_dynamicParallelStepForJenkinsPipeline.md

A custom step for Jenkins pipelines that allows scaling a task n times in parallel, specifying parameters for each thread

customStep.groovy

// vars/customStep.groovy - see https://jenkins.io/doc/book/pipeline/shared-libraries/#defining-custom-steps

/*
  This step allows executing a custom step with trace header and footer.
*/
def call(String name, Closure step) {
    echo "[Pipeline] $name" + "\n" + '[Pipeline] {'

    try {
        step()
    } finally {
        echo "[Pipeline] // $name\n" + '[Pipeline] }'
    }
}

dynamicParallel.groovy

// vars/dynamicParallel.groovy - see https://jenkins.io/doc/book/pipeline/shared-libraries/#defining-custom-steps

/*
  This step allows calling a stage multiple times in parallel with different
  parameters for each invocation.

  Example:

      dynamicParallel(name: "Echo Stuff", paramsForStages: [
          [number: 5, direction: 'north'],
          [number: 6, direction: 'south'],
          [number: 2, direction: 'west']
      ]) { stageParams ->
          echo "number: ${stageParams.number} | direction: ${stageParams.direction}"
      }
*/
def call(Map params, Closure stage) {
    customStep('dynamicParallel') {
        def stages = [:]

        for (def _stageId = 0; _stageId < params.paramsForStages.size(); _stageId++) {
            def stageId = _stageId + 1
            def stageName = "${params.name}-$stageId"
            def stageParams = params.paramsForStages[_stageId]

            stages[stageName] = {
                script {
                    stage(stageParams, stageId, stageName)
                }
            }
        }

        parallel stages
    }
}