This is a simple REST API that provides exchange rates for the specified list of currencies. The exchange rates are obtained from the currencyfreaks.com API and saved in a SQLite database.

Put an API key for the currencyfreaks.com API in the config.ini file:

apikey = your_api_key

or pass it as a command line argument:

./bin/api --apikey your_api_key

or set it as an environment variable:

APIKEY=your_api_key ./bin/api

Correct API key should be put in the config.ini file before building the docker container.

To build and run the docker container:

docker build -t currency-api .
docker run -it --rm -p 8080:8080 currency-api

API will be available at http://localhost:8080/

make && ./bin/api

Will start the API server on port 8080

The configuration file is config.ini in the root of the project - it contains default settings which can be overridden by environment variables or command line arguments:

make && ./bin/api --apikey your_api_key --port 8081 --dbpath /tmp/currency-api.db --currencies UAH,USD,EUR,RON --debug

Full list of configuration options can be listed with make && ./bin/api --help

The database is created in the file specified in the configuration file. The database schema with sample data is created automatically on the first run of the API server.

The API logs all requests to the database. Last 10 logs can be viewed with the /v1/status/ endpoint.

make test

Runs all available tests

/v1/rates/ - get latest exchange rates for the currencies specified in the config file

{
	"date": "2024-04-30 00:00:00",
	"base": "USD",
	"rates": {
		"EUR": 0.933291146848332,
		"RON": 4.642474983710198,
		"UAH": 39.63845919120639,
		"USD": 1
	}
}

/v1/rates/<date>/ - get exchange rates for the specified date (e.g. 2024-04-20)

{
	"date": "2024-04-20 00:00:00",
	"base": "USD",
	"rates": {
		"EUR": 0.8,
		"RON": 4.7,
		"UAH": 39.4
	}
}

/v1/pair/<pair>/ - get exchange rates for the specified currency pair (e.g. UAH-RON)

{
	"date": "2024-04-30",
	"pair": "UAH-RON",
	"rate": 0.11712047033200801
}

/v1/status/ - get the status of the API

{
	"status": "ok",
	"version": "93952c1-main-20240501",
	"config": {
		"port": 8080,
		"dbpath": "file:/tmp/currency-api.db?mode=rwc\u0026_journal_mode=WAL",
		"currencies": "UAH,USD,EUR,RON",
		"interval": 3600,
		"debug": true
	},
	"logs": [
		"2024-05-01 01:45:39 | pair | pair: UAH-RON"
	]
}

Original job interview test task:

1. Obtaining exchange rates on a third-party API (UAH / EUR / USD / RON). (eg: https://currencyfreaks.com/)

   1.1 If there was no exchange rate for the current day, get the exchange rate updated at 12:00

   1.2 Implement saving the exchange rate in the database (Sqlite for start, PostgreSQL for extra points)

2. Implement endpoints:

   2.1. Receiving rates for a specified date (all 4 currencies)

   2.2. Obtaining currency pairs: UAH-USD.

3. Implement validation of requests (dates, currency tickers)

4. Implement API access via API key

5. Implement logging of API requests in the database. Save in the logs - date, type of request (by date / by pair)

6. Use docker for the project.

7. When initializing the server, fill the database with initial data on exchange rates for several dates (any values)