weather-exercise

This was a interview take home project

Request

Write an http server that uses the Open Weather API that exposes an endpoint that takes in lat/long coordinates. This endpoint should return what the weather condition is outside in that area (snow, rain, etc), whether it’s hot, cold, or moderate outside (use your own discretion on what temperature equates to each type).

The API can be found here:https://openweathermap.org/api. Even though most of the API calls found on OpenWeather aren’t free, you should be able to use the free “current weather data” API call for this project. First, sign-up for an account, which shouldn’t require credit card or payment information. Once you’ve created an account, use https://openweathermap.org/faq to get your API Key setup to start using the API.

Implementation

This is broken into three basic parts: http server (server/), domain layer (domain/), and weather service (repo/).

HTTP Server

Very basic setup. It only has the single route. If this service was meant to be RESTful, obviously we would organize the single route into an appropriate path. There's two example middleware: logging and authentication. Authentication just passes through at the moment, but would be simple to implement. The logging middleware assigns a logger to the request context and ties a request ID to it. This helps with monitoring, and debugging. It could easily be extended to contain much more information on incoming and outgoing requests.

Domain

The domain service simply remaps the weather service data into the out going data. Obviously if we had business logic, this is where we would do that.

Weather Service

Basic client for interacting with the Open Weather service. Again very simple handling here.

Configuration

Configuration is handled purely with environment variables:

Env Var	Required	Description	Default
WEATHER_ADDRESS	No	Address for the http server to listen on	0.0.0.0
WEATHER_PORT	No	Port for the http server to listen on	80
WEATHER_READWRITETIMEOUT	No	Read and Write timeout for the server	20s
WEATHER_IDLETIMEOUT	No	Idle timeout for the server	75s
WEATHER_SHUTDOWNTIMEOUT	No	Graceful shutdown time out	20s
WEATHER_LOGLEVEL	No	Zerolog log level	info
WEATHER_OPENWEATHER_APIID	Yes	Open Weather API ID
WEATHER_OPENWEATHER_BASEURL	Yes	Base URL for Open Weather API
WEATHER_OPENWEATHER_TIMEOUT	No	Client timeout for Open Weather connections	5s
WEATHER_AUTHSERVICE_URL	No	Auth service URL	http://some.auth.com

Build and Run

Use standard go build and run commands with cmd/server/main.go

Docker

If you want to run this in a container, make an environment variable file with the required ones. Then build and run:

> docker build --tag "weather-exercise" .
> docker run -p 8080:80 --env-file /path/to/env/file "weather-exercise"

Then connect on port 8080.

NOTES

• We are making the assumption that responses are in JSON.

• There's nothing specifying float precision in the Open weather API, so I used 6 digits as it should get you around the millimeter precision.

• I am assuming this is a service that will be extended. If this was meant to be stand alone, it should be much smaller and more streamlined.