How can I use `def` in jenkins pipeline
You can use def with a declarative pipeline, just not inside it eg
def agentLabel
if (BRANCH_NAME =~ /^(staging|master)$/) {
agentLabel = "prod"
} else {
agentLabel = "master"
}
pipeline {
agent { node { label agentLabel } }
..
As @Rob said, There are 2 types of pipelines: scripted
and declarative
. It is like imperative
vs declarative
. def
is only allowed in scripted
pipeline or wrapped in script {}
.
Scripted pipeline (Imperative)
Start with node
, and def
or if
is allowed, like below. It is traditional way.
node {
stage('Example') {
if (env.BRANCH_NAME == 'master') {
echo 'I only execute on the master branch'
} else {
echo 'I execute elsewhere'
}
}
}
Declarative pipeline (Preferred)
Start with pipeline
, and def
or if
is NOT allowed, unless it is wrapped in script {...}
. Declarative pipeline make a lot things easy to write and read.
time trigger
pipeline {
agent any
triggers {
cron('H 4/* 0 0 1-5')
}
stages {
stage('Example') {
steps {
echo 'Hello World'
}
}
}
}
when
pipeline {
agent any
stages {
stage('Example Build') {
steps {
echo 'Hello World'
}
}
stage('Example Deploy') {
when {
branch 'production'
}
steps {
echo 'Deploying'
}
}
}
}
Parallel
pipeline {
agent any
stages {
stage('Non-Parallel Stage') {
steps {
echo 'This stage will be executed first.'
}
}
stage('Parallel Stage') {
when {
branch 'master'
}
failFast true
parallel {
stage('Branch A') {
agent {
label "for-branch-a"
}
steps {
echo "On Branch A"
}
}
stage('Branch B') {
agent {
label "for-branch-b"
}
steps {
echo "On Branch B"
}
}
}
}
}
}
embedded with scripted code
pipeline {
agent any
stages {
stage('Example') {
steps {
echo 'Hello World'
script {
def browsers = ['chrome', 'firefox']
for (int i = 0; i < browsers.size(); ++i) {
echo "Testing the ${browsers[i]} browser"
}
}
}
}
}
}
To read more declarative pipeline grammar, please refer the official doc here