MyBanking: Simple CRUD App with Python, Flask, MySQL

Exchange service API.

MyBanking app has a REST API that exposes 2 endpoints:

• grab_and_save: Accepts a currency name (3 letter code) and an amount (max 24 digits precision with 8 digits for decimals) through POST requests, calls Open Exchange Rate API to get the rate of the currency against USD in order to convert the amount into USD and saves everything into a database (the currency name, the amount, the rate of the currency against USD and the amount converted into USD).
• last: Returns the latest records from the database, depending on the request query string from GET requests. If it receives a currency name, it will return the latest record for that currency, if it receives a number, it will return the latest n records from the database, and if it receives both, it will return the latest n records for the currency.

NOTE Actually there are more endpoints exposed, but they use the rendering feature Flask provides. Only the ones above return data in a json format (as the challenge specified). I chose this approach in order to make the frontend development part easier (since it wasn't the purpose of the challenge).

Running the App

Prerequisites

• docker
• docker-compose
• MySQL

How To Run

1. Change $MY_IP from mybanking/instance/config.py with the IP address of your wireless or wired interface (run ifconfig)
2. cd mybanking
3. sudo docker-compose up --build

Testing

The endpoints can be tested both from UI and curl.

UI Testing

Paste in a web browser the following URL: http://127.0.0.1:5000/ to view the UI. On the right side there are two links: My Exchanges and Filter Exchanges.

In order to test the grab_and_save endpoint, click on My Exchanges and then on Exchange Amount button (from the bottom of the page). A form will be displayed and upon submit, a new exchange will be created. All the exchanges from the database are displayed on My Exchanges page.

In order to test the last endpoint, click on Filter Exchanges page. Use the form in order to filter the exchanges. Upon submit, the filtered exchanges will be displayed below the form.

CURL Testing

For the grab_and_save endpoint, use the following command:

curl -i --header "Content-Type: application/json" --request POST --data '{"currency":"EUR","amount":1234.5}' http://127.0.0.1:5000/grab_and_save

For the last endpoint, use one of the following commands:

curl -i -X GET "http://127.0.0.1:5000/last?currency=EUR&number=10"

curl -i -X GET "http://127.0.0.1:5000/last?currency=EUR"

curl -i -X GET "http://127.0.0.1:5000/last?number=5"