How to use post steps with Jenkins pipeline on multiple agents? - jenkins

Question

When using the Jenkins pipeline where each stage runs on a different agent, it is good practice to use agent none at the beginning:
pipeline {
agent none
stages {
stage('Checkout') {
agent { label 'master' }
steps { script { currentBuild.result = 'SUCCESS' } }
}
stage('Build') {
agent { label 'someagent' }
steps { bat "exit 1" }
}
}
post {
always {
step([$class: 'Mailer', notifyEveryUnstableBuild: true, recipients: "test#test.com", sendToIndividuals: true])
}
}
}
But doing this leads to Required context class hudson.FilePath is missing error message when the email should go out:
[Pipeline] { (Declarative: Post Actions)
[Pipeline] step
Required context class hudson.FilePath is missing
Perhaps you forgot to surround the code with a step that provides this, such as: node
[Pipeline] error
[Pipeline] }
When I change from agent none to agent any, it works fine.
How can I get the post step to work without using agent any?

Answer 1

wrap the step that does the mailing in a node step:
post {
always {
node('awesome_node_label') {
step([$class: 'Mailer', notifyEveryUnstableBuild: true, recipients: "test#test.com", sendToIndividuals: true])
}
}
}

Answer 2

I know this is old but I stumbled on this looking for something related. If you want to run the post step on any node, you can use
post {
always {
node(null) {
step([$class: 'Mailer', notifyEveryUnstableBuild: true, recipients: "test#test.com", sendToIndividuals: true])
}
}
}
https://jenkins.io/doc/pipeline/steps/workflow-durable-task-step/#node-allocate-node Says that the label may be left blank. Many times in a declarative pipeline if something is left blank this results in an error. To work around this, setting it to null will often work.