Jenkins Pipeline, use an Env Var within emailext plugin - jenkins-pipeline

Question

My Pipeline is generating a dynamic recipient list based on each Job execution.I'm trying to use that list which I set it as a Variable, to use in the 'To' section of the emailext plugin, the Problem is that the Content of the variable is not resolved once using the mailext part.
pipeline {
agent {
label 'master'
}
options {
timeout(time: 20, unit: 'HOURS')
}
stages {
stage('Find old Projects') {
steps {
sh '''
find $JENKINS_HOME/jobs/* -type f -name "nextBuildNumber" -mtime +1550|egrep -v "configurations|workspace|modules|promotions|BITBUCKET"|awk -F/ '{print $6}'|sort -u >results.txt
'''
}
}
stage('Generate recipient List') {
steps {
sh '''
for Project in `cat results.txt`
do
grep "mail.com" $JENKINS_HOME/jobs/$Project/config.xml|grep -iv "Ansprechpartner" | awk -F'>' '{print $2}'|awk -F'<' '{print $1}'>> recipientList.txt
done
recipientList=`sort -u recipientList.txt`
echo $recipientList
'''
}
}
stage('Generate list to Shelve or Delete') {
steps {
sh '''
for Project in `cat results.txt`
do
if [ -f "$JENKINS_HOME/jobs/$Project/nextBuildNumber" ]; then
nextBuildNumber=`cat $JENKINS_HOME/jobs/$Project/nextBuildNumber`
if [ $nextBuildNumber == '1' ]; then
echo "$JENKINS_HOME/jobs/$Project" >> jobs2Delete.txt
echo "$Project" >> jobList2Delete.txt
else
echo "$JENKINS_URL/job/$Project/shelve/shelveProject" >> Projects2Shelve.txt
echo "$Project" >> ProjectsList2Shelve.txt
fi
fi
done
'''
}
}
stage('Send email') {
steps {
emailext to: 'admin#mail.com',
from: 'jenkins#mail.com',
attachmentsPattern: 'ProjectsList2Shelve.txt,jobList2Delete.txt',
subject: "This is a subject",
body: "Hello\n\nAttached two lists of Jobs, to archive or delete,\nPlease Aprove or Abort the Shelving / Delition of the Projects:\n${env.JOB_URL}\n\nBlue Ocean:\n${env.RUN_DISPLAY_URL}\n\nyour Team"
}
}
stage('Aprove or Abort') {
steps {
input message: 'OK to Shelve and Delete projects? \n Review the jobs list (Projects2Shelve.txt, jobs2Delete.txt) sent to your email', submitter: 'someone'
}
}
stage('Shelve or Delete') {
parallel {
stage('Shelve Project') {
steps {
withCredentials([usernamePassword(credentialsId: 'XYZ', passwordVariable: 'PA', usernameVariable: 'US')]) {
sh '''
for job2Shelve in `cat Projects2Shelve.txt`
do
curl -u $US:$PA $job2Shelve
done
'''
}
}
}
stage('Delete Project') {
steps {
sh '''
for job2Del in `cat jobs2Delete.txt`
do
echo "Removing $job2Del"
done
'''
}
}
}
}
}
post {
success {
emailext to: "$recipientListTest",
from: 'jenkins#mail.com',
attachmentsPattern: 'Projects2Shelve.txt,jobs2Delete.txt',
subject: "This is a sbject",
body: "Hallo\n\nAttached two lists of Jobs which archived or deleted due to inactivity of more the 400 days\n\n\nyour Team"
}
}
}

Answer 1

I figured out that the only way would be to add a script part as part of the post section, together with a variable Definition outside of the Pipeline block:
post {
success {
script {
RECIPIENTLIST = sh(returnStdout: true, script: 'cat recipientListTest.txt')
}
emailext to: "${RECIPIENTLIST}",
from: 'jenkins#mail.com',
attachmentsPattern: 'Projects2Shelve.txt,jobs2Delete.txt',
subject: "MY SUBJECT",
body: "MY BODY"
}

Answer 2

when you execute a sh command, you cannot reuse the variables that you set within that command. You need to do something like this:
on top you your pipeline file to make this variable global
def recipientsList
then execute your shell command and retrieve the output
recipientsList = sh (
script: '''for Project in `cat results.txt`
do
grep "mail.com" $JENKINS_HOME/jobs/$Project/config.xml|grep -iv "Ansprechpartner" | awk -F'>' '{print $2}'|awk -F'<' '{print $1}'>> recipientList.txt
done
recipientList2=`sort -u recipientList.txt`
echo $recipientList2
''',
returnStdout: true
).trim()
Now in your email you can use the variable $recipientList...
I renamed your bash variable to recipientList2 to avoid confusion.
EDIT: I don't know what you want to obtain, but consider using some default recipients provided by emailext:
recipientProviders: [ developers(), culprits(), requestor(), brokenBuildSuspects(), brokenTestsSuspects() ],