Using aws eks with cognito

Question

Pulumi · Accepted Answer

Integrating AWS Elastic Kubernetes Service (EKS) with Amazon Cognito provides you with a way to manage authentication for your Kubernetes cluster. Cognito offers user management, which includes sign-up, sign-in, and access control. When using EKS, you can configure your Kubernetes cluster to use an identity provider to authenticate users. With Cognito as this provider, you can leverage Cognito User Pools to integrate with Amazon EKS through Kubernetes role-based access control (RBAC).

Below is a Pulumi program written in TypeScript that sets up an AWS EKS cluster along with a Cognito User Pool and Identity Pool. It configures the EKS cluster to allow authentication via Cognito.

To get started with the implementation, you'll need to install Pulumi and set up your AWS credentials. Once that is done, you can run the Pulumi CLI to create a new Pulumi TypeScript project, and replace the contents of `index.ts` with the following code block.

Here's a broad outline of what we'll do in the program:
1. Set up a new Cognito User Pool to manage users.
2. Create a Cognito Identity Pool that will allow federated identities to access services.
3. Set up an EKS cluster that is integrated with the Cognito Identity Pool.

Let's start with the detailed program in TypeScript:

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

// Create an Amazon Cognito User Pool. This will be used to manage access to the EKS cluster.
const userPool = new aws.cognito.UserPool("eksUserPool", {
    // Define attributes of the user pool here
    // Refer to https://www.pulumi.com/registry/packages/aws/api-docs/cognito/userpool/
});

// Create a User Pool Client. This client will interact with the user pool.
const userPoolClient = new aws.cognito.UserPoolClient("eksUserPoolClient", {
    userPoolId: userPool.id,
    // Client configurations go here
    // Refer to https://www.pulumi.com/registry/packages/aws/api-docs/cognito/userpoolclient/
});

// Create an Amazon Cognito Identity Pool. This pool will provide AWS credentials to federate identities.
const identityPool = new aws.cognito.IdentityPool("eksIdentityPool", {
    allowUnauthenticatedIdentities: false, // Don't allow unauthenticated users
    cognitoIdentityProviders: [{
        providerName: userPool.endpoint,
        clientId: userPoolClient.id,
    }],
    // Further configurations can be defined here
    // Refer to https://www.pulumi.com/registry/packages/aws/api-docs/cognito/identitypool/
});

// Create an EKS cluster.
const cluster = new eks.Cluster("eksCluster", {
    // Define the configurations for the cluster
    // Refer to https://www.pulumi.com/registry/packages/eks/api-docs/cluster/
});

// Here you might set up Kubernetes RBAC roles that allow access based on Cognito credentials.

// For demonstration purposes, we'll create a simple Kubernetes service.
const k8sService = new aws.eks.Service("example", {
    metadata: {
        namespace: "kube-system",
        name: "example",
    },
    spec: {
        ports: [{ port: 80, targetPort: "http" }],
        selector: { app: "example" },
    },
}, { provider: cluster.provider });

// Output the EKS cluster details, including the cluster name and the kubeconfig.
// You can use this kubeconfig to interact with your cluster through kubectl or any
// other Kubernetes tooling.
export const kubeconfig = cluster.kubeconfig;
export const userPoolId = userPool.id;
export const userPoolClientId = userPoolClient.id;
export const identityPoolId = identityPool.id;
```

Here is a walkthrough of this program:

1. The program begins by importing the necessary AWS and EKS modules from Pulumi's libraries.
2. We create a Cognito User Pool using `aws.cognito.UserPool`. This user pool will contain a directory of users that can access your EKS cluster.
3. We create a User Pool Client associated with the User Pool using `aws.cognito.UserPoolClient`. This allows for applications to interact with the user pool for authentication purposes.
4. We set up an Identity Pool using `aws.cognito.IdentityPool`, which will authenticate users and provide them with temporary AWS credentials. We link the identity pool to our user pool and user pool client. It's set not to allow unauthenticated identities, meaning the users must be authenticated through the user pool to access AWS services.
5. We then create a new EKS cluster with `eks.Cluster`. This will set up an EKS cluster in your AWS account with the specific configurations you define.
6. As an example, a simple Kubernetes service is created to demonstrate how Kubernetes workloads can be deployed to the cluster. This would be the place where you would configure the actual workloads you want to run in the EKS cluster.
7. Finally, we export important details like the `kubeconfig` for accessing the EKS cluster, and the IDs of the Cognito pools we've created. This information can be utilized to configure the EKS cluster to use Cognito for authentication and authorize users to access resources.

Keep in mind that this program sets up the resources but does not include the necessary configurations to integrate AWS EKS with the Cognito User Pool for authentication. Integrating them might involve configuring Kubernetes RBAC and AWS IAM roles and policies, as well as working with AWS Identity and Access Management (IAM) roles for service accounts. These are advanced configurations that require understanding of Kubernetes authentication mechanisms in detail.

Once you have the program code ready, you would run `pulumi up` to deploy the infrastructure. Note that managing Kubernetes resources with Pulumi requires `kubectl` to be properly configured to communicate with the EKS cluster, which would be configured once you apply the Pulumi program.