Introduction

Here we will see how to persist Jenkins data with .tar on a containerized jenkins.

Notes about terraform

• Don't forget to change terraform.tfvars to set vm admin username, storage account key etc;

• The Virtual machines password will NOT be on the output, instead they can be securely found in the terraform.tfstate file.

Steps

Note that in this example we will backup to an Azure Storage Account

• On the Vm running the Jenkins Docker container, run the below command to tar and zip the volume which Jenkins uses to store its data,

in our case /var/jenkins_home:

docker run --cidfile=id.tmp --volumes-from <container_id> ubuntu tar -cO /var/jenkins_home | gzip -c > volume.tgz

this can take some time to complete

you need to have docker installed

this will also create a log file

it runs on ubuntu docker image

volume.tgz is the name that of the final .tar file

• Now you can upload the file wherever you want, in our case, we will upload to an azure storage account.

To do this, with azure cli installed, run:

az storage blob upload --account-name storage-account-name --container-name container-name --name volume.tgz --file volume.tgz --auth-mode key

you can also use --auth-mode login if you will

• Now, on another machine:

pull the Jenkins docker image:

docker pull jenkins/jenkins

this will pull the latest jenkins docker image

Run the docker image:

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

this will run a container named jenkins, based on jenkins/jenkins image, on detached mode, with ports 8080 and 50000 open. Also, we are defining the volume, this volume will be where the jenkins data will be stored.

Access the container on root:

docker exec -u 0 -it <container_id> bash

• With azure cli installed:

download the tar file with:

az storage blob download --account-name storage-account-name --container-name container-name --name volume.tgz --file volume.tgz --auth-mode key

you can also use --auth-mode login if you will

Now, extract it:

tar -xzvf volume.tgz

this will extract the tar file

• We already specified the jenkins_home PATH on the .tar command, so it will replace all jenkins data with the archived jenkins data on the .tar file.

Restart the container:

docker restart <container_id>

Final Result

Now when you access Jenkins, it will have all the data at backup run time and prompt you to log in: