Deploy the exim4 helm chart on AWS EKS

Question

Pulumi · Accepted Answer

To deploy the Exim4 Helm chart on an Amazon EKS (Elastic Kubernetes Service) cluster using Pulumi, you'll need to follow several steps. These steps include creating an EKS cluster and deploying the Helm chart into it.

Here's an outline of the process:

1. **Create an EKS Cluster**: Use the `aws.eks.Cluster` resource to create a new EKS cluster.
2. **Define an IAM Role for EKS**: Define an IAM role using `aws-iam.EKSRole` that EKS will assume to create AWS resources for Kubernetes.
3. **Deploy the Helm Chart**: Use the `kubernetes.helm.sh/v3.Chart` resource to deploy the Exim4 Helm chart to the EKS cluster.

Below is a Pulumi program in TypeScript that implements these steps. Make sure you have Pulumi installed and configured with the appropriate AWS credentials before attempting to run this code.

### Detailed Explanation and Pulumi Program

First, let's write the program to create the EKS cluster:

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

// Step 1: Create an EKS Cluster
const clusterName = "exim4-cluster";

// Set up a VPC for our cluster
const vpc = new awsx.ec2.Vpc("exim4-vpc", {
  numberOfAvailabilityZones: 2,
});

// IAM roles for the node groups
const roleName = `${clusterName}-eksNodeRole`;
const eksRole = new aws.iam.Role(roleName, {
  assumeRolePolicy: aws.iam.assumeRolePolicyForPrincipal({
    Service: "ec2.amazonaws.com",
  }),
});

// Attach the Amazon EKS worker node policy to the role
const workerNodePolicyAttachment = new aws.iam.RolePolicyAttachment(`${roleName}-policyAttachment`, {
  policyArn: "arn:aws:iam::aws:policy/AmazonEKSWorkerNodePolicy",
  role: eksRole,
});

// Create an EKS cluster
const eksCluster = new eks.Cluster(clusterName, {
  vpcId: vpc.id,
  subnetIds: vpc.publicSubnetIds,
  instanceType: "t2.medium",
  roleMappings: [{
    roleArn: eksRole.arn,
    groups: ["system:masters"],
    username: "admin",
  }],
});

// Step 2: Deploy the Helm Chart
// After provisioning the cluster, we can now instantiate a Helm Chart:

const exim4HelmChart = new k8s.helm.v3.Chart("exim4", {
  chart: "exim4",
  version: "0.1.0", // specify the correct chart version
  namespace: "default",
  fetchOpts: {
    // If your Helm chart is in a repository, specify the repo URL
    // repo: "https://example.com/helm-charts",
  },
  // If needed, you can specify values for the Helm chart
  // values: {
  //   key: "value",
  // },
}, { provider: eksCluster.provider });

// Export the cluster's kubeconfig and the Helm chart name.
export const kubeconfig = eksCluster.kubeconfig;
export const chartName = exim4HelmChart.id;
```

In the above program:

- We set up a new VPC for our EKS cluster with 2 availability zones.
- We create an IAM role that EKS will use to manage resources.
- We create the EKS cluster, specifying the VPC, subnets, and instance type for the worker nodes. We also map an IAM role to the Kubernetes `system:masters` group, giving full administrative access to the cluster.
- We deploy the Exim4 Helm chart. You might need to adjust the chart version and the repository URL as required. If the chart requires custom values, you can provide them in the `values` field.

Please replace `"0.1.0"` with the actual version of the Exim4 Helm chart and update the `repo` field with the correct repository containing the Exim4 Helm chart if it's not available in the default Helm chart repositories.

Remember to install the chart into the appropriate namespace and to configure any necessary chart values according to the Helm chart's documentation. If Exim4 needs any specific configurations, those should be specified in the `values` object, commented out in the example.

After you write your Pulumi program, you can deploy it by running `pulumi up` in the same directory as your program. Pulumi will print out the planned changes, and you can confirm the deployment by selecting "yes." After deployment, you can use the exported `kubeconfig` to interact with your EKS cluster using `kubectl`.

Make sure to follow any additional instructions for Exim4 Helm chart configuration, which might require implementing specific Kubernetes resources or configurations for the chart to work correctly.