Using a docker command as an variable in a Jenkins sh script? - docker

Question

I am working on a CI/DC Pipeline where I have a DEV, TEST and Prod Server. With a Jenkins Pipeline i deploy my newest Image onto my DEV-Server. Now i want to take the image of my DEV-Server by reading out the sha256 id and put it on my TEST-Server.
I have a Jenkins Pipeline for that:
pipeline {
agent any
tools {
dockerTool 'docker-19.03.9'
}
environment {
}
stages {
stage('DeployToTEST-Angular') {
steps {
script {
echo 'Deploying image...'
sh 'docker stop mycontainertest'
sh 'docker rm mycontainertest'
sh 'docker run -d --name mycontainertest [cant show the envirmoments i give with] --restart always angular:latest'
}
}
}
}
As you see i currently use the :latest tag, but i want something like this:
pipeline {
agent any
tools {
dockerTool 'docker-19.03.9'
}
environment {
}
stages {
stage('DeployToTEST-Angular') {
steps {
script {
echo 'Deploying image...'
sh 'docker stop mycontainertest'
sh 'docker rm mycontainertest'
sh 'docker run -d --name mycontainertest [cant show the envirmoments i give with] --restart always \$imageofDev'
}
}
}
}
$imageofDev = docker inspect mycontainerdev | grep -o 'sha256:[^"]*' // this command works and give my back the raw sha256 number
So that it uses the actuall sha256 number of my dev image
I dont know how i can define this variable and later use the value of it in this Jenkins Pipeline. How can i do this?

Answer 1

When you build the image, choose an image name and tag that you can remember later. Jenkins provides several environment variables that you can use to construct this, such as BUILD_NUMBER; in a multibranch pipeline you also have access to BRANCH_NAME and CHANGE_ID; or you can directly run git in your pipeline code.
def shortCommitID = sh script: 'git rev-parse --short HEAD', returnStdout: true
def dockerImage = "project:${shortCommitID.trim()}"
def registry = 'registry.example.com'
def fullDockerImage "${registry}/${dockerImage}"
Now that you know the Docker image name you're going to use everywhere you can just use it; you never need to go off and look up the image ID. Using the scripted pipeline Docker integration, for example:
docker.withRegistry("https://${registry}") {
def image = docker.build(dockerImage)
image.push
}
Since you know the registry/image:tag name, you can just use it in other Jenkins directives too
def containerName = 'container'
// stop an old container, if any
sh "docker stop ${containerName} || true"
sh "docker rm ${containerName} || true"
// start a new container that outlives this pipeline
sh "docker run -d --name ${containerName} ${fullDockerImage}"