Loops in Jenkinsfiles

Jenkinsfile

// Related to https://issues.jenkins-ci.org/browse/JENKINS-26481

abcs = ['a', 'b', 'c']

node('master') {
    stage('Test 1: loop of echo statements') {
        echo_all(abcs)
    }
    
    stage('Test 2: loop of sh commands') {
        loop_of_sh(abcs)
    }
    
    stage('Test 3: loop with preceding SH') {
        loop_with_preceding_sh(abcs)
    }
    
    stage('Test 4: traditional for loop') {
        traditional_int_for_loop(abcs)
    }
}

@NonCPS // has to be NonCPS or the build breaks on the call to .each
def echo_all(list) {
    list.each { item ->
        echo "Hello ${item}"
    }
}
// outputs all items as expected

@NonCPS
def loop_of_sh(list) {
    list.each { item ->
        sh "echo Hello ${item}"
    }
}
// outputs only the first item

@NonCPS
def loop_with_preceding_sh(list) {
    sh "echo Going to echo a list"
    list.each { item ->
        sh "echo Hello ${item}"
    }
}
// outputs only the "Going to echo a list" bit

//No NonCPS required
def traditional_int_for_loop(list) {
    sh "echo Going to echo a list"
    for (int i = 0; i < list.size(); i++) {
        sh "echo Hello ${list[i]}"
    }
}
// echoes everything as expected

👍

Hi All,

Nice one , But What If I need to read the values from a text file here , instead of putting that in an array , Any Help on this will be highly appreciated.

https://stackoverflow.com/questions/20340688/reading-strings-from-a-file-and-putting-them-into-an-array-with-groovy ?

bear in mind though that some File method signatures are considered risky in Jenkins.

Or if you set up the array in a groovy file you can read it from a text file:

      sh('curl -sSLO https://raw.githubusercontent.com/redhat-developer/codeready-workspaces/crw-2-rhel-8/product/util.groovy')
      def util = load "${WORKSPACE}/util.groovy"

Hi @nickboldt

Thanks for the Inputs on this , But It is not clearly working , let me tell you the Exact requirement which I am trying to achive.

Actually we have a text file where I have list of json Values (For E.g., ECS:repositoryname:Tagname) , So from that File I have already written a shell script to get All repository names in one text file and Tag names in another text file during the build, Till now Its working fine . But now I need to read the Tag values from that text file and need to clone that particular tag based on the repository values and then while cloning need to run the check-marx scan by using a single groovy command , So for that I need to read the values from the textfile and need to checkout the Repositories. For that I am trying different ways to read values from file , But I am unable to do it

Any help on this is Highly appreciated.

Hi @abgm,

I have tried your script and Its working fine , But Instead of passing values in an array as you did , How can I read them from a file and print them .

Hi All,

Actually I wanted to read files from Text file and wanted to Iterate the same in for loop and print values one by one , Any Suggestions on this is highly appreciated as I have spend so much time on this , But still couldnt find out , I an able to read the values but not able to print them using for loop

Sharing the code below for refernce

pipeline {
agent any
stages {
stage('Example') {
steps {

            script {
                def browsers =   readFile(file: 'repos.txt') 
                def lines = browsers.readLines()
                
                for (int i = 0; i < lines.size(); ++i) {
                    
                    echo "${lines}"
                }
            }
        }
    }
}

}

getting different outputs lets say getting all values at a time five times as size of file is five words , But I need one by one only one at a time in for loop

Very preatty :D

Thanks, looking for the same .