Deploy the deploy-flask helm chart on Google Kubernetes Engine (GKE)

Question

Pulumi · Accepted Answer

To deploy a Flask application using the Helm chart to Google Kubernetes Engine (GKE), you'll need to follow a series of steps which involve setting up a GKE cluster, installing Helm in your Pulumi program, and finally deploying the Flask application using a Helm chart.

Below is a Pulumi program written in TypeScript that illustrates these steps. Before you run this program, ensure that you have the necessary prerequisites:

1. Pulumi CLI installed and configured.
2. Access to a Google Cloud Platform (GCP) account with necessary permissions to create resources.
3. The GCP SDK configured to authenticate with your GCP account.

### Detailed Explanation:

1. **Import Modules**: Start by importing necessary Pulumi libraries and GCP modules.
2. **Create a GKE Cluster**: Define a GKE cluster resource. You'll need to choose a name and provide the configuration required for your cluster. This includes specifying the node count, machine type, and the GCP zone where you want to deploy the cluster.
3. **Install Helm**: Use Pulumi's Helm library to install and configure Helm in your program. Helm is a package manager for Kubernetes, which simplifies the deployment and management of applications.
4. **Deploy Flask with Helm**: Define a Helm chart resource that points to the Flask Helm chart. Provide the settings for your Flask application, such as the service type and any other configurations you may need.

Now, let's create the Pulumi program in TypeScript:

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

// Create a GKE cluster.
const cluster = new gcp.container.Cluster('flask-cluster', {
  initialNodeCount: 2,
  minMasterVersion: 'latest',
  nodeVersion: 'latest',
  nodeConfig: {
    // Change machine type based on your needs
    machineType: 'n1-standard-1',
    // Change the zone based on your preferences or omit the zone for a default
    zone: 'us-central1-a',
    // Add OAuth scopes if your application needs specific GCP APIs.
    oauthScopes: [
      'https://www.googleapis.com/auth/cloud-platform',
    ],
  },
});

// Export the Kubeconfig to access the GKE cluster.
export 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 using the generated kubeconfig.
const k8sProvider = new k8s.Provider('k8s-provider', {
  kubeconfig: kubeconfig,
});

// Install and configure Helm.
const helm = new k8s.helm.v3.Chart('flask-chart', {
  chart: 'flask',
  // Replace this with the repository that contains your Flask Helm chart.
  // For example, you might need to use a chart repository such as 'stable'
  // with the appropriate name and version.
  fetchOpts: {
    repo: 'http://your-helm-chart-repository/',
  },
  // Customize your Flask application settings here.
  // For instance, you can modify the service type to be LoadBalancer if you
  // want an external IP to access your app.
  values: {
    service: {
      type: 'ClusterIP',
    },
  },
}, { provider: k8sProvider });

// Export the resources.
export const clusterName = cluster.name;
export const helmReleaseName = helm.resourceNames;
```

To execute this Pulumi program:

1. Save the code to a file named `index.ts`.
2. Run `pulumi up` to create the resources. Pulumi will show you a preview of the resources that will be created and prompt you for confirmation before proceeding.
3. After successful deployment, Pulumi will output the `kubeconfig` needed to access your GKE cluster along with the `clusterName` and the deployed Helm release name `helmReleaseName`.

Remember, the provided code is a template. You'll need to specify the correct Helm chart repository that holds your Flask application's chart or use a public one if available. Modify the `values` property under the `helm` declaration as needed to match the configuration options for your chart.