I have a declarative pipeline jenkinsfile, in which I have 4 stages.
I would like to make so that whenever a specific stage executes(this stage is conditional therefor it will not always execute), all stages after this one are skipped.
For example purposes let's say that this stage is the first stage.
Does anyone knows a way to do it in a declarative pipeline?
Thanks in advance,
Alon
Define a boolean variable e.g. skip = false in the pipeline. When you enter your conditional stage set the variable to true. Make other stages (2-4) dependent on skip variable.
stage("1 - Your conditional stage") {
when {
...
}
steps {
script {
skip = true
}
}
stage("2") {
when {
expression {
return skip == false
}
}
}
...
stage("4") {
when {
expression {
return skip == false
}
}
}
Related
From my experience with Jenkins declarative-syntax pipelines, I'm aware that you can conditionally skip a stage with a when clause. E.g.:
run_one = true
run_two = false
run_three = true
pipeline {
agent any
stages {
stage('one') {
when {
expression { run_one }
}
steps {
echo 'one'
}
}
stage('two') {
when {
expression { run_two }
}
steps {
echo 'two'
}
}
stage('three') {
when {
expression { run_three }
}
steps {
echo 'three'
}
}
}
}
...in the above code block, there are three stages, one, two, and three, each of whose execution is conditional on a boolean variable.
I.e. the paradigm is that there is a fixed superset of known stages, of which individual stages may be conditionally skipped.
Does Jenkins pipeline script support a model where there is no fixed superset of known stages, and stages can be "looked up" for conditional execution?
To phrase it as pseudocode, is something along the lines of the following possible:
my_list = list populated _somehow_, maybe reading a file, maybe Jenkins build params, etc.
pipeline {
agent any
stages {
if (stage(my_list[0]) exists) {
run(stage(my_list[0]))
}
if (stage(my_list[1]) exists) {
run(stage(my_list[1]))
}
if (stage(my_list[2]) exists) {
run(stage(my_list[2]))
}
}
}
?
I think another way to think about what I'm asking is: is there a way to dynamically build a pipeline from some dynamic assembly of stages?
For dynamic stages you could write either a fully scripted pipeline or use a declarative pipeline with a scripted section (e. g. by using the script {…} step or calling your own function). For an overview see Declarative versus Scripted Pipeline syntax and Pipeline syntax overview.
Declarative pipeline is better supported by Blue Ocean so I personally would use that as a starting point. Disadvantage might be that you need to have a fixed root stage, but I usually name that "start" or "init" so it doesn't look too awkward.
In scripted sections you can call stage as a function, so it can be used completely dynamic.
pipeline {
agent any
stages {
stage('start') {
steps {
createDynamicStages()
}
}
}
}
void createDynamicStages() {
// Stage list could be read from a file or whatever
def stageList = ['foo', 'bar']
for( stageName in stageList ) {
stage( stageName ) {
echo "Hello from stage $stageName"
}
}
}
This shows in Blue Ocean like this:
I have a Jenkinsfile which will be triggered by GitLab (using Webhooks).
I want to skip the whole Jenkinsfile's execution if a particular condition is not met.
One way to do this is to apply the same condition on each stage
pipeline {
agent any
stages {
stage ('Stage 1') {
when {
expression {
//Expression
}
}
//do something
}
stage ('Stage 2') {
when {
expression {
//Expression
}
}
//do something
}
stage ('Stage 3') {
when {
expression {
//Expression
}
}
//do something
}
.
.
.
.
}
}
But this seems weird as I want the same condition to be applied for all the stages.
Can we apply similar condition over stages itself ? Like this?
pipeline {
agent any
stages {
when {
expression {
//Expression
}
}
stage ('Stage 1') {
//do something
}
stage ('Stage 2') {
//do something
}
stage ('Stage 3') {
//do something
}
.
.
.
.
}
}
"Can we apply 'when' condition in 'stages' of a Jenkinsfile?" No.
Per Pipeline Syntax, when is only allowed within a stage.
The when directive allows the Pipeline to determine whether the stage should be executed depending on the given condition. The when directive must contain at least one condition. If the when directive contains more than one condition, all the child conditions must return true for the stage to execute. This is the same as if the child conditions were nested in an allOf condition (see the examples below). If an anyOf condition is used, note that the condition skips remaining tests as soon as the first "true" condition is found.
More complex conditional structures can be built using the nesting conditions: not, allOf, or anyOf. Nesting conditions may be nested to any arbitrary depth.
Can you simply have a first stage with the expression and fail/abort the pipeline if met?
I'm trying to skip a stage based a groovy variable and that variable value will be calculated in another stage.
In the below example, Validate stage is conditionally skipped based Environment variable VALIDATION_REQUIRED which I will pass while building/triggering the Job. --- This is working as expected.
Whereas the Build stage always runs even though isValidationSuccess variable is set as false.
I tried changing the when condition expression like { return "${isValidationSuccess}" == true ; } or { return "${isValidationSuccess}" == 'true' ; } but none worked.
When printing the variable it shows as 'false'
def isValidationSuccess = true
pipeline {
agent any
stages(checkout) {
// GIT checkout here
}
stage("Validate") {
when {
environment name: 'VALIDATION_REQUIRED', value: 'true'
}
steps {
if(some_condition){
isValidationSuccess = false;
}
}
}
stage("Build") {
when {
expression { return "${isValidationSuccess}"; }
}
steps {
sh "echo isValidationSuccess:${isValidationSuccess}"
}
}
}
At what phase does the when condition will be evaluated.
