Gymshark Coding Challenge

This is split into the following components:

Component	Description
Backend	Written in Go 1.16 and will run as an AWS Lambda function. This function can also be called by an API
Deploy	Terraform scripts to deploy the api and go code to AWS cloud

Backend

All code can be found in the backend/ folder of this repo

Building

Every commit to this repo will trigger a Github Action to build and test the code.

To build/test locally:

cd backend/
go mod tidy
go build .
go test .

Deploy

The deployment is handled through terraform scripts.

Terraform scripts configure the following:

1. Go Lambda with the pack calc deployed
2. Node Lambda used as an authoriser for the API Gateway
3. API Gateway integrated with the pack calc lambda
4. A randomly generated token stored as a secure string in ParamterStore which is used as the auth token

API

The API only supports on endpoint as a POST request.

The API body is JSON and should look like this example:

{
  "items":501, 
  "packSizes": [250,500,1000,2000,5000]
}

Example Request:

curl -X POST --data '{"items":501, "packSizes": [250,500,1000,2000,5000]}' \
 https://jcwz2ki77i.execute-api.eu-west-2.amazonaws.com/calculate-packs -H "Authorization: qD449xM9k0nvK@_f"

The auth token is just an example

Notes/ Considerations

1. Unfortunately, I did not have enough time to implement a frontend as I was learning golang while implementing the backend
2. GitHub Actions have been used to do the following:
   1. Build and Test the Go Lang Code
   2. Terraform script validation (fmt, init and validate)
   3. On a PR merge, a GitHub release is created with the compiled Go code attached
   4. Once a GitHub release is published, a deployment workflow is triggered.
      1. This workflow will handle the deployment of the resources