Call stage from function in Jenkinsfile - groovy

Question

I have in my Jenkinsfile:
def foo = ["1", "2", "3"]
def parallelStagesFromMap = foo.collectEntries {
["Build ${it}" : generateStage(it)]
}
def generateStage(bar) {
return {
stage("Build ${bar}") {
echo "Building for ${bar}"
}
}
}
I can then use them with parallel parallel parallelStagesFromMap but now I'm trying to call one in particular, for example:
generateStage("a") and it is just skipped... Am I missing anything?

Answer 1

You are missing closure invocation. Your generateStage(name) method returns a closure, and this closure is not invoked implicitly. (It works with parallel stages, because parallel method expects a map where each entry value is a closure, so it iterates over all map entries and invokes collected closures).
Here is what your example should look like to add a non-parallel stage to the pipeline using generateStage(name) method:
def foo = ["1", "2", "3"]
def parallelStagesFromMap = foo.collectEntries {
["Build ${it}" : generateStage(it)]
}
def generateStage(bar) {
return {
stage("Build ${bar}") {
echo "Building for ${bar}"
}
}
}
node {
parallel parallelStagesFromMap
generateStage("skipped") // no invocation, stage is skipped
generateStage("nonparallel").call()
}
And here is what the Blue Ocean UI looks like after running this exemplary pipeline: