How I Migrated Jenkins to a New Docker Host (With Zero Downtime)

Migrating Jenkins Container from One Host To Another

When you’re managing CI/CD pipelines with Jenkins inside Docker containers, migration between servers can seem daunting. I recently had to move my Jenkins instance from one VPS to another, ensuring no loss of job configurations, plugins, or build history. Here’s how I did it — cleanly, safely, and efficiently.

Caution

• Identify the Jenkins version you are using, it should be the same image on the new host
• Both server should be able to communicate with each other usin SSH

Identity Jenkins Home Directory

On your current server, find the volume used to persist jenkins data. If you are using bind mounts volume try to find the location using following command:

docker inspect jenkins-container-name | grep volume

of if using docker named volume:

docker volume ls

Backup Jenkins Data

Before creating a backup, make sure jenkins server stopped to avoid incosistency:

docker stop jenkins-container-name

Archive the jenkins home data:

• For Bind Mount Volume:

  tar -czvf jenkins_backup.tar.gz /path/of/bind/mount
  

• For a named volume:

  docker run --rm -v jenkins_home:/data -v $(pwd):/backup alpine \
  tar czvf /backup/jenkins_backup.tar.gz -C /data .
  

  Here, we have used a new container using alpine image to create a backup of jenkins docker volume. it will create a jenkins_backup.tar.gz file in your current directory.

Transfer Data to New Server

Copy the backup file to new server using scp:

scp jenkins_backup.tar.gz user@new_host:/path/to/new_host

Restore Data

You can extract data into a directory to use as bind mount or a docker volume. I recommend to use docker named volume it easy to handle persistence data.

• To extract into a directory:

  mkdir -p /var/jenkins_home
  tar -xzvf jenkins_backup.tar.gz -C /var/jenkins_home
  chown -R 1000:1000 /var/jenkins_home
  

• To extract into a docker volume:

  # create docker volume
  docker volume create jenkins_home
    
  # extract data into this volume and fix file permissions
  docker run --rm -v jenkins_home:/data -v /directory_path/of/backup_file/:/backup alpine \
  sh -c "cd /data && tar xzvf /backup/jenkins_backup.tar.gz && chown -R 1000:1000 /data"
  

  What’s happening here?: docker creating a new alpine container using jenkins_home volume, and extracted backup data into that directory and modified the files permission.

Run Jenkins on the New Host

Let’s run the jenkins container on the new host with resorted data volume.

docker run -d --name jenkins -p 8080:8080 -p 50000:50000 -v jenkins_home:/var/jenkins_home jenkins/jenkins:lts

If you are using bind mount, then replace the jenkins_home docker volume with your mount directory.

We are done. With a few careful steps and the power of Docker, migrating Jenkins becomes a repeatable and reliable process. Whether you’re moving to a better host or rebuilding infrastructure, this technique ensures you’re never locked into a single machine.

Thanks for reading.