This is a question related to How to make SCM polling work with the Jenkins Workflow plugin. That thread answers how to use SCM polling in a pipeline script once SCM polling is enabled but does not cover how to enable SCM polling.
For example, if you wanted to use the mulit-branch pipeline plugin to create jobs automatically using a Jenkinsfile there is not a way I know of to have the "Poll SCM" option enabled in the job. This makes it difficult to provision on-demand environments such as creating a docker container that has the jobs setup from the beginning. Because you would have to sign-in to Jenkins and go to the configuration and select the "Poll SCM" option once the container was started. Cloudbees offers a template plugin to help solve this problem.
However this is not available to Jenkins using the free version. Is there any workaround or solution for users on the free version of Jenkins?
if you wanted to use the multi-branch pipeline plugin to create jobs automatically using a Jenkinsfile there is not a way I know of to have the "Poll SCM" option enabled in the job
Nor is any needed. Multibranch projects have a configurable polling interval for the branch indexing as a whole, which also serves as a per-branch build trigger, and will also receive webhooks automatically.
To answer the question how to enable SCM polling, you need to do the following.
Using the Pipeline Syntax generator and "properties: Set job properties" you can generate the following which will enable SCM polling.
properties([pipelineTriggers([pollSCM('H * * * *')])])
However as Jesse Glick points out for Multibranch pipelines you don't need to enable SCM polling.
I am thinking about the same problem.
If you are using a online Git service like Github or Bitbucket, I think you could use their Webhooks features to solve it. I have not been able to test the solution yet, but it should work.
In your Multibranch Pipeline configuration, enable the Trigger builds remotely option.
Then you need to enable your Github/Bitbucket Webhook on your repository, using the path (as described in the Jenkins configuration descrition): JENKINS_URL/job/test/build?token=TOKEN_NAME
In order to get my Bitbucket to connect to the web hook, I had to add the following to my declarative pipeline:
pipeline {
stages {
stage('Initialize') {
steps {
//enable remote triggers
script {
properties([pipelineTriggers([pollSCM('')])])
}
//define scm connection for polling
git branch: BRANCH_NAME, credentialsId: 'my-credentials', url: 'ssh://git#stash.server.fqdn/stash/my-project.git'
}
}
}
}
This allows to rebuild a branch, without scanning the entire multibranchiverse. This is especially valuable, when using Bitbucket Project /Github Team-multibranch projects. There a scan can take a few minutes, once you have a few repos/branches.
By directly being able to hook into the branch, you can get a build result much faster, and without any side effects.
NB: In a declarative pipeline the properties call has to be wrapped by a script-block.
Related
I'm trying to set up a scenario where a pull request is created on github that triggers a Jenkins multibranch pipeline, and where that multibranch pipeline uses the Generic Webhook Plugin to extract values from the POST request sent from github to jenkins to be used in the script.
Unfortunately, as described on the Generic Webhook Trigger Plugin wiki:
Note: When configuring from pipeline, that pipeline needs to run once, to apply the plugin trigger config, and after that this plugin will be able to trigger the job. This is how Jenkins works, not something implemented in this plugin. You can avoid this by using Job DSL and have Job DSL create pipeline jobs with the plugin configured in that DSL.
This would be OK using a normal pipeline since it would just be a one off on creation of the Jenkins job. The problem however is that a multibranch pipeline will create a new job whenever a new branch/PR is created, and that means that for each pull request I create on github (which triggers my multibranch pipeline script), I have to then run it twice to get the generic webhook functionality working. Having to resubmit for each PR would be tedious for long-run projects.
It seems to me like there are two possible approaches to solving/improving on this problem. One is to try and play around with DSL Jobs (as suggested by the wiki); but I tried this and couldn't get it to work (it was adding a huge amount of complexity to the set up, so I've abandoned it for now).
The second possible solution is as follows: when a PR is created in github, the Generic Webhook will cause a new job to be created in the multibranch pipeline corresponding to that PR; the first time the multibranch pipeline runs the first build of this newly created job will fail for the reason given in the quote above; but then a solution might involve testing that the first job failed and somehow telling Jenkins to try rebuilding for that job again.
So my question relates to this second approach: how can I most neatly run a rebuild for this multibranch pipeline upon the creation of a PR on github?
Any advice/suggestions would be appreciated!
For triggering multibranch pipline by webhook you can use this plugin:
"Multibranch Scan Webhook Trigger"
https://plugins.jenkins.io/multibranch-scan-webhook-trigger/
Actually that is not true for multibranch pipelines. Just ordinary pipelines needs to run twice.
I updated the docs like:
When configuring from pipeline (not multibranch pipeline)...
I am new to Jenkins. I have development code repository at bitbucket and another test script code repository at bitbucket. Now I have setup a Jenkins job by linking test code repository. Is there any way to trigger a build when code is pushed in develop repo?
I tried many times by pushing change in develop repo, but it does not triggers the jenkins job.
You can configure the Jenkins trigger as an SCM poll.
You will have to enter a cron expression for the polling time period, like:
*/5 * * * *
This means polling from 5 to 5 minutes. If any change is detected, then the build is triggered.
You can add the BitBucket Plugin to your Jenkins instance. It will allow you to configure a webhook in BitBucket that will then trigger any Jenkins job listening for that webhook. The plugin's page has a detailed breakdown, but the basics are;
In your repo in BitBucket, create a new Webhook using your Jenkins' url. I believe the url is generally http://[your jenkins url]/bitbucket-hook/
Make the trigger a repo push.
In your Jenkins job, check the box "Build when a change is pushed to BitBucket" under the Build Triggers section.
Now any time you commit to the repo you created the Webhook on, that Jenkins job will be run.
