Deploy the mongodb-replicaset helm chart on Kubernetes

Question

Pulumi · Accepted Answer

To deploy the `mongodb-replicaset` Helm chart on Kubernetes using Pulumi, you will create a Pulumi program in TypeScript. This program will use the `@pulumi/kubernetes` package to interact with your Kubernetes cluster.

Below, I will provide a step-by-step guide that will walk you through the process of creating a Pulumi stack in TypeScript that deploys the `mongodb-replicaset` Helm chart.

### Prerequisites

1. A configured Kubernetes cluster where you can deploy the Helm chart.
2. The `kubectl` command-line tool connected to your cluster.
3. Pulumi CLI installed on your local machine.
4. Node.js installed on your local machine to run TypeScript programs.

### Step 1: Set up your project

Initialize a new Pulumi project on your local machine by running `pulumi new typescript` in your terminal. This will create a new directory with a template TypeScript project.

### Step 2: Install the necessary dependencies

You need to install the `@pulumi/kubernetes` package, which allows you to interact with your Kubernetes cluster from your Pulumi program.

```shell
npm install @pulumi/kubernetes
```

### Step 3: Write your Pulumi program

Now let's write your Pulumi TypeScript program. Create a new file named `index.ts` and populate it with the following code:

This program defines a single resource: a Helm chart for `mongodb-replicaset`. The `Chart` resource from the `@pulumi/kubernetes` package represents a Helm chart in code which will be deployed on your Kubernetes cluster.

The `mongodb-replicaset` chart is assumed to be hosted in a Helm repository where Pulumi can fetch it. You can optionally customize the chart by specifying different parameters inside the `values` argument.

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

const mongoDbReplicaSet = new k8s.helm.v3.Chart("mongodb-replicaset", {
    // You can specify the repository that hosts the 'mongodb-replicaset' Helm chart.
    // If the Helm chart is already added to your Helm CLI's repository list, you
    // don't need to specify the `repo` argument.
    repo: "the-repo-where-mongodb-replicaset-is-hosted",
    chart: "mongodb-replicaset",
    // Specify the version of the Helm chart you want to deploy.
    version: "the-version-of-the-mongodb-replicaset-chart",
    // You can provide values to customize the Helm chart's default
    // configuration. For example, you can change the replica count,
    // resource requests/limits, image version, etc.
    values: {
        replicas: 3,
        // Add additional values as needed.
    },
    // The namespace where you want to deploy your Helm chart. If you don't
    // specify a namespace, Pulumi deploys it to the default namespace.
    namespace: "mongodb-namespace",
});

// Export the base URL for the MongoDB replica set, which can be used to connect
// to MongoDB from an application in your Kubernetes cluster. The exact command
// depends on the Helm chart specification.
export const mongoDbUrl = mongoDbReplicaSet.getResourceProperty("v1/Service", "mongodb-replicaset", "status");
```

### Step 4: Deploy your Pulumi stack

Run the following commands in your terminal to log in to the Pulumi service and deploy your stack to your Kubernetes cluster:

```shell
pulumi login
pulumi up
```

These commands will compile your TypeScript program to JavaScript, prompt you to review the changes, and apply the changes to your cluster.

### Step 5: Verify the deployment

After the deployment is successful, check that the `mongodb-replicaset` pods are running:

```shell
kubectl get pods -n mongodb-namespace
```

You should see a number of pods equal to the `replicas` value you've configured, all in a running state.

### Documentation Reference

For further details regarding the deployment of Helm charts and management of Kubernetes resources with Pulumi, you can refer to the official Pulumi documentation:

- Pulumi Kubernetes Provider: [Kubernetes Helm Charts](https://www.pulumi.com/docs/reference/pkg/kubernetes/helm/v3/chart/)
- Pulumi Getting Started with Kubernetes: [Getting Started with Kubernetes](https://www.pulumi.com/docs/get-started/kubernetes/)

The code above assumes you have a basic understanding of how Helm charts are organized and the values they accept. You would typically customize the chart by altering the `values` passed to it, which override the default settings that the chart provides. The specific values and their possible settings will depend on the particular `mongodb-replicaset` Helm chart you are using.

Please replace `"the-repo-where-mongodb-replicaset-is-hosted"` and `"the-version-of-the-mongodb-replicaset-chart"` with the actual repository URL and chart version you wish to deploy. If these values are unspecified, Helm will use the chart's default repository and the latest version.