tagging docker images with Jenkins pipeline parameter

Question

I am trying to tag my docker image`. I am using Jenkins to do that for me by declaring a string parameter.

In the docker-compose.yml file I have my image like so:

image: api:"${version}"

I get an error saying the tag is incorrect.

In my Jenkins pipeline I have a string parameter named version with default LATEST. However, I want to be able to enter v1 or v2 which will be used as an image tag.

I am doing it using blue-green deployment.

Answer 1

You can set the VERSION in the environment for the build using withEnv in your pipeline, for example:

# Jenkinsfile
---
stage('build'){
    node('vagrant'){
        withEnv([
           'VERSION=0.1'
        ]){
            git_checkout()
            dir('app'){
                ansiColor('xterm') {
                    sh 'mvn clean install'
                }
            }
            // build docker image with version
            sh 'docker build --rm -t app:${VERSION} .'
        }
    }
}

def git_checkout(){
    checkout([
        $class: 'GitSCM',
        branches: [[name: '*/' + env.BRANCH_NAME]],
        doGenerateSubmoduleConfigurations: false,
        extensions: [
            [$class: 'SubmoduleOption', disableSubmodules: false, parentCredentials: true, recursiveSubmodules: false, reference: '', trackingSubmodules: true],
            [$class: 'AuthorInChangelog'],
            [$class: 'CloneOption', depth: 0, noTags: false, reference: '', shallow: false]
        ],
        submoduleCfg: [],
        userRemoteConfigs: [
            [credentialsId: '...', url: 'ssh://vagrant@ubuntu18/usr/local/repos/app.git']
        ]
    ])
}

# Dockerfile
---
FROM ubuntu:18.04

RUN apt update && \
    apt install -y openjdk-11-jre && \
    apt clean

COPY app/special-security/target/special-security.jar /bin

ENTRYPOINT ["java", "-jar", "/bin/special-security.jar"]

The version number set in the Jenkins build environment is used by the docker build command.

Note: the java application that I'm building with maven (e.g. mvn clean install) is purely for example purposes, the code is available https://stackoverflow.com/a/54450290/1423507. Also, the colorized output in Jenkins console requires the AnsiColor Plugin as explained https://stackoverflow.com/a/53227633/1423507. Finally, not using docker-compose in this example, there is no difference for setting the version in the environment.

Answer 2

The problem

In my Jenkins pipeline I have a string parameter named version with default LASTEST. However I want to be able to enter v1 or v2 and that is the tag the container uses.

Assuming that docker compose runs inside of you Jenkins pipeline then the ${version} you use indocker-compose.yml` must be available in the shell environment of the Jenkins pipeline, otherwise will evaluate to nothing, thus giving you the error saying the tag is invalid.

The solution

Sorry but I am not familiar with Jenkins so I can't tell how you can set properly the value for ${version} in the shell environment is running, thus you need to do some search around this.

Tip

Just as a tip in docker-compose.yml you can use bash expansion to assign default values to the variables you use, like:

image: api:"${version:-latest}"

or if you want a explicit error

image: api:"${version? Mipssing version for docker image!!!}"