Jenkinsfile execute stage only if parameter not initialized

Question

I have a multibranch pipeline job, that executes a declarative pipeline Jenkins file. In this declarative pipeline, I have 2 parameters, a choice param, and a string param. On the first run of a branch due to params not yet loaded from the Jenkins file(it has not run yet, and they have to be in the Jenkins file), the job fails with the error of not knowing my params. My question is: How can I run a stage only if I see that the Jenkins param was not initialized?

Answer 1

I've solved it this way: add a 'default' value to your choice, and check on it in your stage with an expression. Could be done the same with the String param.

parameters {
    choice(choices: ['none', 'internal', 'alpha', 'beta'], description: 'Deploy app to selected track', name: 'DEPLOY_TRACK')
}

And then in your stage:

stage('Deploy') {
    when {
        // Only execute this stage when selected DEPLOY_TRACK is `internal`, `alpha` or `beta`
        expression {
            return params.DEPLOY_TRACK != 'none'
        }
    }
    ...
}