How to run downstream job conditionally based on a parameter in Jenkins pipeline?

Question

Following on from my question How to trigger parameterized build on successful build in Jenkins?

I would like the invoke a downstream project but only if a boolean parameter is set to true. Is this possible? My pipeline looks like this:

node {
    try {
        echo "ConfigFilePath: ${ConfigFilePath}"
        echo "Delete VM on Successful Build: ${DeleteOnSuccess}"

        stage('checkout') {
            deleteDir()
            git 'http://my.git.lab/repo.git'
        }   

        stage('deploy') {
                bat 'powershell -nologo -file BuildMyVM.ps1 -ConfigFilePath "%ConfigFilePath%" -Verbose'                
            }
        }
        stage('test') {
            // functional tests go here
        }    
    } 
    catch (e) {
    // exception code

  } finally {
    // finally code

  }
} //node

stage('delete') {
    if(DeleteOnSuccess)
    {
        bat 'SET /p VM_NAME=<DeleteVM.txt'
        echo "Deleting VM_NAME: %VM_NAME%"
        def job = build job: 'remove-vm', parameters: [[$class: 'StringParameterValue', name: 'VM_NAME', value: '${VM_NAME}']]
    }
}

I get this error on the delete stage

Required context class hudson.FilePath is missing. Perhaps you forgot to surround the code with a step that provides this, such as: node

If I wrap the above in a node, then the parameter values are lost. If I put the delete stage in the main node, then I take up two executors, which I'm trying to avoid because it will result in some deadlock conditions.

The error you get is about the bat you are trying to run. This requires a node (or actually a environment) as well. So depending on how you invoke your build in the first place, you need to surround that with node {...} as wel, or just put it inside the node block as well. If you only want to trigger it, and not wait for the build, you can add wait: false to the build command. — Rik
OK, if I remove the bat and the echo lines, the job in the delete stage executes whether the project parameter DeleteOnSuccess is set to true or false. Any ideas why? — Mark Allison
I think it is a string. Try echoing DeleteONSuccess.class in your pipeline script — Rik

Rik Rik · Accepted Answer · 2017-01-11T19:03:28

The problem is that the running of a script actually needs a node to run on, so in your case the cause of the error is that you try to run a bat command outside of a node context

node {
...
}
stage('delete') {
    if(DeleteOnSuccess)
    {
        bat 'SET /p VM_NAME=<DeleteVM.txt' // <- this is actually causing the error
        echo "Deleting VM_NAME: %VM_NAME%"
        def job = build job: 'remove-vm', parameters: [[$class:    'StringParameterValue', name: 'VM_NAME', value: '${VM_NAME}']]
    }
}

You can fix this by wrapping this part also inside a node by either putting it inside the first node or add a new one, depending on what you want

Besides that, if the DeleteOnSuccess variable is a build parameter, it will be a string. I am not sure, but I think this is because it is injected as an environment variable, which are also strings (even if it is of type BooleanParameter. I guess that is only a UI thing so it will show up as checkbox). You can check that by echoing DeleteOnSuccess.class. This will tell you its class

 if(DeleteOnSuccess) { ... }

will always run the conditional block. You can fix this by either converting it to a bool using the toBoolean() extension method, or checking it against the the string true: DeleteOnSuccess == "true", like you did. The extension method has the advantage that it will also allow values "1" and "True" as true

How to run downstream job conditionally based on a parameter in Jenkins pipeline?

1 Answers