How to limit Jenkins concurrent multibranch pipeline builds? - jenkins

Question

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?

Answer 1

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()
}
}

Answer 2

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'

Answer 3

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() }

Answer 4

Thanks Jazzschmidt, I looking to lock all stages easily, this works for me (source)
pipeline {
agent any
options {
lock('shared_resource_lock')
}
...
...
}

Answer 5

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);
}
}