
GITLAB_REPO_NAME
GITLAB_REPO_URL
GITLAB_REPO_DESCRIPTION
GITLAB_REPO_HOMEPAGE
GITLAB_REPO_GIT_SSH_URL
GITLAB_REPO_GIT_HTTP_URL
GITLAB_REPO_VISIBILITY_LEVEL
GITLAB_COMMIT_COUNT
GITLAB_COMMIT_ID_#
GITLAB_COMMIT_MESSAGE_#
GITLAB_COMMIT_TIMESTAMP_#
GITLAB_COMMIT_URL_#
GITLAB_COMMIT_AUTHOR_AVATAR_URL_#
GITLAB_COMMIT_AUTHOR_CREATED_AT_#
GITLAB_COMMIT_AUTHOR_EMAIL_#
GITLAB_COMMIT_AUTHOR_ID_#
GITLAB_COMMIT_AUTHOR_NAME_#
GITLAB_COMMIT_AUTHOR_STATE_#
GITLAB_COMMIT_AUTHOR_USERNAME_#
GITLAB_COMMIT_AUTHOR_WEB_URL_#
GITLAB_COMMIT_ADDED_#
GITLAB_COMMIT_MODIFIED_#
GITLAB_COMMIT_REMOVED_#
GITLAB_REQUEST_URL
GITLAB_REQUEST_STRING
GITLAB_REQUEST_TOKEN
GITLAB_REFS_HEAD

Notifications on jenkins job failures - with pipeline from scm

We have several jenkins pipeline jobs setup as "pipeline from scm" that checkout a jenkins file from github and runs it. There is sufficient try/catch based error handling inside the jenkinsfile to trap error conditions and notify the right channels.This blog post goes into a quite a bit of depth about how to achieve this.
However, if there is issue fetching the jenkinsfile in the first place, the job fails silently. How does one generate notifications from general job launch failures before the pipeline is even started?
Jenkins SCM pipeline doesn't have any execution provision similar to catch/finally that will be called if Jenkinsfile load is failed, And I don't think there will be any in future.
However there is this global-post-script which runs groovy script after every build of every job on Jenkins. You have to place that script in $JENKINS_HOME/global-post-script/ directory.
Using this you can send notifications or email to admins based on project that failed and/or reason/exceptions of failure.
Sample code that you can put in script
if ("$BUILD_RESULT" != 'SUCCESS') {
def job = hudson.model.Hudson.instance.getItem("$JOB_NAME")
def build = job.getBuild("$BUILD_NUMBER")
def exceptionsToHandle = ["java.io.FileNotFoundException","hudson.plugins.git.GitException"]
def foundExection = build
.getLog()
.split('\n')
.toList()
.stream()
.filter{ line ->
!line.trim().isEmpty() && !exceptionsToHandle.stream().filter{ex -> line.contains(ex)}.collect().isEmpty()
}
.collect()
.size() > 0;
println "do something with '$foundExection'"
}
You can validate your Jenkinsfile before pushing it to repository.
Command-line Pipeline Linter
There are some IDE Integrations as well
Apparently this is an open issue with Jenkins: https://issues.jenkins.io/browse/JENKINS-57946
I have decided not to use Yogesh answer mentioned earlier. For me it is simpler to just copy the content of the Jenkinsfile directly into the Jenkins project instead of pointing Jenkins to the GIT location of the Jenkinsfile. However, in addition I keep the Jenkinsfile in GIT. But make sure to keep the GIT and the Jenkins version identical.

