Deploy the cronjob-backup-jenkins helm chart on Google Kubernetes Engine (GKE)

Question

Pulumi · Accepted Answer

To deploy a cronjob that backs up Jenkins using a Helm chart on Google Kubernetes Engine (GKE), we'll perform several steps using Pulumi. The process involves the following key tasks:

1. Create a GKE cluster where our Jenkins and the backup cronjob will run.
2. Install the Helm chart for Jenkins, if not already done.
3. Deploy the `cronjob-backup-jenkins` Helm chart to set up the backup process.

We'll create a Pulumi program that performs these steps. Pulumi allows us to define our infrastructure as code using familiar programming languages, such as TypeScript, which we will use here.

Here's a detailed breakdown of each step in TypeScript:

### Prerequisites

Make sure you have installed Pulumi and configured it to use GCP. You will also need `kubectl` installed to interact with the cluster once it's up, and Helm to manage chart deployments.

### Step 1: Create a GKE Cluster

First, we need a Kubernetes cluster on GKE where we can deploy Jenkins and the backup cronjob. Pulumi makes it easy to provision a GKE cluster using the `@pulumi/gcp` package.

### Step 2: Deploy Jenkins using Helm

After the cluster is up, we can use Pulumi's `@pulumi/kubernetes` package to deploy Jenkins to the cluster using its Helm chart. The Helm chart handles the Kubernetes deployment, service, and other necessary resources.

### Step 3: Deploy the Backup CronJob using Helm

Finally, we need to define and deploy the backup cronjob. Assuming that there is a Helm chart called `cronjob-backup-jenkins` which sets up a Kubernetes `CronJob` to backup Jenkins, we'll deploy that to our cluster as well.

Below is the full Pulumi program in TypeScript:

```typescript
import * as gcp from "@pulumi/gcp";
import * as k8s from "@pulumi/kubernetes";

// Step 1: Provision the GKE cluster.
const cluster = new gcp.container.Cluster("pulumi-gke-cluster", {
    initialNodeCount: 2,
    minMasterVersion: "latest",
    nodeVersion: "latest",
    nodeConfig: {
        machineType: "n1-standard-1",
        oauthScopes: [
            "https://www.googleapis.com/auth/compute",
            "https://www.googleapis.com/auth/devstorage.read_only",
            "https://www.googleapis.com/auth/logging.write",
            "https://www.googleapis.com/auth/monitoring"
        ],
    },
});

// Export the Cluster name
export const clusterName = cluster.name;

// Export the Kubeconfig to access the cluster with kubectl
export const kubeconfig = cluster.name.apply(name => {
    const cluster = gcp.container.getCluster({
        name: name,
        location: cluster.location,
    });

// Step 2: Deploy Jenkins via Helm Chart
const jenkinsChart = new k8s.helm.v3.Chart("jenkins", {
    chart: "jenkins",
    version: "2.6.4",
    fetchOpts:{
        repo: "https://charts.bitnami.com/bitnami",
    },
}, { provider: new k8s.Provider("gkeK8s", { kubeconfig }) });

// Step 3: Deploy the backup cronjob via Helm Chart
const backupCronJobChart = new k8s.helm.v3.Chart("backup-cronjob", {
    // Replace with the actual chart name and version for the cronjob-backup-jenkins Helm chart
    chart: "cronjob-backup-jenkins",
    version: "1.0.0",
    // Replace with the actual repository URL or local path to the Helm chart for cronjob-backup-jenkins
    fetchOpts:{
        repo: "http://your-helm-chart-repository.com",
    },
    // Define any values we need to pass into our CronJob Helm chart here:
    values: {
        schedule: "0 2 * * *", // This cron schedule is an example, adjust it according to your needs
        // Additional configuration for the backup job can go here, if the Helm chart requires it
    },
}, { provider: new k8s.Provider("gkeK8s", { kubeconfig }) });

// Export the Helm release names
export const jenkinsReleaseName = jenkinsChart.releaseName;
export const backupCronJobReleaseName = backupCronJobChart.releaseName;
```

### Explanation

- We created a new GKE cluster with two nodes.
- We defined a provider that uses the generated `kubeconfig`. This provider is necessary for Pulumi to interact with our GKE cluster.
- We deployed Jenkins to our cluster using the Bitnami Helm chart. The chart's repository is specified, and it will install Jenkins with the default values unless you specify your own.
- Then, we deployed the backup cronjob using another Helm chart, `cronjob-backup-jenkins`. You will need to modify the `chart`, `version`, and `repo` attributes according to the actual Helm chart you are using, as well as provide the necessary values for the backup cronjob.
- We exported the `kubeconfig` and Helm release names so that we can interact with our cluster and deployed applications using `kubectl` and check the status of our Helm releases.

Make sure to adjust the `cronjob-backup-jenkins` chart details and repository information according to the actual Helm chart you would like to use for backing up Jenkins.

After writing this program, you should deploy it by running `pulumi up`. Pulumi will provision the infrastructure and apply the configurations as described above. Always review the execution plan that Pulumi provides before confirming the deployment to prevent unintended changes.