pmdcosta/exchange repository overview

⁠Exchange

A golang application that provides the latest exchange rates and recommendations for currency conversion based on https://exchangeratesapi.io/⁠ data.

It compares the latest exchange value against the historic rate for the last week and makes a naive recommendation as to whether this is a good time to exchange money or not.

⁠Endpoints

The rates endpoint returns the current exchange rate in euros for the given currency. It also returns whether now is a good time to exchange money or not.

GET http://{host}/v1/rates/{currency}

{
  "rate": {
    "EUR": 0.9062896502,
    "USD": 1
  },
  "exchange": {
    "recommended": false,
    "reason": "the current exchange value is below the weekly average of 0.907558"
  }
}

⁠Deployment

The repository in integrating with hub.docker.com⁠. Updates to master trigger docker image releases with tag latest and git tags trigger image build with the corresponding tag.

The docker image pmdcosta/exchange can be used to easily deploy the service.

Additionally, the following Make commands are available:

• make test runs unit tests.
• make build builds the docker image.
• make start starts the server locally.
• make stop stops the server.
• make integration-tests starts the server in a container and runs integration tests against it.

⁠Possible Improvements

• Instead of keeping the cache in memory, a Redis instance could be used. Adding a new cache backend is fairly trivial, just requires injecting another client that satisfies the interface in the exchange client.
• The current cache stores the mapping between requests and responses at the http level in the exchangeratesapi.io client. A different strategy would be to store the exchange rates for each day and evaluate if the http requests is needed at all.
• The exchangeratesapi.io client is quite flexible, but the current http server is very specific. More parameters could be added to the http handler, or more endpoints created.