Jenkins multibranch pipeline only for subfolder

I have git monorepo with different apps. Currently I have single Jenkinsfile in root folder that contains pipeline for app alls. It is very time consuming to execute full pipeline for all apps when commit changed only one app.
We use GitFlow-like approach to branching so Multibranch Pipeline jobs in Jenkins as perfect fit for our project.
I'm looking for a way to have several jobs in Jenkins, each one will be triggered only when code of appropriate application was changed.
Perfect solution for me looks like this:
I have several Multibranch Pipeline jobs in Jenkins. Each one looks for changes only to given directory and subdirectories. Each one uses own Jenkinsfile. Jobs pull git every X minutes and if there are changes to appropriate directories in existing branches - initiates build; if there are new branches with changes to appropriate directories - initiates build.
What stops me from this implementation
I'm missing a way to define commit to which folders must be ignored during scan execution by Multibranch pipeline. "Additional behaviour" for Multibranch pipeline doesn't have "Polling ignores commits to certain paths" option, while Pipeline or Freestyle jobs have. But I want to use Multibranch pipeline.
Solution described here doesnt work for me because if there will be new branch with changes only to "project1" then whenever Multibranch pipeline for "project2" will be triggered it will discover this new branch anyway and build it. Means for every new branch each of my Multibranch pipelines will be executed at least once no matter if there was changes to appropriate code or not.
Appreciate any help or suggestions how I can implement few Multibranch pipelines watching over same git repository but triggered only when appropriate pieces of code changed
This can be accomplished by using the Multibranch build strategy extension plugin. With this plugin, you can define a rule where the build only initiates when the changes belong to a sub-directory.
Install the plugin
On the Multibranch pipeline configuration, add a Build strategy
Select Build included regions strategy
Put a sub-folder on the field, such as subfolder/**
This way the changes will still be discovered, but they won't initiate a build if it doesn't belong to a certain set of files or folders.
This is the best approach I'm aware so far. But I think the best way would be a case where the changes doesn't even get discovered.
Edit: Gerrit Code Review plugin configuration
In case you're using the Gerrit Code Review plugin, you can also prevent new changes to be discovered by using a custom query:
I solved this by creating a project that builds other projects depending on the files changed. For example, from your repo root:
/Jenkinsfile
#!/usr/bin/env groovy
pipeline {
agent any
options {
timestamps()
}
triggers {
bitbucketPush()
}
stages {
stage('Build project A') {
when {
changeset "project-a/**"
}
steps {
build 'project-a'
}
}
stage('Build project B') {
when {
changeset "project-b/**"
}
steps {
build 'project-b'
}
}
}
}
You would then have other Pipeline projects with their own Jenkinsfile (i.e., project-a/Jenkinsfile).
I know that this post is quite old, but I solved this problem by changing the "include branches" parameter for SVN repositories (this can possibly also be done using the property "Filter by name (with wildcards)" for git repos). Instead of supplying only the actual branch name, I also included the subfolder. So instead of only supplying "trunk", I used "trunk/subfolder". This limits scanning to only that specific directory. Note that I have not yet fully tested this solution.

