Jenkins Pipeline Conditional Environmental Variables - jenkins

Question

I have a set of static environmental variables in the environmental directive section of a declarative pipeline. These values are available to every stage in the pipeline.
I want the values to change based on an arbitrary condition.
Is there a way to do this?
pipeline {
agent any
environment {
if ${params.condition} {
var1 = '123'
var2 = abc
} else {
var1 = '456'
var2 = def
}
}
stages {
stage('One') {
steps {
script {
...
echo env.var1
echo env.var2
...
}
}
}
}
stag('Two'){
steps {
script {
...
echo env.var1
echo env.var2
...
}
}
}

Answer 1

Looking for the same thing I found a nice answer in other question:
Basically is to use the ternary conditional operator
pipeline {
agent any
environment {
var1 = "${params.condition == true ? "123" : "456"}"
var2 = "${params.condition == true ? abc : def}"
}
}
Note: keep in mind that in the way you wrote your question (and I did my answer) the numbers are Strings and the letters are variables.

Answer 2

I would suggest you to create a stage "Environment" and declare your variable according to the condition you want, something like below:-
pipeline {
agent any
environment {
// Declare variables which will remain same throughout the build
}
stages {
stage('Environment') {
agent { node { label 'master' } }
steps {
script {
//Write condition for the variables which need to change
if ${params.condition} {
env.var1 = '123'
env.var2 = abc
} else {
env.var1 = '456'
env.var2 = def
}
sh "printenv"
}
}
}
stage('One') {
steps {
script {
...
echo env.var1
echo env.var2
...
}
}
}
stage('Two'){
steps {
script {
...
echo env.var1
echo env.var2
...
}
}
}
}
}

Answer 3

Suppose we want to use optional params for downstream job if it is called from upsteam job, and default params if downsteam job is called by itself.
But we don't want to have "holder" params with default value in downstream for some reason.
This could be done via groovy function:
upstream Jenkinsfile - param CREDENTIALS_ID is passed downsteam
pipeline {
stage {
steps {
build job: "my_downsteam_job_name",
parameters [string(name: 'CREDENTIALS_ID', value: 'other_credentials_id')]
}
}
}
downstream Jenkinsfile - if param CREDENTIALS_ID not passed from upsteam, function returns default value
def getCredentialsId() {
if(params.CREDENTIALS_ID) {
return params.CREDENTIALS_ID;
} else {
return "default_credentials_id";
}
}
pipeline {
environment{
TEST_PASSWORD = credentials("${getCredentialsId()}")
}
}

Answer 4

you can get another level of flexibility, using maps:
stage("set_env_vars") {
steps {
script {
def MY_MAP1 = [A: "123", B: "456", C: "789"]
def MY_MAP2 = [A: "abc", B: "def", C: "ghi"]
env.var1 = MY_MAP1."${env.switching_var}"
env.var2 = MY_MAP2."${env.switching_var}"
}
}
}
This way, more choices are possible.