Jenkins – How to Use For Loop in Declarative Pipeline

Jenkins

I am having a list of variable like below

allModules = ['module1', 'module2', 'module3', 'module4', 'module11']

I want to use loop then print all the module one by one.

Please let me know the syntax and how to perform this in Jenkins Declarative pipeline

Best Answer

Pure declarative pipelines don't support loops. Use a script step. There's actually an example on that page that does exactly what you want.

A more readable and concise (IMO) solution would use iterators, like so:

steps {
   script {
      allModules.each() {
         echo it
      }
   }
}

Related Solutions

Jenkins Pipeline – Passing Jenkinsfile Variables into Commands

Since it's not guaranteed that your individual stages will run on the same executor node (unless you have the stages wrapped up in the same node block), using files to share information between stages will be unreliable. Instead use variables:

def jobBaseName

stage ('Construct Img name') {
  jobBaseName = sh(
    script: "echo ${BUILD_TAG} | awk '{print tolower($0)}' | sed 's/jenkins-//'",
    returnStdout: true,
  )
}

stage ('Build Target Container') {
  sh "ssh -i ~/ssh_keys/key.key user@somehost 'cd /dockerdata/build/${BUILD_TAG} && docker build -t localrepo/${jobBaseName}:${BUILD_NUMBER} .'"
}

By the way, I would also suggest using sshAgent and Jenkins' built-in credentials store to manage SSH keys instead of manually passing in the -i flag to SSH.

Jenkins Pipeline – Using Parameterized Trigger Plugin

You don't need a plugin at all to do this. The built-in Pipeline build step supports parameters. E.g.:

build(
  job: 'my-job-name',
  parameters: [
    [
      $class: 'StringParameterValue',
      name: 'myStringParameter',
      value: "my value",
    ],
    [
      $class: 'BooleanParameterValue',
      name: 'myBooleanParameter',
      value: true,
    ],
    // etc.
  ],
)

You should also be able to use the syntax generator with the default build step to help generate this code.

Best Answer

Related Solutions

Jenkins Pipeline – Passing Jenkinsfile Variables into Commands

Jenkins Pipeline – Using Parameterized Trigger Plugin

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