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

Question

Pulumi · Accepted Answer

In order to deploy the Geth Helm chart on Google Kubernetes Engine (GKE), you'll follow a series of steps that include setting up a Kubernetes cluster on GKE, installing and configuring Helm, and deploying the Geth chart. Below is a Pulumi program written in TypeScript that demonstrates how to achieve this. This program uses the `@pulumi/gcp` and `@pulumi/kubernetes` packages to interact with GCP and Kubernetes resources, respectively.

### Prerequisites
- Ensure you have [Pulumi CLI](https://www.pulumi.com/docs/get-started/install/) installed.
- Ensure you have [Google Cloud SDK](https://cloud.google.com/sdk) installed and configured for the desired project.
- Ensure you have [kubectl](https://kubernetes.io/docs/tasks/tools/install-kubectl/) installed to interact with the Kubernetes cluster.
- Make sure you're authenticated with Google Cloud and have set the appropriate project with `gcloud auth login` and `gcloud config set project [PROJECT_ID]`.

Each part of the program is thoroughly commented to help you understand what it does and how it contributes to deploying your Helm chart.

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

// Step 1: Create a GKE cluster. This provides the compute infrastructure for our Kubernetes environment.
const cluster = new gcp.container.Cluster("geth-cluster", {
    initialNodeCount: 2,
    nodeVersion: "latest",
    minMasterVersion: "latest",
    nodeConfig: {
        // Choose the appropriate machine type for your use case.
        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",
        ],
    },
});

// Step 2: Export the kubeconfig. This is necessary to communicate with the Kubernetes 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
`;
    });

// Step 3: Instantiate a Kubernetes provider with the kubeconfig from the created cluster.
const k8sProvider = new k8s.Provider("gkeK8s", {
    kubeconfig: kubeConfig,
});

// Step 4: Deploy the Geth Helm chart. Helm charts are packages of pre-configured Kubernetes resources.
const gethChart = new k8s.helm.v3.Chart("geth", {
    chart: "ethereum",
    version: "0.0.1", // Use the appropriate chart version.
    fetchOpts: {
        repo: "https://helm.ethereum.org/",
    },
}, { provider: k8sProvider });

// Export the GKE cluster name and Geth service endpoint.
export const clusterName = cluster.name;
export const gethService = gethChart.getResource("v1/Service", "default/geth");
```

### Explanation:
- We start by importing the required Pulumi libraries for working with GCP (`@pulumi/gcp`) and Kubernetes (`@pulumi/kubernetes`).
- We create a GKE cluster using `new gcp.container.Cluster`, specifying the number of nodes and machine type, among other configurations.
- We then create a kubeconfig that Kubernetes command-line tool (`kubectl`) and other clients can use to communicate with the cluster.
- We instantiate a Kubernetes provider for Pulumi using the kubeconfig, which we will use to deploy resources to the GKE cluster.
- We deploy the Geth Helm chart with `new k8s.helm.v3.Chart`. We specify the chart name, version, and repository URL.
- Finally, we export the cluster name and Geth service endpoint to easily retrieve these values after deployment.

To execute this Pulumi program, save the code in a file (e.g., `index.ts`), run `pulumi up` in the terminal from the same directory as your file. Follow the prompts to preview and apply the changes. This will provision the resources in GCP and deploy the Geth Helm chart to your GKE cluster.

Please note that the versions for Geth Helm chart and Kubernetes nodes are placeholders, and you may need to update them according to your specific requirements and the currently available versions.