Is it possible to skip the stage based on the variable using when?
Based on a few SO answers, I can think of adding conditional block as below, But when options look clean approach. Also, the stage view shows nicely when that particular stage is skipped.
script {
if(isValidationSuccess){
// Do the build
}else {
try {
currentBuild.result = 'ABORTED'
} catch(Exception err) {
currentBuild.result = 'FAILURE'
}
error('Build not happened')
}
}
References:
https://jenkins.io/blog/2017/01/19/converting-conditional-to-pipeline/
stage("Build") {
when {
expression { isValidationSuccess == true }
}
steps {
// do stuff
}
}
when validates boolean values so this should be evaluate to true or false.
Source
Previously asked a question about how to overwrite variables defined in an environment directive and it seems that's not possible.
I want to set a variable in one stage and have it accessible to other stages.
In a declarative pipeline it seems the only way to do this is in a script{} block.
For example I need to set some vars after checkout. So at the end of the checkout stage I have a script{} block that sets those vars and they are accessible in other stages.
This works, but it feels wrong. And for the sake of readability I'd much prefer to declare these variables at the top of the pipeline and have them overwritten. So that would mean having a "set variables" stage at the beginning with a script{} block that just defines vars- thats ugly.
I'm pretty sure I'm missing an obvious feature here. Do declarative pipelines have a global variable feature or must I use script{}
This is working without an error,
def my_var
pipeline {
agent any
environment {
REVISION = ""
}
stages {
stage('Example') {
steps {
script{
my_var = 'value1'
}
}
}
stage('Example2') {
steps {
script{
echo "$my_var"
}
}
}
}
}
Like #mkobit says, you can define the variable to global level out of pipeline block. Have you tried that?
def my_var
pipeline {
agent any
stages {
stage('Example') {
steps {
my_var = 'value1'
}
}
stage('Example2') {
steps {
printl(my_var)
}
}
}
}
For strings, add it to the 'environment' block:
pipeline {
environment {
myGlobalValue = 'foo'
}
}
But for non-string variables, the easiest solution I've found for declarative pipelines is to wrap the values in a method.
Example:
pipeline {
// Now I can reference myGlobalValue() in my pipeline.
...
}
def myGlobalValue() {
return ['A', 'list', 'of', 'values']
// I can also reference myGlobalValue() in other methods below
def myGlobalSet() {
return myGlobalValue().toSet()
}
#Sameera's answer is good for most use cases. I had a problem with appending operator += though. So this did NOT work (MissingPropertyException):
def globalvar = ""
pipeline {
stages {
stage("whatever) {
steps {
script {
globalvar += "x"
}
}
}
}
}
But this did work:
globalvar = ""
pipeline {
stages {
stage("whatever) {
steps {
script {
globalvar += "x"
}
}
}
}
}
The correct syntax is:
For global static variable
somewhere at the top of the file, before pipeline {, declare:
def MY_VAR = 'something'
For global variable that you can edit and reuse accross stages:
At the top of your file, add an import to Field:
import groovy.transform.Field
somewhere before pipeline {, declare:
#Field def myVar
then inside your step, inside a script, set the variable
stage('some stage') {
steps {
script {
myVar = 'I mutate myVar with success'
}
}
}
to go even further, you can declare functions:
before the pipeline {
def initSteps() {
cleanWs()
checkout scm
}
and then
stages {
stage('Init') {
steps {
initSteps()
}
}
}
This worked for me
pipeline {
agent any
stages {
stage('Example') {
steps {
script{
env.my_var = 'value1'
}
}
}
stage('Example2') {
steps {
printl(my_var)
}
}
}
}
I often write Declarative Pipeline jobs where I setup parameters such as "choice". The first time I run the job, it blindly executes using the first value in the list. I don't want that to happen. I want to detect this case and not continue the job if a user didn't select a real value.
I thought about using "SELECT_VALUE" as the first item in the list and then fail the job if that is the value. I know I can use a 'when' condition on each stage, but I'd rather not have to copy that expression to each stage in the pipeline. I'd like to fail the whole job with one check up front.
I don't like the UI for 'input' tasks because the controls are hidden until you hover over a running stage.
What is the best way to validate arguments with a Declarative Pipeline? Is there a better way to detect when the job is run for the first time and stop?
I've been trying to figure this out myself and it looks like the pipeline runs with a fully populated parameters list.
So, the answer to your choice option is to make the first item a value like "please select option" and have your code use when to check that
For example
def paramset = true
pipeline {
parameters {
choice(choices: ['select','test','proof', 'prod'], name: 'ENVI')
}
stages {
stage ('check') {
when { expression { return params.choice.ENVI == 'select' }
steps {
script {
echo "Missing parameters"
paramset = false
}
}
}
stage ('step 1') {
when { expression { return paramset }
steps {
script {
echo "Doing step 1"
}
}
}
stage ('step 2') {
when { expression { return paramset }
steps {
script {
echo "Doing step 2"
}
}
}
stage ('step 3') {
when { expression { return paramset }
steps {
script {
echo "Doing step 3"
}
}
}
}
}