Deploy the simple-prometheus helm chart on Opensshift

Question

Pulumi · Accepted Answer

To deploy the `simple-prometheus` Helm chart on an OpenShift cluster using Pulumi, you'll leverage the Pulumi Kubernetes provider. This provider allows you to write infrastructure as code that interacts with Kubernetes resources, including Helm charts.

Below is a Pulumi TypeScript program that performs the following actions:

1. Imports the necessary Pulumi libraries.
2. Initializes a Helm chart resource which points to the `simple-prometheus` Helm chart.

This program assumes that you have already set up OpenShift and configured `kubectl` to connect to your OpenShift cluster.

Before running this Pulumi program, ensure you have installed Pulumi and set up your OpenShift cluster. You should also have your `kubeconfig` file ready, as Pulumi uses it to communicate with your cluster.

Here is the detailed Pulumi program:

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

// Define the Helm chart from a remote repository.
// Replace VERSION with the specific chart version you want to deploy.
const prometheusChart = new k8s.helm.v3.Chart('simple-prometheus', {
    chart: 'prometheus',
    version: 'VERSION', // specify the chart version
    fetchOpts: {
        repo: 'https://prometheus-community.github.io/helm-charts',
    },
    // Namespace where the chart will be installed
    namespace: 'monitoring',
    // Any specific values you want to override from the default chart values.
    values: {
        // Define values to override here, if necessary.
    },
    // Shows transformations, if you need to perform operations on the
    // resources before they are applied to the cluster.
    // Below is a commented example on how to prefix resource names.
    /*
    transformations: [
        (obj: any) => {
            // Do not attach prefixes to namespaces
            if (obj.kind === "Namespace") {
                return;
            }
            // Attach a prefix to the resource name
            if (obj.metadata) {
                obj.metadata.name = `my-prefix-${obj.metadata.name}`;
            }
        },
    ],
    */
}, { provider: k8sProvider });

// Optional: Export the Helm chart name which could be useful if you are composing
// this deployment with other resources in a larger Pulumi program.
export const chartName = prometheusChart.name;
```

**Description of the Pulumi Resources Used:**

- `@pulumi/kubernetes`: This is the Pulumi Kubernetes provider module. It contains classes and functions to interact with Kubernetes resources, including Helm charts.

- `k8s.helm.v3.Chart`: This class represents a Helm chart resource in Pulumi. It is responsible for deploying Helm charts into a Kubernetes cluster.

**Explanation of Program Components:**

- **Helm Chart Definition**: The `prometheusChart` constant is an instance of the `Chart` resource. It references the `prometheus` chart from the official Prometheus community Helm chart repository. You need to replace `'VERSION'` with the actual version string of the chart you wish to deploy.

- **Namespace**: The `namespace` property specifies the Kubernetes namespace into which the chart will be deployed. This example uses the `monitoring` namespace, but you can change it to a namespace of your choice.

- **Values Override**: The `values` object allows you to provide custom configuration settings that override the defaults in the Helm chart. If you need to change any settings, you can specify them here as key-value pairs.

- **Transformations (Optional)**: If you need to modify the resources generated by Helm chart before they are applied to Kubernetes, you can define a set of transformation functions. The commented `transformations` example shows how you might add a prefix to resource names, for instance.

- **Provider**: The `{ provider: k8sProvider }` argument specifies which K8s provider to use. This variable should refer to an instance of a Kubernetes provider that has been previously configured to point to your OpenShift cluster. If your kubeconfig is set up correctly, you may omit this option, and Pulumi will use the default provider.

- **Export**: The `export` statement is optional. If your Pulumi program is part of a larger infrastructure, you might want to export certain values for use in other parts of your application.

Make sure to replace the `VERSION` placeholder with the correct version of the simple-prometheus chart you wish to deploy. You can find the versions on the [Prometheus Helm Chart Repository](https://prometheus-community.github.io/helm-charts).

To run this program, you need to ensure you have the latest versions of `@pulumi/pulumi` and `@pulumi/kubernetes` packages installed in your project. You can do this by running `npm install` with the appropriate package names. Once you have the Pulumi CLI and your Node.js environment set up, you can use `pulumi up` to deploy this Helm chart to your OpenShift cluster.