Jenkins pipeline with parallel

Question

Here is my Jenkins pipeline that i am trying to execute. I am following this tutorial:

pipeline {
    agent any
    stages {
        stage('one') {
            parallel "first" : {               
                    echo "hello"                
            },
            "second": {                
                    echo "world"            
            }
        }
        stage('two') {
            parallel "first" : {               
                    echo "hello"                
            },
            "second": {                
                    echo "world"            
            }
        }
    }
}

But the job fails with following message.

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
WorkflowScript: 4: Unknown stage section "parallel". Starting with version 0.5, steps in a stage must be in a steps block. @ line 4, column 9.
           stage('one') {
           ^

WorkflowScript: 12: Unknown stage section "parallel". Starting with version 0.5, steps in a stage must be in a steps block. @ line 12, column 9.
           stage('two') {
           ^

WorkflowScript: 4: Nothing to execute within stage "one" @ line 4, column 9.
           stage('one') {
           ^

WorkflowScript: 12: Nothing to execute within stage "two" @ line 12, column 9.
           stage('two') {
           ^

4 errors

Can someone please help me out why this is failing.

Answer 1

You need to add a steps block after your stage declaration.

    pipeline {
    agent any
    stages {
        stage('Example Stage 1') {
            steps {
                parallel(
                        "step 1": { echo "hello" },
                        "step 2": { echo "world" },
                        "step 3": { echo "world" }
                )
            }
        }
        stage('Example Stage 2') {
            steps {
                parallel(
                        "step 1": { echo "hello" },
                        "step 2": { echo "world" },
                        "step 3": { echo "world" }
                )
            }
        }
    }
}

To Make your Stages Parallel use this, both solutions show up very similar in Blue Ocean :

    pipeline {
    agent any
    stages {
        stage('Example Stage') {
            parallel {
                stage('Stage 1') {
                    steps { sh 'echo stage 1 passed' }
                }
                stage('Stage 2') {
                    steps { sh 'echo stage 2 passed' }
                }
                stage('Stage 3') {
                    steps { sh 'echo stage 3 passed' }
                }
            }
        }
    }
}

Answer 2

You need to upgrade the Declarative Pipeline plugin on your Jenkins to Version 1.2 (Sept 21, 2017) or above

Answer 3

In declarative pipeline, in case if you want to add stage, inside steps, this nesting is also possible.

If the steps are same in that case you can declare step as a function.

def steps  = ['first', 'second'] 
def generateSteps(stepLabel) {
    return {
        step("${stepLabel}") {
                echo "Running on ${stepLabel}"
        }
    }
}
def parallelStepMap = steps.collectEntries {
    ["${it}" : generateSteps(it)]
}
pipeline {
    agent any
    stages {
        stage('non-parallel stage') {
            steps {
                echo 'This stage will be executed first.'
            }
        }
 
        stage('parallel stage') {
            steps {
                script {
                    parallel parallelStepMap
                }
            }
        }       
    }
}

General need is to execute different stages into different nodes. in such case above function can be modified to execute on different agent nodes as follows.

def agents  = ['master', 'agent1', 'agent2']
 
 
def generateStage(nodeLabel) {
    return {
        stage("Runs on ${nodeLabel}") {
            node(nodeLabel) {
                echo "Running on ${nodeLabel}"
            }
        }
    }
}
def parallelStagesMap = agents.collectEntries {
    ["${it}" : generateStage(it)]
}
pipeline {
    agent none
    stages {
        stage('non-parallel stage') {
            steps {
                echo 'This stage will be executed first.'
            }
        }
 
        stage('parallel stage') {
            steps {
                script {
                    parallel parallelStagesMap
                }
            }
        }       
    }
}

With nodelabel defined inside the function and agent none during start of pipeline, the stages will be executed into different nodes.