jenkins pipeline passing variables - jenkins

Question

I have a pipeline and I'm building my image through a docker container and it output the image tag, I want to pass that image tag to next stage, when I echo it in the next stage it prints out. but when I use it in a shell it goes empty. here is my pipeline
pipeline {
agent any
stages {
stage('Cloning Git') {
steps {
git( url: 'https://xxx#bitbucket.org/xxx/xxx.git',
credentialsId: 'xxx',
branch: 'master')
}
}
stage('Building Image') {
steps{
script {
env.IMAGE_TAG = sh script: "docker run -e REPO_APP_BRANCH=master -e REPO_APP_NAME=exampleservice -e DOCKER_HUB_REPO_NAME=exampleservice --volume /var/run/docker.sock:/var/run/docker.sock registry.xxxx/build", returnStdout: true
}
}
}
stage('Integration'){
steps{
script{
echo "passed: ${env.IMAGE_TAG}"
sh """
helm upgrade exampleservice charts/exampleservice --set image.tag=${env.IMAGE_TAG}
"""
sh "sleep 5"
}
}
}
}
}
pipeline output
[Pipeline] }
[Pipeline] // script
[Pipeline] }
[Pipeline] // stage
[Pipeline] stage
[Pipeline] { (Integration)
[Pipeline] script
[Pipeline] {
[Pipeline] echo
passed:
b79c3bf-b6eec4f
[Pipeline] sh
[test101] Running shell script
+ helm upgrade exampleservice charts/exampleservice --set image.tag=
getting empty image tag

Answer 1

You should override this by using the 'env'.
Replace your code with this one:
pipeline {
agent any
stages {
stage('Cloning Git') {
steps {
git( url: 'https://xxx#bitbucket.org/xxx/xxx.git',
credentialsId: 'xxx',
branch: 'master')
}
}
stage('Building Image') {
steps{
script {
env.IMAGE_TAG = sh script: "docker run -e REPO_APP_BRANCH=master -e REPO_APP_NAME=exampleservice -e DOCKER_HUB_REPO_NAME=exampleservice --volume /var/run/docker.sock:/var/run/docker.sock registry.xxxx/build", returnStdout: true
}
}
}
stage('Integration'){
steps{
script{
echo "passed: ${env.IMAGE_TAG}"
sh """
helm upgrade exampleservice charts/exampleservice\
--set image.tag="${env.IMAGE_TAG}"
"""
sh "sleep 5"
}
}
}
}
}