Version: 2.7

Back up Jenkins on Kubernetes

You can use the instructions on this page to create pre and post backup rules with Portworx Backup, which take application-consistent backups for Jenkins on Kubernetes in production.

Jenkins stores data within a directory known as JENKINS_HOME. Workspaces, plug-ins, jobs, user content and overall configuration exist within this directory and are vital when recovering from various types of failures.

See below for a snippet of what this might look like in a Kubernetes spec file.

...
        volumeMounts:
        - name: jenkins-home
          mountPath: /var/jenkins_home
      volumes:
        - name: jenkins-home
          persistentVolumeClaim:
            claimName: jenkins-data
...

Once you configure a PVC to be mounted at /var/jenkins_home you can use the below guide for pre and post backup rules.

Installation

Prerequisites

note

You should configure a persistent volume for JENKINS_HOME so that the entire directory is backed by a volume to capture all data associated with Jenkins.

These examples assume that the Jenkins CLI is available within the Jenkins pod. You can make sure it's available in the Jenkins pod(s) by running the below command.

kubectl exec <jenkins-deployment-pod> -n jenkins -- /bin/sh -c "wget http://<operations-center-url>:>port-number>/jnlpJars/jenkins-cli.jar -O /var/jenkins_home/cli.jar"

Create rules for Jenkins

Create rules for Jenkins that will run both before and after the backup operation runs:

Create a pre-exec backup rule for Jenkins

Assume the Jenkins deployment has a job called job-1, you will use the pre-exec rule to make sure this job is stopped before taking our snapshot.

note

Stopping a job is not necessary to back up Jenkins. It is used as an example of a pre backup rule. You may run other commands available within the Jenkins pod here as well.

Navigate to Settings > Rules > Add New.
In the Add Rule window, provide the following details:
- Rule name: add a name for your backup rule
- Pod Selector: add the following app label app=jenkins
- Container: ignore this field
- Action: add the following action
```
  java -jar /var/jenkins_home/cli.jar -s http://jenkins:8080 -webSocket -auth username:password stop-builds job-1
```

Create a post-exec backup rule for Jenkins

After your backup is triggered, you can start the build for job-1 again using a post-exec rule. This ensures your job is not running during the backup and is restarted after the backup data is captured.

From the home page, navigate to Settings > Rules > Add New.
In the Add Rule window, provide the following details:
- Rule name: add a name for your backup rule
- Pod Selector: add the following app label appname=jenkins
- Container: ignore this field
- Action: add the following action
```
java -jar /var/jenkins_home/cli.jar -s http://jenkins:8080 -webSocket -auth username:password build job-1
```

Use the rules during backup of Jenkins

During the backup creation process, select the rules in the pre-exec and post-exec drop-down lists:

Once you have populated all the fields of Create Backup window, click Create.

Demo

Watch this short demo of the above information.

Installation​

Prerequisites​

Create rules for Jenkins​

Create a pre-exec backup rule for Jenkins​

Create a post-exec backup rule for Jenkins​

Use the rules during backup of Jenkins​

Demo​