Jenkins Declarative Pipeline: How to inject properties

Question

I have Jenkins 2.19.4 with Pipeline: Declarative Agent API 1.0.1. How does one use readProperties if you cannot define a variable to assign properties read to?

For e

Answer 1

You can use the script step inside the steps tag to run arbitrary pipeline code.

So something in the lines of:

pipeline {
    agent any
    stages {
        stage('A') {
            steps {
                writeFile file: 'props.txt', text: 'foo=bar'
                script {
                    def props = readProperties file:'props.txt';
                    env['foo'] = props['foo'];
                }
            }
        }
        stage('B') {
            steps {
                echo env.foo
            }
        }
    }
}

Here I'm using env to propagate the values between stages, but it might be possible to do other solutions.