Using aws elasticache with route53domains

Question

Pulumi · Accepted Answer

To integrate AWS ElastiCache with Route53 domains, you typically need to create an ElastiCache cluster and then create a DNS record in Route53 that points to the ElastiCache endpoint. However, the auto-generated suggestions do not include any Route53-related resources. We'll proceed with creating an ElastiCache cluster and will manually discuss how you could point a Route53 Domain to it.

Here's a Pulumi TypeScript program that will:

1. Create an ElastiCache subnet group.
2. Create an ElastiCache cluster within the subnet group.
3. Assume that you already have a registered domain in Route53 and are able to create a new CNAME record that points to the ElastiCache cluster.

Before the code, here are a few high-level steps of what we're going to do:

- Define an ElastiCache subnet group. ElastiCache instances need to be launched within a subnet group which is a collection of subnets (within a VPC) that can be used with ElastiCache.
  
- Create an ElastiCache cluster which represents the collection of cache nodes in the same network, running the same protocol-compliant cache engine software.
  
- After the ElastiCache resource is created, it will have an endpoint. You can retrieve this endpoint from the AWS Management Console and create a CNAME record in your Route53 hosted zone pointing to it. This isn't directly managed by Pulumi, as it generally involves manual intervention or custom scripts.

Now, let's go over the Pulumi program to set up the ElastiCache cluster:

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

// Create an ElastiCache subnet group
const cacheSubnetGroup = new aws.elasticache.SubnetGroup("my-cache-subnet-group", {
    description: "My ElastiCache subnet group",
    // Ensure these subnetIds are from a VPC that is configured for your requirements
    subnetIds: ["subnet-xxxxxxxx", "subnet-yyyyyyyy", "subnet-zzzzzzzz"], // Replace with your actual subnet IDs
});

// Create an ElastiCache cluster
const cacheCluster = new aws.elasticache.Cluster("my-cache-cluster", {
    // Cluster configuration
    clusterId: "my-cluster", // Name for your cluster
    engine: "redis", // or "memcached", depending on your needs
    nodeType: "cache.t2.micro", // Instance size (find the one that suits your needs)
    numCacheNodes: 1, // The number of cache nodes that the cache cluster should have
    subnetGroupName: cacheSubnetGroup.name, // Reference to the subnet group
    // Security and networking settings (not shown here)
    // You should configure securityGroupIds and other networking settings as required
});

// Output the hostname of the ElastiCache cluster for DNS settings
export const cacheClusterHostname = cacheCluster.cacheNodes.apply(nodes => nodes[0].address);

```

This program will set up the ElastiCache resources within your AWS account once executed with `pulumi up`. You can then take the `cacheClusterHostname`, which is exported at the end of the program, and use it to create a CNAME record in your Route53 hosted zone. This action typically looks something like this:

```typescript
const dnsRecord = new aws.route53.Record("my-dns-record", {
    zoneId: "<your-hosted-zone-id>", // Replace with your actual hosted zone ID
    name: "cache.example.com", // The domain name you want to point to the ElastiCache cluster
    type: "CNAME",
    ttl: 300,
    records: [cacheClusterHostname],
});
```

Please note that the above `aws.route53.Record` resource is not included in the main program but is an illustration of how you'd typically create a DNS record after obtaining the ElastiCache hostname.

Remember to replace the placeholder subnet IDs, cluster configurations, and IID information with your actual AWS environment's configuration. Also, you might need to configure additional properties such as security groups and parameter groups based on your use case and best practices for securing your ElastiCache cluster.