1. Deploy the twitter-app helm chart on Google Kubernetes Engine (GKE)


    Deploying a Helm chart on Google Kubernetes Engine (GKE) using Pulumi involves several steps, which I'll explain in detail. We'll go through:

    1. Creating a GKE cluster: This involves setting up Kubernetes on GCP.
    2. Installing the Helm chart: We'll leverage Pulumi's integration with Helm to deploy twitter-app.

    This program will be written in TypeScript, which is a statically typed superset of JavaScript that compiles to plain JavaScript.

    1. Creating a GKE cluster

    We will use Pulumi's google-native.container/v1beta1.Cluster to create a GKE cluster. The google-native provider allows us to work directly with GCP's Cloud API.

    Here's why we are using these specific resources:

    • google-native.container/v1beta1.Cluster: Represents a Kubernetes cluster in GKE.

    2. Installing a Helm chart

    Once we have the Kubernetes cluster, we can deploy applications on it using Helm charts. Pulumi is capable of working directly with Helm and can be instructed to deploy a chart from a repository.

    • kubernetes.helm.v3.Chart: Pulumi's resource for deploying a Helm chart in a Kubernetes cluster.

    Now, let's write the Pulumi program. Make sure you have Pulumi installed and set up with your GCP credentials.

    import * as pulumi from "@pulumi/pulumi"; import * as gcp from "@pulumi/gcp"; import * as k8s from "@pulumi/kubernetes"; // Create a GKE cluster. const cluster = new gcp.container.Cluster("twitter-app-cluster", { initialNodeCount: 2, minMasterVersion: "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 = 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 cluster from above. const k8sProvider = new k8s.Provider("twitter-app-k8s", { kubeconfig: kubeconfig, }); // Deploy the twitter-app Helm chart. const twitterAppChart = new k8s.helm.v3.Chart("twitter-app", { chart: "twitter-app", version: "0.1.0", fetchOpts: { repo: "http://charts.example.com/", // Use the correct repository URL }, }, { provider: k8sProvider }); // Export the frontend service IP to access the twitter-app export const twitterAppFrontendIp = twitterAppChart.getResourceProperty("v1/Service", "twitter-app", "status") .apply(status => status.loadBalancer.ingress[0].ip);

    What we are doing in the program:

    • We're creating a Cluster resource using GCP's container.Cluster class, which creates a new Kubernetes cluster. We set the initial node count and machine type of the nodes.
    • We export some useful properties such as the cluster name and the kubeconfig, which can be used to interact with the cluster using the kubectl command-line tool.
    • We set up a k8s.Provider, which is Pulumi's way to interact with the Kubernetes cluster. It needs a kubeconfig, so we're passing the one we got from our GKE cluster resource.
    • We deploy the Helm chart by creating a Chart resource under the Kubernetes provider. The chart parameter specifies the name of the Helm chart and fetchOpts.repo indicates the repository where the Helm chart is located.

    FYI: Before deploying this program, you'll need to replace http://charts.example.com/ with the URL of the Helm chart repository that contains the twitter-app chart.

    After writing the code, you can deploy this stack using Pulumi's command line:

    pulumi up

    This command will provision the declared resources in your GCP account. Make sure the Pulumi CLI is configured for the correct GCP project and that you have access rights to create resources.

    Once the deployment is successful, you can access the twitter-app using the external IP address output by Pulumi. Use the pulumi stack output twitterAppFrontendIp command to retrieve it.