Viacep Wrapper

Viacep Wrapper is an API wrapper built with Golang used to find address by zipcode (Brazil only). This project was developed for study purposes.

Architecture

Let's imagine the following challenges to face:

• we have a 3rd party API that provides us with the postal code service
• we need to isolate our domain from changes in that service
• we need to provide all our internal applications with a centralized service that delivers CEP (anti-corruption layer?)

Based on the problems listed above, I created the container diagram below (C4 Model) to exemplify the adopted architecture:

Project structure

Well, for now, let's just focus on the ViaCep Wrapper API. Although the project itself is very simple, I tried to apply the concepts of Hexagonal Architecture (Ports and Adapters) and the principles of SOLID, such as inversion of control and dependency injection.

NOTE: To develop the api layer and expose the application routes I chose the Fiber framework [https://gofiber.io].

src
 |__adapters
 |  |__api
 |
 |__internal
    |__application
    |__domain

How to test it?

NOTE: before executing the commands below, make sure that Go has been installed correctly [https://go.dev/doc/install].

After clone this repo and inside the 'src' directory run the command:

go run main.go

Sending a command-line request using cURL:

Request

curl http://127.0.0.1:8080/api/find-address-by-zipcode/04543900 \ -H "Accept: application/json"

Response:

{
    "message":"",
    "data": {
        "AddressLine1":"Avenida Presidente Juscelino Kubitschek",
        "AddressLine2":"Vila Nova Conceição",
        "AddressLine3":"1830",
        "City":"São Paulo",
        "State":"SP",
        "Country":"Brazil",
        "ZipCode":"04543-900"
    }
}

If you don't have familiarity with cURL you can use browser to see the response from API: