Deploy the linkerd helm chart on Kubernetes

Question

Pulumi · Accepted Answer

Deploying a Helm chart on Kubernetes with Pulumi is a process that involves setting up the Kubernetes provider, then using the Helm chart component to deploy your chosen chart—in this case, Linkerd, which is a service mesh for Kubernetes.

Below is a Pulumi program in TypeScript that deploys the Linkerd Helm chart on a Kubernetes cluster. It assumes that you have a Kubernetes cluster running and that you've configured `kubectl` to connect to it. Also, make sure your Pulumi CLI is installed and configured for use.

### The Pulumi Program Explained

First, you import the necessary packages for the Pulumi Kubernetes provider and the Helm chart resource.

Using the `helm.v3.Chart` resource, you are able to specify the details for deploying the Linkerd chart. You should specify the `chart` name, optionally the `version`, the `fetchOpts` which can include details such as the `repo` where the helm chart is hosted, any `values` you wish to pass to the Helm chart to customize it, and finally the `namespace` where you want to deploy the Linkerd service mesh.

If the Kubernetes cluster is not managed by Pulumi, you don't need to explicitly create a provider instance—normally Pulumi will automatically use the currently active Kubernetes context as provided by your `kubeconfig` file.

### The Program

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

// Create a Kubernetes Namespace
const linkerdNamespace = new kubernetes.core.v1.Namespace("linkerd-namespace", {
    metadata: {
        name: "linkerd",
    },
});

// Deploy Linkerd Helm Chart
const linkerdChart = new kubernetes.helm.v3.Chart("linkerd-chart", {
    chart: "linkerd2",
    version: "2.11.1", // Use the desired version of Linkerd
    fetchOpts: {
        repo: "https://helm.linkerd.io/stable",
    },
    namespace: linkerdNamespace.metadata.name,
    // If you have custom values, you can specify them using `values`
    // values: {
    //     identity: {
    //         issuer: {
    //             tls: { crtExpiry: "2025-01-01T01:02:03Z" }
    //         }
    //     }
    // },
});

// Export the Linkerd web URL
export const linkerdWebUrl = linkerdChart.getResourceProperty("v1/Service", "linkerd-web", "status")
    .apply(status => `http://${status.loadBalancer.ingress[0].ip}`);

```

This program starts by importing the Pulumi Kubernetes package. Then, it creates a namespace for Linkerd to keep it separated from other applications running in your cluster. Next, it deploys the Linkerd Helm chart using the information provided, fetching it from the official Linkerd Helm repository.

### Running the Program

Save this code in a file named `index.ts`. To run the program, execute `pulumi up` in the command line in the same directory as the file is located. This will prompt Pulumi to perform an update, showing you a preview of the actions that will be taken. If you're satisfied with the plan, proceed with the update. Once the update is completed, if Linkerd is exposed via a LoadBalancer service, the external IP of the linkerd-web service is exported.

**Note**: Make sure you have Pulumi installed and configured alongside `kubectl` for the Kubernetes cluster you want to deploy to.

After deployment, you can manage Linkerd using the `linkerd` CLI or the Kubernetes dashboard as per usual with any Linkerd installation.