How to use multiple docker repositories in a Jenkins pipeline

Introduction

Using multiple Docker repositories within a Jenkins pipeline can enhance your CI/CD process by allowing for greater flexibility and separation of concerns. This tutorial will guide you through the steps necessary to use multiple Docker repositories in a Jenkins pipeline effectively.

Prerequisites

To follow along with this tutorial, you will need:

• A Jenkins server up and running
• Access to at least two Docker repositories
• A basic understanding of Docker and Jenkins pipeline syntax

Configuring Jenkins

Before you begin, ensure that Jenkins is configured with the necessary plugins to work with Docker. The Docker Pipeline plugin should be installed and properly set up.

Setting Up Multiple Docker Repositories

Working with multiple Docker repositories requires storing and managing different credentials and properly structuring your pipeline script to interact with each repository.

Storing Docker Credentials

Use the Jenkins credentials store to securely save the login information for each Docker repository. This can typically be done under the “Credentials” section of Jenkins.

Pipeline Syntax for Multiple Repositories

You will need to use environment variables or scripts to log into the Docker repositories during the pipeline execution. The withCredentials or docker.withRegistry syntax can be used.

Example Pipeline Using Multiple Docker Repositories

The following is an example of a Jenkins pipeline script that logs in to two different Docker repositories and pulls images from them.

pipeline {
    agent any
    environment {
        REPO_ONE = 'docker.repo.one'
        REPO_TWO = 'docker.repo.two'
    }
    stages {
        stage('Login to Docker Repository One') {
            steps {
                script {
                    docker.withRegistry("https://$REPO_ONE", "repo-one-credentials-id") {
                        // Pull a Docker image from Repository One
                        docker.image('some-image:latest').pull()
                    }
                }
            }
        }
        stage('Login to Docker Repository Two') {
            steps {
                script {
                    docker.withRegistry("https://$REPO_TWO", "repo-two-credentials-id") {
                        // Pull a Docker image from Repository Two
                        docker.image('another-image:latest').pull()
                    }
                }
            }
        }
        // Additional stages can be added here
    }
}

Troubleshooting

Issues can arise when trying to use multiple docker repositories. Common problems include credential management and repository accessibility. Ensure the right credentials are being used for their corresponding repositories and that network policies allow Jenkins to communicate with the Docker repositories.

Summary

In conclusion, integrating multiple Docker repositories into a Jenkins pipeline requires careful setup of credentials, concise pipeline syntax, and proper management of login/logout procedures in your script. The example provided illustrates a typical scenario for pulling Docker images from different repositories.

References

• Docker Pipeline plugin documentation
• Jenkins official documentation
• Docker official documentation