set up serverless Aurora CDK database

[AnJuHyppolite]

Description

This PR resolves Configure Aurora Serverless v2 PostgreSQL by implementing Infrastructure as Code (IaC) for an AWS Aurora Serverless v2 PostgreSQL database.

Approach

Using AWS Cloud Development Kit (CDK) and TypeScript:

• Referenced the existing dev VPC (will update to prod VPC once PR is approved and production deployment schedule is set)
• Created supporting resources: subnet group, security group, and Aurora cluster
• Exported VPC and security group for use in API stack (lambdas)
• Updated FeedbackApiStack to accept shared vpc and securityGroup from FeedbackDbStack
• Wrote tests to validate mocked VPC, creation of resources, and configuration settings
• Used cdk synth to generate and validate CloudFormation output

AWS Resource Documentation

• Work with the AWS CDK in TypeScript
• How to create a CDK app
• Define an AWS Virtual Private Cloud
• Create an RDS DB subnet group
• Create an Amazon EC2 security group within a VPC
• Create a clustered database
• AWS CDK Test Assertions

Steps to Test

1. Run npm install to install dependencies.
2. Run npm run synth:dev to synthesize the CDK app into a dev CloudFormation template.
3. 2. Run npm run deploy-db:dev to deploy the dev database AWS.
4. Verify synthesized template includes VPC, subnet group, security group, and Aurora cluster.

To check deployment (in AWS Console):

1. Search for/Go to CloudFormation.
2. Choose your AWS region (e.g., us-east-1) at the top-right.
3. Look for a stack named FeedbackDbStack.
4. Confirm its status is ✅ CREATE_COMPLETE.

Notes

• Deployment requires AWS account authorization due to costs; awaiting leadership approval
• Once PR is approved, we can:
  • deploy to the dev account
  • merge PR into dev

[jachan]

Left my 2 cents on Case's boulder as a comment on the conversation. TLDR I think it should be refactored to use the same App, but I can see why you'd keep resources in their own stack. Also had some questions about the config and why public subnets are necessary here. Great work on your first CDK PR though! It's great to see more IaaC here at the Office <3

[ezhangy]

Thanks so so much for all your work here, and refactoring to make the db part of the same stack as the API!

Left several comments: some [dust/questions] that are more for my own understanding, and some [pebbles] for modifications I think we should make to the stack based on my understanding.

No one piece of feedback I had felt like it rose to the level of a [boulder], but since there are multiple potential changes here, I'd appreciate a chance to get a look over again before you merge!

[jachan]

Seems like a good starting point! Left a comment about the .gitignore that should be resolved before merge.

[ezhangy]

great work!! left some comments about removing the security groups and the VPC for this iteration before we have the public subnet set up, let me know if you have any questions

[ezhangy]

looks good to me! a couple of very minor dusts, no need to ask for a re-review before merging!

so excited to see this PR cross the finish line, really great work here! 🎉