Jenkins multibranch pipeline with Jenkinsfile from different repository

I have a Git repository with code I'd like to build but I'm not "allowed" to add a Jenkinsfile in its root (it is a Debian package so I can't add files to upstream source). Is there a way to store the Jenkinsfile in one repository and have it build code from another repository? Since my code repository has several branches to build (one for each Debian release) this should be a multibranch pipeline. Commits in either the code or Jenkinsfile repositories should trigger a build.
Bonus complexity: I have several code/packaging repositories like this and I'd like to reuse the same Jenkinsfile for all of them. Thus it should somehow dynamically fetch the right Git URL to use. The branches to build have the same names across all repositories.
Short answer is : you cannot do that with a multibranch pipeline. Multibranch pipelines are only designed (at least for now) to execute a specific pipeline in Pipeline script from SCM style, with a fixed Jenkinsfile at the root of the project.
You can however use the Multi-Branch Project plugin made for multibranch freestyle projects. First, you need to define your multibranch freestyle configuration just like you would with a multibranch pipeline configuration.
Select this new item like shown below :
This type of configuration will behave exactly same as the multibranch pipeline type, i.e. it will create you a folder with the name of your configuration and a sub-project for each branch it automatically detected.
The implementation should then be a piece of cake :
Specify your SCM repository in the multibranch configuration
Call another build as part of your build/post-build as you would do in a standard freestyle project, except that you have to call a parameterized job (let's call it build-job) and give it your repository information, i.e. Git URL and current branch (you can use the pre-defined variables $GIT_URL and $GIT_BRANCH for this purpose)
In your build-job, just define either an inline pipeline or a pipeline script checked out from SCM, and inside this script do a SCM checkout and go on with the steps you need to build. Example of build-job pipeline content :
.
node() {
stage 'Checkout'
checkout scm: [$class: 'GitSCM', branches: [[name: '*/${GIT_BRANCH}']], userRemoteConfigs: [[url: '${GIT_URL}']]]
stage 'Build'
// Build steps...
}
Of course if your different multibranches projects need to be treated a bit differently, you could also use intermediate projects (let's say build-project-A, build-project-B, ...) that would in turn call the generic build-job pipeline)
The one, major drawback of this solution is that you will only have one job responsible for all of your builds, making it harder to debug. You would still have your multibranch projects going blue/red in case of success/error but you will have to go back to called build-job to find the real problem of your build.
The best way I have found is to use the Remote Jenkinsfile Provider plugin. https://plugins.jenkins.io/remote-file/
This will add an option "by Remote Jenkinsfile Provider plugin" under Build Configuration>Mode then you can point to another repo where the Jenkinsfile is. I find this to be a much better solution than the Pipeline Multibranch Defaults Plugin, which makes you store the Jenkins file in Jenkins itself, rather than in source control.
U can make use of this plugin
https://github.com/jenkinsci/pipeline-multibranch-defaults-plugin/blob/master/README.md
Where we need to configure the jenkinsfile on jenkins rather than having it on each branch of your repo
I have version 2.121 and you can do this two ways:
Way 1
In the multibranch pipeline configuration > Build Configuration > Mode > Select "Custom Script" and put in "Marker File" below the name of a file you will use to identify branches that you want to have builds for.
Then, below that in Pipeline > Definition select "Pipeline Script from SCM" and enter the "SCM" information for how to find the "Jenkinsfile" that holds the script you want to run. It can be in the same repo you are finding branches in to create the jobs (if you put in the same GitHub repo's info) but I can't find a way to indicate that you just use the same branch for the file.
Way 2
Same as above, in the multibranch pipeline configuration > Build Configuration > Mode > Select "Custom Script" and put in "Marker File" below the name of a file you will use to identify branches that you want to have builds for.
Then, below that in Pipeline > Definition select "Pipeline Script" and put a bit of Groovy in the text box to load whatever you want or to run some script that already got loaded into the workspace.
In my case, i have an escenario whith a gitlab project based on gradle who has dependencies on another gitlab preject based on gradle too (same dashboard, but differents commits, differents developers).
I have added the following lines into my Jenkinsfile (the one which depends)
stage('Build') {
steps {
git branch: 'dev', credentialsId: 'jenkins-generated-ssh-key', url: 'git#gitlab.project.com:root/coreProject.git'
sh './gradlew clean'
}
}
Note: Be awark on the order on the sentences.
If you have doubt on how to create jenkins-generated-ssh-key please ask me

Jenkins workflow job: Use parameter as branch specifier

I want to migrate our old free style dev builds, in which we use the branch name as a build parameter, to workflow builds.
This works fine so far, the only thing we are really missing is the ability to use the parameter, e.g. "branch_name", as the branch specifier for the Workflow script from SCM section.
On a free style build this works fine.
Any ideas how this could be achieved? We don't want a dev to change the configuration all the time before starting a build.
Try to disable "Lightweight checkout" checkbox.
This behavior is noted when clicking the help question mark for the "Lightweight checkout" option:
Also build parameters will not be substituted into SCM configuration in this mode.
Found that in latest comments of JENKINS-28447
Sounds like JENKINS-28447:
When selecting the "Groovy CPS DSL from SCM" option for a worflow job,
the SCM plugins do not appear to resolve build parameters or
environment variables. I am using the git plugin and when I use it
from other jobs I can specify a build parameter, like "BuildBranch",
and use that when specifying what branch should be built
The workaround would be to use an inline bootstrap script that calls load after checkout, as described in the tutorial.
Alternately, go further by creating a multibranch workflow project, so that each branch is built automatically with its own history.
I have a workflow DSL script described here: https://groups.google.com/forum/#!msg/jenkinsci-users/jSKwSKbaXq8/dG2mn6iyDQAJ
In that script, I have a build parameter called FREEBSD_SRC_URL , which is
passed down to the workflow. Based on different parameters in that URL,
a different branch can be checked out.
If you are using git, you can still use the same technique for passing a build parameter down to the script, but you would need to do things slightly differently. For example, you could define a parameter BRANCH_NAME in your job and do something like this in your workflow script:
String checkout_url = "https://github.com/jenkinsci/jenkins"
String branch_name = "master"
if (getBinding().hasVariable("CHECKOUT_URL")) {
// override default URL from build parameter
checkout_url = CHECKOUT_URL
}
if (getBinding().hasVariable("BRANCH_NAME")) {
// override default branch from build parameter
branch_name = BRANCH_NAME
}
node {
// Do the git checkout
git branch: "${branch_name}", url: "${checkout_url}"
}

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