Jenkins Backup and Restore Steps

Taking a backup of a Jenkins server is crucial for several reasons:

• Data Protection: Safeguards against data loss due to hardware failures, software errors, or other incidents.
• Disaster Recovery: Enables quick restoration and resumption of operations if the server is lost or damaged.
• Upgrade or Migration: Facilitates easier upgrades or migrations to different environments with reduced downtime.
• Historical Reference: Provides a historical record of changes for troubleshooting and auditing purposes.

Therefore, regularly taking a backup of the Jenkins server is essential for maintaining system stability and reliability.

Prerequisites

• AWS CLI v2
• An S3 bucket created on AWS
• An IAM role (e.g., s3 full access) for the EC2 instance to push backup data to the S3 bucket

Backup Stage

1. Launch Jenkins1 Server and Create an Admin User

   • In Jenkins1 server, run some jobs (job1, job2, job3).
   • Stop the Jenkins service to perform the backup:

     sudo systemctl stop jenkins

2. Backup Jenkins Home Directory

   • Jenkins writes all files to the /var/lib/jenkins folder. This folder needs to be backed up:

     tar -zvcf jenkins-backup-<date>.tar.gz /var/lib/jenkins
     tar -zvcf jenkins-backup-$(date +%Y-%m-%d).tar.gz --exclude='/var/lib/jenkins/workspace' /var/lib/jenkins

3. Copy Backup to S3 Bucket

   • Copy the backup file to the S3 bucket:

     aws s3 cp jenkins-backup-<date>.tar.gz s3://<s3-bucket-name>/jenkins-backup-<date>.tar.gz

   • Verify the backup file in the S3 bucket.

Restore Stage

1. Destroy Jenkins1 Server

   • For testing purposes, destroy the Jenkins1 server.

2. Create Jenkins2 Server

   • Launch a new Jenkins2 server (install Jenkins from user data while launching).
   • Install the Jenkins package.
   • Start Jenkins service and access it via the browser, but do not log in with the initial admin password.
   • We need to login into Jenkins2 using Jenkins1 server admin user details from the s3 backup copy.
   • We will already have /var/lib/Jenkins folder in Jenkins2 server

3. Stop Jenkins Service on Jenkins2

   • Stop the Jenkins service to perform the restore activity:

     sudo systemctl stop jenkins

4. Restore Backup Copy to Jenkins2 Server

   • Attach the IAM role (s3 full access) to Jenkins2 server.
   • Pull the backup copy from the S3 bucket into Jenkins2 server:

     aws s3 cp s3://<s3-bucket-name>/jenkins-backup-<date>.tar.gz jenkins-backup.tar.gz

   • Remove the existing Jenkins home directory:

     sudo rm -rf /var/lib/jenkins

   • Extract the backup file to the Jenkins home directory:

     tar -zxvf jenkins-backup.tar.gz -C /

     • The above command will restore that particular backup file into that particular location

5. Start Jenkins Service

   • Start the Jenkins service and check its status:

     sudo systemctl start jenkins
     sudo systemctl status jenkins

6. Access Jenkins2 via Browser

   • Go to Jenkins2 browser and refresh the page. It will prompt for the admin username and password.
   • Provide the admin username and password from Jenkins1. You will be logged in as these details are present in the backup copy.
   • Verify that all job configurations (job1, job2, job3) from Jenkins1 server are present in Jenkins2 server.

Automation

• Set Up Cron Job for Regular Backups
  • Configure a cron job to automate Jenkins backup as per the organization's requirement. This ensures regular backups without manual intervention.

Suggestions and Additional Notes:

1. Security: Ensure that the backup files and S3 bucket are secured with appropriate permissions to prevent unauthorized access.
2. Testing: Regularly test the backup and restore process to ensure that it works correctly and that no data is lost.
3. Documentation: Keep detailed documentation of the backup and restore process, including any custom configurations or plugins used in Jenkins.

By following these steps and suggestions, you can ensure the safety and reliability of your Jenkins server, minimizing downtime and protecting critical data.

Downtime Analysis:

• here iam always stopping and starting jenkins service before doing backup or restore activity, but this will cause downtime

To perform Jenkins backups and restores with minimal downtime, consider the following strategies:

1. Use Jenkins Built-In Backup Plugins

• Jenkins Backup Plugin: Install and configure the Jenkins Backup plugin. This plugin allows you to back up Jenkins data without stopping the service.
• ThinBackup Plugin: Another option is the ThinBackup plugin, which provides incremental backups and can operate while Jenkins is running.

2. Use the Jenkins Safe Mode

• Safe Mode: Before taking a backup, put Jenkins in safe mode, which prevents new builds from starting and pauses ongoing builds without stopping the Jenkins service. This can help ensure consistency in the backup process without full downtime.

  curl -X POST "http://localhost:8080/safeRestart" --user admin:password

  After the backup is complete, you can exit safe mode.

3. Snapshot the Jenkins Environment

• Virtual Machine Snapshots: If Jenkins is running on a VM, create a snapshot of the entire VM. This approach allows you to restore Jenkins to its previous state without stopping the Jenkins service.
• Docker Containers: If Jenkins is running in a Docker container, use Docker snapshots or volumes to back up data without downtime.

4. Use a Jenkins High Availability (HA) Setup

• Jenkins HA: Implement a Jenkins high availability setup with a master-slave configuration or use Jenkins in a clustered environment. This allows one Jenkins instance to handle the backup while others continue to run builds.
• Jenkins Operations Center: Use Jenkins Operations Center to manage multiple Jenkins instances and perform backups from a central point.

5. Perform Incremental Backups

• Incremental Backups: Instead of taking full backups every time, perform incremental backups that only capture changes since the last backup. This reduces the backup window and minimizes impact on Jenkins operations.

6. Database Backup and Restore

• Separate Databases: If Jenkins is using an external database for storing build data and configurations, back up the database separately. This way, you can restore Jenkins from the database backup without stopping Jenkins.

Example Using Jenkins Backup Plugin

1. Install the Backup Plugin:

   • Go to Manage Jenkins > Manage Plugins.
   • Search for the Backup Plugin or ThinBackup Plugin and install it.

2. Configure the Backup Plugin:

   • Go to Manage Jenkins > Configure System.
   • Configure the backup settings according to your needs (e.g., backup frequency, storage location).

3. Run Backups:

   • The plugin will perform backups based on the configured schedule without stopping the Jenkins service.

By using these methods, you can significantly reduce or eliminate downtime during backup and restore operations for Jenkins.