How to run post actions if setting up the shared library fails? - jenkins

Question

I'm using a shared library via #Library('shared-lib') _. The pipeline script implements post actions. E.g.
post {
always {
script {
// Do stuff
}
}
}
When there's an error with the shared lib then Jenkins just fails the entire build and the post action block isn't executed, as it seems (tested with wrong repository URL and non-existing branch). In case GitHub is down, I want Jenkins to run post actions to notify the issuer of the build that it failed. Is there a way to do this, without having the issuer making API calls of some kind for verification?
Thanks for any suggestion!

Answer 1

One way you can control the loading of the shared library is by Loading libraries dynamically, when you do so you can wrap the loading phase with a try catch block and handle the failure.
However, when using this technique the error will be handled outside the pipeline execution so in order to avoid duplicating the error handler function (that sends notifications) you can define the error handling in a separate methods (or in a shared library) and call it for the catch block and from the post block.
Something like:
try {
library "shared-lib"
}
catch(Exception ex){
// handle the exception
handleError(ex.getMessage())
}
pipeline {
agent any
stages {
stage('Hello') {
steps {
...
}
}
}
post {
always {
script {
handleError(message)
}
}
}
}
def handleError(message){
emailext ...
}
You can also try to load the library inside a pipeline step, thus utilizing the post directive on failure, but this can cause issues with the context of the loaded library and therefore it is not recommended.
You can also of course handle separately each failure type and avoid the need of an external function.
Last thing, shared library failures are usually not handled because if the job failed to load the library for the SCM then it will probably fail to load the pipeline itself form the SCM, so assuming you host them both on the same SCM platform, this scenario is relatively rare.