Deploy the postgresql-imagestreams helm chart on Kubernetes

Question

Pulumi · Accepted Answer

To deploy the `postgresql-imagestreams` Helm chart on a Kubernetes cluster using Pulumi with TypeScript, we'll leverage the `@pulumi/kubernetes` package, which enables Pulumi to manage Kubernetes resources directly.

Before we start writing our Pulumi program, let's make sure we understand the components:

1. **Kubernetes**: This is an open-source platform designed to automate deploying, scaling, and operating application containers.
2. **Helm**: Helm is a package manager for Kubernetes that allows you to define, install, and upgrade even the most complex Kubernetes applications using charts.
3. **Helm Chart**: A Helm chart is a package of pre-configured Kubernetes resources.

Here's a step-by-step explanation followed by the TypeScript program:

1. **Import the necessary Pulumi and Kubernetes modules**: We're going to import the `@pulumi/pulumi` and `@pulumi/kubernetes` libraries to utilize Pulumi's infrastructure as code capabilities and interact with our Kubernetes cluster.

2. **Create a new Kubernetes Helm Chart resource**: Using the `Chart` class from the `@pulumi/kubernetes/helm/v3` module, we'll define our Helm chart deployment.

3. **Configure the Helm Chart details**: We'll specify the name of the chart (`postgresql-imagestreams`), and if it's stored in a public helm repository, we may need to provide its URL. In this case, because we're deploying a custom or non-standard chart, we might be required to pass in additional configurations such as the path to the chart or the specific version we intend to deploy.

4. **Deploy the Chart**: Once we define our Helm chart resource with the necessary configurations, running `pulumi up` will instruct Pulumi to execute the deployment to our Kubernetes cluster.

Now, let's create the Pulumi program:

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

// Ensure you have configured Pulumi to use your Kubernetes cluster.
// You can configure the kubeconfig as an environment variable `KUBECONFIG`,
// or using the Pulumi configuration system.

// Instantiate the Kubernetes Helm Chart for postgresql-imagestreams.
const postgresqlImagestreamsChart = new kubernetes.helm.v3.Chart("postgresql-imagestreams", {
    // The `chart` parameter is the name of the chart you want to deploy.
    // If the chart is from a public repository, include details like `repo` and `version`.
    // For a local chart, provide the file path to the directory containing the chart.
    chart: "postgresql-imagestreams",
    // If your chart is hosted in a Helm repository, you can specify it using the `repo` key
    // with the repository URL. For a local chart, you might omit this or use `fetchOpts` to
    // specify the path.
    // Example for a public chart repo:
    // repo: "https://charts.myrepo.com/"
    // If you have chart values that need to be overridden, specify them in the `values` object.
    // values: {
    //   key1: "value1",
    //   key2: "value2",
    // },
    // namespace specifies the Kubernetes namespace to deploy into.
    namespace: "default", // change this to the namespace where you want to install the chart.
}, {
    // This option allows you to point Pulumi at a specific kubeconfig file 
    // if `KUBECONFIG` is not set in your environment.
    // Example:
    // provider: new kubernetes.Provider("k8s-provider", { kubeconfig: "/path/to/kubeconfig" }),
});

// Export the base URL for the deployed PostgreSQL application.
// Note that actual accessible endpoints would depend on the service configuration of the Helm chart.
export const postgreSQLURL = pulumi.interpolate `http://${postgresqlImagestreamsChart.getResourceProperty("v1/Service", "postgresql-imagestreams", "status")}.loadBalancer.ingress[0].hostname`;

```

After writing the above code in a `.ts` file, you would set up Pulumi with your desired Kubernetes cluster (if you haven't done so already), and then run `pulumi up` in your terminal. Pulumi will prompt you with the planned changes and ask for confirmation to apply those changes to your cluster. Confirming the prompt will deploy the PostgreSQL image streams according to the Helm chart specifications.

Remember to replace placeholders with actual values where needed, such as the chart location info (`repo`/`versions`/`fetchOpts`) and Kubernetes `namespace`. If the Helm chart you are using needs specific configurations, make sure to set them in the `values` object within the chart definitions.

This process will result in a running PostgreSQL instance on your Kubernetes cluster, managed by Pulumi through the Helm chart.