feat: run backend locally

[kevin-loftus-dept]

Implement Local Backend Development

Type of Change*

• New feature
• Bug fix
• Documentation update
• Refactoring
• Hotfix
• Security patch
• UI/UX improvement

Description

Currently, testing any backend development means deploying the local code changes up to the development site. This PR implements a local express server that exposes the available endpoints while still utilizing all deployed AWS resources like DynamoDB, SNS, and SQS.

Pointing the local frontend to the local backend just takes running pnpm run local-server in the front-end directory, which sets an environment variable USE_LOCAL_BACKEND=1. To switch back to point to the deployed dev API, simply use pnpm run nuxt-dev instead.

All requests from the local API include a response header X-Easy-Genomics-Backend: local to easily verify where the backend code has been run.

Testing*

I have run the frontend and backend locally and confirmed that the app works correctly and connections to AWS services work as intended.

Impact

This work should enable future backend development to be quicker and easier.

Checklist*

• No new errors or warnings have been introduced.
• All tests pass successfully and new tests added as necessary.
• Documentation has been updated accordingly.
• Code adheres to the coding and style guidelines of the project.
• Code has been commented in particularly hard-to-understand areas.