You can also limit what branches trigger commits by parameterizing your Jenkins build to ignore certain branches / keywords / etc if that's something you need for your specific project.
You can use webhooks to trigger build automatically. There are few options how to use it. See the following articles: this, this and this.
I am currently using Cloudbees Jenkins Coreas my Jenkins solution.
I am using Jenkins Pipelines to write our Jenkins job configuration. These pipelines are stored in GitHub repositories. Each Jenkins job when created is connected to a GitHub Repository where the source code is pulled from, and that's where the Jenkinsfile is stored and Jenkins reads from.
Below are some high-level photos for how our Jenkins jobs are configured.
The advantage of the way these jobs are configured is the Jenkinsfile is always read from the master branch. Meaning if a rouge developer tries to remove stages from the Jenkinsfile from within there own branch, it doesn't matter because the Jenkinsfile is always read from the master branch (which is always protected).
However, the one massive drawback to this - is how do teams and developers who are devops engineerings make changes to the Jenkinsfile? For example, let's say a developer creates a branch called feature-jenkins-search and they edit the Jenkinsfile adding a new stage in the pipeline. Whenever they push these changes to GitHub to test - they can't test as it's always read from the master branch? Meaning devops engineerings have to work directly on the master branch? Surely this is not the best way to go and there is a better configuration to set?
We do want to still provide the security that if a developer is rougue and
You should really look into the Jenkins multi-branch pipeline feature. The Jenkins multi-branch pipeline allows to create a single configuration item in Jenkins (a bit like a folder) that can detect all the branches and pull requests in a GitHub repository with a Jenkinsfile and build them using automatically created jobs. Inside this multi-branch pipeline object when it is configured in Jenkins, you will find a number of jobs to build the various branches and pull-requests in the GitHub repository.
So your developers should maintain a Jenkinsfile in every branch they work on in GitHub to build that branch in your Jenkins server.
It is possible to make the Jenkinsfile do branch specific handling if required with conditional stages / when conditions in the Jenkinsfile pipelines in each branch.
You can lock down the master branch so that code and Jenkinsfile changes from other branches can only be merged with an approved PR (pull request). There is good integration between Jenkins and GitHub such that you can configure the master branch to only allow a PR to be merged if the PR is buildable in Jenkins. So if developers add new stages / processing to a Jenkinsfile on a branch being merged to master, it should be validated so that builds of your master branch are not broken.
There is a lot of configurability in the Jenkins multi-branch pipeline object for detection and handling of branches and it may be necessary to experiment to get it right for what you need with your team. If you cannot find this feature in Jenkins, it is probably because the correct Jenkins pipeline and GitHub related plugins are not installed.
You could also have a look at a similar Jenkins feature called the Jenkins GitHub Organization Folder which allows to detect and build all repos and branches at a GitHub Organization level. But when starting out, I would suggest to look into the multi-branch pipeline at the single repo level first.
These features are discussed in the Jenkins pipeline documentation. We use these features with our internal GitHub and Jenkins server and it works very well.
I think you will find the idea of using a single Jenkinsfile in the master branch to be used for building all branches is unworkable, as you have seen!
Is it possible to trigger Scan Multibranch Pipeline Now action for a Jenkins Multibranch Pipeline from another Job? I have certain issues integrating my old version of Gitlab with Pipeline Jobs in Jenkins and came upon such a workaround.
Alternatively, would it be possible to trigger Scan Multibranch Pipeline Now with a notifyCommit web hook?
The purpose of this would be to Scan Multibranch Pipeline whenever a change occurs in the Git repo, so that new branches are detected after such a change.
Another purpose, which I am unable to achieve otherwise (except for periodic polling per branch which is plain evil to me), is to trigger build of branches affected by given changeset. I use old GitLab (7.8) which does not work with the ordinary Gitlab plugin and the Gitlab Hook plugin does not work with pipeline jobs, so my workaround would be to have an non-Pipeline Job to be triggered by Gitlab Hook plugin and this job would in turn trigger Scan Multibranch Pipeline.
Turned out that simple notifyCommit web hook did the job
I am migrating my old Jenkins free-style job to multi-branch pipeline. I also want to use GitLab hook with them.
My problem is the branch detection. I am doing it manually but I want it to be automatic: when a new branch is pushed to git, GitLab trigger a Jenkins job that trigger the branch detection if the branch parameter from GitLab is not known for Jenkins at the moment. Is this possible to do it or doesn't this exist?
FYI: I tried to launch the multi-branch pipeline job but Jenkins says:
ERROR: No parameterized job named XXX found.
Enable "Build Periodcally" in your multibranch job configuration and the branch indexing will automatically started.
What you really need is a branch source plugin for GitLab with webhook integration, which is tracked as an RFE in JIRA.
Failing that, use a plain Git branch source and configure GitLab to send Jenkins notifications to /git/notifyCommit (IIRC) as documented on the Git plugin wiki. Need specify only a url, no other details. The branch indexing this triggers should both detect new or removed branches, and changes to the head of an existing branch, and schedule builds accordingly.
You can set webhook in GitLab for push events and URL like http://<yourserver>/git/notifyCommit?url=<URL of the Git repository>.
See https://wiki.jenkins-ci.org/display/JENKINS/Git+Plugin#GitPlugin-Pushnotificationfromrepository
GitLab notifies Jenkins on push events which should trigger branch detection also for multibranch pipeline.
I didn't receive the answer I wanted and I ran into this issue today that answered the question :
https://github.com/jenkinsci/gitlab-plugin/issues/298
TLDR: Multi-branch pipeline are not supported yet to be triggered by gitlab commit easily. There is a workaround. Look at the link above.