Simple HTTP server that manages user data. XML and JSON payload types are both accepted.

Functionalities are below:

1. POST /users create new user given user email and name. It will return a created user with a unique system assigned user ID. Additionally, I added the constraint that emails are unique.
2. GET /users/:userID get user data given a system assigned user ID. It will returns saved user data.
3. PATCH /users/:userID update user data given a system assigned user ID. It will allow to change user name only.

As extra, I have added below behaviors to the API:

• basic rate limiting of 30 req/min.
• autogenerated X-Request-Id which is logged during every request and returned in headers.
• returned 409 for all domain business errors. This is to reduce the number of HTTP status that a consumer has to handle. Also, 400 is returned when there is a validation error with the request. 500 is for unexpected or critical errors.

• Fiber: web framework used, an express like for Go.
• Air: for live reloading of the service during local development.
• Testify: assertion library used.
• go.uuid: for unique id generation.
• validator: for validating using struct tags.

# clone repo
git clone https://github.com/JordyBaylac/user-management-service.git -b main

# install dependencies
go get ./...

# build, test and run
go build -v ./...
go test -v
go run main.go

# make sure api is working
curl --request GET --url http://localhost:8080/health

## (optional) for live reloading

# install air
curl -sSfL https://raw.githubusercontent.com/cosmtrek/air/master/install.sh | sh -s -- -b $(go env GOPATH)/bin

# run
air

# if error 'air: command not found', then add to PATH and run again
export PATH=$PATH:$(go env GOPATH)/bin

curl --request POST \
  --url https://jbaylac-user-management-svc.herokuapp.com/users \
  --header 'Content-Type: application/xml' \
  --data '<?xml version="1.0" encoding="UTF-8"?>
<user>
  <name>Neymar</name>
  <email>[email protected]</email>
</user>'

curl --request GET --url https://jbaylac-user-management-svc.herokuapp.com/users/:userID

curl --request PATCH \
  --url https://jbaylac-user-management-svc.herokuapp.com/users/:userID \
  --header 'Content-Type: application/json' \
  --data '{
	"name": "Neymar da Silva Santos Junior"
}'

This solution embraces decoupling and extensibility through inversion of control. There is a lot of room for improvement, but I think this architecture is easy to maintain, change and evolve with new requirements.

• api/ package is the interface of this service. It's where the http server is configured (routes, middlewares, etc)
• user/ it is a domain specific package that contains business regarding the management of users.

• pentest the api.
• implement persistence storage with a real database.
• implement a custom error handler.
• improve error response model and add codes to business errros.
• add swagger generation for the api.
• add correlation id for distributed tracing.
• add structured logging.
• add metrics.
• refactor project layout to a more conventional one.
• authenticate calls, so that updating a user is only allowed to the creator.
• integrate with a configuration as a service to get secrets and other configs per environment.
• run performance tests, pprof and check race conditions.