Use Jenkins 'Mailer' inside pipeline workflow

Question

I'd like to leverage the existing Mailer plugin from Jenkins within a Jenkinsfile that defines a pipeline build job. Given the following simple failure script I would expect an email on every build.

#!groovy

stage 'Test'
node {
    try {
        sh 'exit 1'
    } finally {
        step([$class: 'Mailer', notifyEveryUnstableBuild: true, recipients: '[email protected]', sendToIndividuals: true])
    }
}

The output from the build is:

Started by user xxxxx
[Pipeline] stage (Test)
Entering stage Test
Proceeding
[Pipeline] node
Running on master in /var/lib/jenkins/jobs/rpk-test/workspace
[Pipeline] {
[Pipeline] sh
[workspace] Running shell script
+ exit 1
[Pipeline] step
[Pipeline] }
[Pipeline] // node
[Pipeline] End of Pipeline
ERROR: script returned exit code 1
Finished: FAILURE

As you can see, it does record that it performs the pipeline step immediately after the failure, but no emails get generated.

Emails in other free-style jobs that leverage the mailer work fine, its just invoking via pipeline jobs.

This is running with Jenkins 2.2 and mailer 1.17.

Is there a different mechanism by which I should be invoking failed build emails? I don't need all the overhead of the mail step, just need notifications on failures and recoveries.

Answer 1

In Pipeline failed sh doesn't immediately set the currentBuild.result to FAILURE whereas its initial value is null. Hence build steps that rely on the build status like Mailer might work seemingly incorrect.

You can check it by adding a debug print:

stage 'Test'
node {
    try {
        sh 'exit 1'
    } finally {
        println currentBuild.result  // this prints null
        step([$class: 'Mailer', notifyEveryUnstableBuild: true, recipients: '[email protected]', sendToIndividuals: true])
    }
}

This whole pipeline is wrapped with exception handler provided by Jenkins that's why Jenkins marks the build as failed in the the end.

So if you want to utilize Mailer you need to maintain the build status properly. For instance:

stage 'Test'
node {
    try {
        sh 'exit 1'
        currentBuild.result = 'SUCCESS'
    } catch (any) {
        currentBuild.result = 'FAILURE'
        throw any //rethrow exception to prevent the build from proceeding
    } finally {
        step([$class: 'Mailer', notifyEveryUnstableBuild: true, recipients: '[email protected]', sendToIndividuals: true])
    }
}

If you needn't to rethrow the exception you can use catchError. It is a Pipeline built-in which catches any exception within its scope, prints it into console and sets the build status. Example:

stage 'Test'
node {
    catchError {
        sh 'exit 1'
    } 
    step([$class: 'Mailer', notifyEveryUnstableBuild: true, recipients: '[email protected]', sendToIndividuals: true])
}