Setting up Jenkins on Google Kubernetes Engine

This tutorial shows you how to set up Jenkins on GKE to help orchestrate your software delivery pipeline.

Objectives

• Creating a Kubernetes cluster with GKE.
• Installing Jenkins using Helm.
• Connecting to Jenkins.

Costs

This tutorial uses billable components of Google Cloud, including:

• Compute Engine
• Google Kubernetes Engine
• Cloud Build

Use the Pricing Calculator to generate a cost estimate based on your projected usage. New Google Cloud users might be eligible for a free trial.

Before you begin

1. Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.

2. In the Google Cloud Console, on the project selector page, select or create a Google Cloud project.

   Note: If you don't plan to keep the resources that you create in this procedure, create a project instead of selecting an existing project. After you finish these steps, you can delete the project, removing all resources associated with the project.

   Go to project selector

3. Make sure that billing is enabled for your Cloud project. Learn how to confirm that billing is enabled for your project.

4. Enable the Compute Engine, GKE, and Cloud Build APIs.

   Enable the APIs

Preparing your environment

First, prepare your deployment environment.

1. Activate Cloud Shell. Cloud Shell gives you access to the command line in Cloud Console, and includes Cloud SDK and other tools you need for Google Cloud development. Cloud Shell can take several minutes to provision.

   Activate Cloud Shell

   After the process completes, you'll see the following output:

   Welcome to Cloud Shell! For help, visit https://cloud.google.com/cloud-shell/help.
   

2. Set the default Compute Engine zone to us-east1-d:

   gcloud config set compute/zone us-east1-d
   

3. Clone the sample code, or download the zip file.

   git clone https://github.com/GoogleCloudPlatform/continuous-deployment-on-kubernetes.git
   

   The Git repository contains Kubernetes manifests that you'll use to deploy Jenkins. The manifests and their settings are described in Configuring Jenkins for GKE.

4. Navigate to the sample code directory:

   cd continuous-deployment-on-kubernetes
   

Creating a Kubernetes cluster

You can use GKE to create and manage your Kubernetes cluster.

1. Provision a Kubernetes cluster using GKE. This step can take up to several minutes to complete.

   gcloud container clusters create jenkins-cd \
     --machine-type n1-standard-2 --num-nodes 2 \
     --scopes "https://www.googleapis.com/auth/source.read_write,cloud-platform" \
     --cluster-version 1.15
   

   The extra scopes enable Jenkins to access Cloud Source Repositories and Container Registry.

2. Confirm that your cluster is running.

   gcloud container clusters list
   

   Look for RUNNING in the STATUS column.

   NAME        LOCATION    MASTER_VERSION  MASTER_IP    MACHINE_TYPE   NODE_VERSION  NUM_NODES  STATUS
   jenkins-cd  us-east1-d  1.15.11-gke.15     35.231.8.57  n1-standard-2  1.15.11-gke.15   2          RUNNING
   

3. Confirm that you can connect to your cluster.

   kubectl cluster-info
   

   If you are able to successfully connect to your cluster, Kubernetes component URLs display.

   Kubernetes master is running at https://130.211.178.38
   GLBCDefaultBackend is running at https://130.211.178.38/api/v1/proxy/namespaces/kube-system/services/default-http-backend
   Heapster is running at https://130.211.178.38/api/v1/proxy/namespaces/kube-system/services/heapster
   KubeDNS is running at https://130.211.178.38/api/v1/proxy/namespaces/kube-system/services/kube-dns
   Metrics-server is running at https://130.211.178.38/api/v1/namespaces/kube-system/services/https:metrics-server:/proxy
   

Installing Helm

Use Helm to deploy Jenkins from the repository.

1. Download and install the Helm binary:

   wget https://get.helm.sh/helm-v3.2.1-linux-amd64.tar.gz
   

2. Unzip the file to your local system:

   tar zxfv helm-v3.2.1-linux-amd64.tar.gz
   cp linux-amd64/helm .
   

