How do I dynamically trigger downstream builds in jenkins?

Question

We want to dynamically trigger integration tests in different downstream builds in jenkins. We have a parametrized integration test project that takes a test name as a parameter. We dynamically determine our test names from the git repo.

We have a parent project that uses jenkins-cli to start a build of the integration project for each test found in the source code. The parent project and integration project are related via matching fingerprints.

The problem with this approach is that the aggregate test results doesn't work. I think the problem is that the "downstream" integration tests are started via jenkins-cli, so jenkins doesn't realize they are downstream.

I've looked at many jenkins plugins to try to get this working. The Join and Parameterized Trigger plugins don't help because they expect a static list of projects to build. The parameter factories available for Parameterized Trigger won't work either because there's no factory to create an arbitrary list of parameters. The Log Trigger plugin won't work.

The Groovy Postbuild Plugin looks like it should work, but I couldn't figure out how to trigger a build from it.

Answer 1

def job = hudson.model.Hudson.instance.getJob("job")
def params = new StringParameterValue('PARAMTEST', "somestring")  
def paramsAction = new ParametersAction(params) 
def cause = new hudson.model.Cause.UpstreamCause(currentBuild)
def causeAction = new hudson.model.CauseAction(cause) 
hudson.model.Hudson.instance.queue.schedule(job, 0, causeAction, paramsAction) 

This is what finally worked for me.

Answer 2

NOTE: The Pipeline Plugin should render this question moot, but I haven't had a chance to update our infrastructure.

To start a downstream job without parameters:

job = manager.hudson.getItem(name)
cause = new hudson.model.Cause.UpstreamCause(manager.build)
causeAction = new hudson.model.CauseAction(cause)
manager.hudson.queue.schedule(job, 0, causeAction)

To start a downstream job with parameters, you have to add a ParametersAction. Suppose Job1 has parameters A and C which default to "B" and "D" respectively. I.e.:

A == "B"
C == "D"

Suppose Job2 has the same A and B parameters, but also takes parameter E which defaults to "F". The following post build script in Job1 will copy its A and C parameters and set parameter E to the concatenation of A's and C's values:

params = []
val = ''
manager.build.properties.actions.each {
    if (it instanceof hudson.model.ParametersAction) {
        it.parameters.each {
            value = it.createVariableResolver(manager.build).resolve(it.name)
            params += it
            val += value
        }
    }
}

params += new hudson.model.StringParameterValue('E', val)
paramsAction = new hudson.model.ParametersAction(params)

jobName = 'Job2'
job = manager.hudson.getItem(jobName)
cause = new hudson.model.Cause.UpstreamCause(manager.build)
causeAction = new hudson.model.CauseAction(cause)
def waitingItem = manager.hudson.queue.schedule(job, 0, causeAction, paramsAction)
def childFuture = waitingItem.getFuture()
def childBuild = childFuture.get()

hudson.plugins.parameterizedtrigger.BuildInfoExporterAction.addBuildInfoExporterAction(
    manager.build, childProjectName, childBuild.number, childBuild.result
)

You have to add $JENKINS_HOME/plugins/parameterized-trigger/WEB-INF/classes to the Groovy Postbuild plugin's Additional groovy classpath.