groovy - How to list all `env` properties within jenkins pipeline job?

Question

Given a jenkins build pipeline, jenkins injects a variable env into the node{}. Variable env holds environment variables and values.

For example, environment variable BRANCH_NAME can be accessed with

node {
    echo ${env.BRANCH_NAME}
    ...

I want to echo all env properties within the jenkins pipeline

...considering that I do not know all properties ahead of time.

I am looking for code like

node {
    for(e in env){
        echo e + " is " + ${e}
    }
    ...

which would echo something like

 BRANCH_NAME is myBranch2
 CHANGE_ID is 44
 ...

---

I used Jenkins 2.1 for this example.

Answer 1

According to Jenkins documentation for declarative pipeline:

sh 'printenv'

For Jenkins scripted pipeline:

echo sh(script: 'env|sort', returnStdout: true)

The above also sorts your env vars for convenience.