Deploy the multitenant helm chart on Google Kubernetes Engine (GKE)

Question

Pulumi · Accepted Answer

To deploy a multi-tenant Helm chart on Google Kubernetes Engine (GKE), we will follow several steps:

1. **Create a GKE cluster**: This involves defining the configuration for the Kubernetes cluster such as the node count, machine type, and other properties.

2. **Install Helm**: Helm is a package manager for Kubernetes, which allows you to define, install, and upgrade even the most complex Kubernetes applications. Helm charts help you define, install, and upgrade even the most complex Kubernetes application.

3. **Deploy the Helm chart**: After the cluster is up and Helm is set up, we'll deploy the Helm chart by specifying the chart and any custom values we may need for our deployment.

In the following Pulumi program in TypeScript, we'll use the `gcp.container.Cluster` resource to create a GKE cluster and the `helm.v3.Chart` from Pulumi's Helm package to deploy a multi-tenant application represented by a Helm chart.

To get started, you must have Pulumi installed, configured to use GCP, and set up with the required GCP credentials. You should also have Node.js installed to run the TypeScript program.

Let's define the required resources:

```typescript
import * as pulumi from '@pulumi/pulumi';
import * as gcp from '@pulumi/gcp';
import * as k8s from '@pulumi/kubernetes';
import * as helm from '@pulumi/kubernetes/helm/v3';

// Create a GCP GKE cluster
const cluster = new gcp.container.Cluster('gke-cluster', {
    // Note: The `initialNodeCount`, `nodeVersion` and other properties below
    // should be adjusted according to your requirements.
    initialNodeCount: 1,
    minMasterVersion: 'latest',
    nodeVersion: 'latest',
    nodeConfig: {
        machineType: 'n1-standard-1', // Change machine type based on your needs.
        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"
        ],
    },
});

// Obtain the KubeConfig after cluster creation to interact with the cluster
const kubeConfig = pulumi.
    all([cluster.name, cluster.endpoint, cluster.masterAuth]).
    apply(([name, endpoint, masterAuth]) => {
        const context = `${gcp.config.project}_${gcp.config.zone}_${name}`;
        return `apiVersion: v1
clusters:
- cluster:
    certificate-authority-data: ${masterAuth.clusterCaCertificate}
    server: https://${endpoint}
  name: ${context}
contexts:
- context:
    cluster: ${context}
    user: ${context}
  name: ${context}
current-context: ${context}
kind: Config
preferences: {}
users:
- name: ${context}
  user:
    auth-provider:
      config:
        cmd-args: config config-helper --format=json
        cmd-path: gcloud
        expiry-key: '{.credential.token_expiry}'
        token-key: '{.credential.access_token}'
      name: gcp
`;
    });

// Create a Kubernetes provider instance that uses our GKE cluster's kubeconfig.
const k8sProvider = new k8s.Provider('gkeK8s', {
    kubeconfig: kubeConfig,
});

// Deploy the multi-tenant Helm chart using the Helm Release resource.
const multiTenantChart = new helm.Chart('multi-tenant-app', {
    chart: 'your-helm-chart-name', // Replace with the name of your Helm chart
    version: 'your-chart-version',  // Specify the chart version, if desired
    namespace: 'your-target-namespace', // Replace with your namespace, if needed
    values: {}, // Provide specific values for the Helm chart
    // You can specify detailed configuration for your multi-tenant setup here.
}, { provider: k8sProvider });

// Export the cluster's name and kubeconfig
export const gkeClusterName = cluster.name;
export const gkeKubeconfig = kubeConfig;
```

In the above program, we've created a GKE cluster and installed a Helm chart via Pulumi. Adjust the properties for the `gcp.container.Cluster` and the `helm.Chart` as needed for your specific scenario. For example, you may need to specify different machine types, node counts, Helm chart values, or namespace.

Remember to replace `your-helm-chart-name`, `your-chart-version`, and `your-target-namespace` with the actual values of the Helm chart you want to deploy in your multi-tenant GKE environment.

The `kubeConfig` generated will be used to interact with your new Kubernetes cluster. For security reasons, be cautious about where and how you export this information.

Run the Pulumi program using the following commands in your terminal:

```bash
pulumi stack init dev
pulumi up
```
This will prompt you to review and confirm the actions before applying them. After reviewing the planned actions, proceed with the deployment by choosing `yes`.

Once deployment is complete, you can interact with your GKE cluster using `kubectl` by setting the `KUBECONFIG` environment variable to the output of the `gkeKubeconfig` export, or by using the exported values in your CI/CD system.