3. Add yourself as a cluster administrator in the cluster's RBAC so that you can give Jenkins permissions in the cluster:

   kubectl create clusterrolebinding cluster-admin-binding --clusterrole=cluster-admin \
           --user=$(gcloud config get-value account)
   

4. Add the official stable repository:

   ./helm repo add jenkinsci https://charts.jenkins.io
   ./helm repo update
   

5. Ensure Helm is properly installed by running the following command:

   ./helm version
   

   You will see versions appear for the client as v3.2.1:

   version.BuildInfo{Version:"v3.2.1", GitCommit:"fe51cd1e31e6a202cba7dead9552a6d418ded79a", GitTreeState:"clean", GoVersion:"go1.13.10"}
   

Installing Jenkins

You will use a custom values file to configure the Jenkins installation. For details on the configuration, look at the jenkins/values.yaml file.

1. Use the Helm CLI to deploy the chart with your configuration set:

   ./helm install cd-jenkins -f jenkins/values.yaml jenkinsci/jenkins --version 2.6.4 --wait
   

   For more information on configuring the Jenkins installation, visit the Jenkins chart's documentation page.

2. After that command completes, ensure the Jenkins pod goes to the Running state and the container is in the READY state:

   kubectl get pods
   

   You will see 1/1 in the READY column and Running in the STATUS column. It can take a few minutes for Jenkins to complete its initialization.

   NAME                          READY     STATUS    RESTARTS   AGE
   cd-jenkins-7c786475dd-vbhg4   1/1       Running   0          1m
   

3. Set up port forwarding to the Jenkins UI from Cloud Shell:

   export POD_NAME=$(kubectl get pods --namespace default -l "app.kubernetes.io/component=jenkins-master" -l "app.kubernetes.io/instance=cd-jenkins" -o jsonpath="{.items[0].metadata.name}")
   kubectl port-forward $POD_NAME 8080:8080 >> /dev/null &
   

4. Check that the Jenkins Service was created properly.

   kubectl get svc
   

   Example Output:

   NAME               CLUSTER-IP     EXTERNAL-IP   PORT(S)     AGE
   cd-jenkins         10.35.249.67   <none>        8080/TCP    3h
   cd-jenkins-agent   10.35.248.1    <none>        50000/TCP   3h
   kubernetes         10.35.240.1    <none>        443/TCP     9h
   

The Jenkins installation is using the Kubernetes Plugin to create builder agents. They will be automatically launched as necessary when the Jenkins master needs to run a build. When their work is done, they are automatically terminated and their resources are added back to the cluster's resource pool.

Connecting to Jenkins

1. Retrieve the admin password that was automatically created by the Jenkins Helm chart:

   printf $(kubectl get secret cd-jenkins -o jsonpath="{.data.jenkins-admin-password}" | base64 --decode);echo
   

2. To open the Jenkins user interface, click Web Preview in Cloud Shell and click Preview on port 8080.

   

3. Click log in on the top right of the window. Enter admin for the User field and the password value from the previous step for the Password field.

4. Click the log in button.

You now have access to Jenkins and a Kubernetes cluster managed by GKE. To take this solution further, you could use these components in your continuous delivery pipeline.

Cleaning up

After you've finished the tutorial, clean up the resources you created on GCP so you won't be billed for them in the future.

Deleting the project

The easiest way to eliminate billing is to delete the project that you created for the tutorial.

To delete the project:

Caution: Deleting a project has the following effects:

• Everything in the project is deleted. If you used an existing project for this tutorial, when you delete it, you also delete any other work you've done in the project.
• Custom project IDs are lost. When you created this project, you might have created a custom project ID that you want to use in the future. To preserve the URLs that use the project ID, such as an appspot.com URL, delete selected resources inside the project instead of deleting the whole project.

If you plan to explore multiple tutorials and quickstarts, reusing projects can help you avoid exceeding project quota limits.

1. In the Cloud Console, go to the Manage resources page.

   Go to Manage resources

2. In the project list, select the project that you want to delete, and then click Delete.
3. In the dialog, type the project ID, and then click Shut down to delete the project.

Deleting disks

1. In the Cloud Console, go to the Disks page.

   Go to Disks

2. Select the checkbox for your jenkins-home disk.
3. To delete the disk, click Delete.

Deleting instances

To delete a Compute Engine instance:

1. In the Cloud Console, go to the VM instances page.

   Go to VM instances

2. Select the checkbox for the instance that you want to delete.
3. To delete the instance, click Delete.

What's next

• Learn more about Jenkins on GKE best practices.

• Learn about how to configure Jenkins for GKE.

• Learn about how to set up continuous deployment to GKE using Jenkins.

• Try out other Google Cloud features for yourself. Have a look at our tutorials.