Using aws acm with elasticache

Question

Pulumi · Accepted Answer

To create an AWS infrastructure that uses AWS Certificate Manager (ACM) together with Amazon ElastiCache, you would typically be setting up an environment for a secure application that needs to cache data. ACM would be used to handle SSL/TLS certificates for securing connections, and ElastiCache acts as a distributed in-memory cache to enhance the performance of your application.

Here's how the resources link together:

1. **ACM Certificate**: You will provision an SSL/TLS certificate using AWS Certificate Manager. This certificate can be attached to a load balancer or other AWS services that support SSL termination or encryption in transit.

2. **ElastiCache**: Amazon ElastiCache is a fully managed in-memory data store and cache service by AWS. An ElastiCache Cluster or Replication Group, for example, can be used to provide a high-performance caching layer for your application.

Let's construct a Pulumi program in TypeScript that creates a new TLS certificate using ACM and an ElastiCache cluster with Redis:

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

// Create an ACM certificate for a given domain.
// Make sure you have the domain name registered in Route 53 or any other DNS service provider.
const cert = new aws.acm.Certificate("my-cert", {
    domainName: "mydomain.com", // Replace with your domain
    validationMethod: "DNS", // Assuming DNS-based validation
});

// An ElastiCache cluster requires a subnet group.
// If you do not have subnets ready for use, you should create them along with a VPC.
const subnetGroup = new aws.elasticache.SubnetGroup("my-subnet-group", {
    subnetIds: [
        // List of subnet IDs
    ],
});

// Finally, let's create a Redis cluster in ElastiCache
const cluster = new aws.elasticache.Cluster("my-cluster", {
    clusterId: "my-elasticache-cluster",
    engine: "redis",
    nodeType: "cache.m4.large", // Choose the node type appropriate for your use case
    numCacheNodes: 1,
    parameterGroupName: "default.redis3.2", // Or whichever version you need to use
    subnetGroupName: subnetGroup.name,
    tags: {
        "Name": "my-elasticache-cluster",
    },
});

// Export the DNS name of the ElastiCache cluster
export const elasticacheClusterHostname = cluster.cacheNodes.apply(nodes => nodes[0].address);

// Export the certificate ARN
export const certificateArn = cert.arn;
```

Explanation of the program:

1. We import the necessary AWS modules from the Pulumi AWS SDK.
2. We create an ACM Certificate resource, specifying the domain name and the validation method, which in this case is DNS-based.
3. Before we create the ElastiCache cluster, we prepare a subnet group which is a requirement. You need to specify the subnet IDs which should ideally be private subnets within your VPC.
4. With the subnet group ready, we create an ElastiCache Cluster resource with the specified parameters, including the cluster ID, engine type, node type, number of nodes, etc.
5. Lastly, we export the DNS name of the first cache node in the ElastiCache cluster and the ARN of the ACM certificate which can be used in other resources for reference.

Keep in mind that DNS validation requires that you add a CNAME record to the DNS configuration of your domain. This record is provided by ACM after you create the certificate. If you're using AWS Route 53 for DNS, you can automate this process by creating `aws.route53.Record` resources in Pulumi.

This program assumes you have already configured Pulumi with appropriate AWS credentials and set up AWS with the necessary permissions to create these resources. If you are not sure of how to achieve this setup, I recommend reading the [Pulumi AWS Setup documentation](https://www.pulumi.com/docs/intro/cloud-providers/aws/setup/).

Please note that the `subnetIds` array needs to be populated with actual subnet IDs from your AWS account, and the`domainName` should be replaced with the domain for which you own and want the ACM certificate. The node type, parameter group name, and other ElastiCache configurations should also be selected based on your application's needs.

To run the above Pulumi program, you would save it to a file with a `.ts` extension, then run `pulumi up` in the terminal from the same directory where the file is located, after installing Pulumi and configuring it to access your AWS account.