Summary:

The REST APIs are built using Python Flask framework. Docker containers are used for development environment.

It contains the below mentioned endpoints:

• a POST '/grab_and_save'
• a GET '/last'

There are many ways to setup your project folder structure. One is by its function and another is app based structure which means things are grouped bp application. I have used app based approach for this task.

Project Structure (App Based):

FlaskProject/
├── Dockerfile
├── Makefile
├── README.md
├── app/
│   ├── __init__.py
│   ├── api/
│   │   ├── __init__.py
│   │   ├── models.py
│   │   ├── resources.py
│   │   ├── routes.py
│   │   └── schemas.py
│   ├── constants.py
│   ├── db.py
│   ├── settings.py
│   └── utils.py
├── config.py
├── docker-compose.yml
├── entrypoint.sh
├── migrate.py
├── migrations/
│   ├── README
│   ├── alembic.ini
│   ├── env.py
│   ├── script.py.mako
│   └── versions
├── .gitignore
├── requirements.txt
└── run.py

Python extensions used:

• flask - This is a microframework for Python
• flask_restful - This is an extension for Flask that adds support for quickly building of REST APIs.
• flask_script - This is an extension that provides support for writing external scripts in Flask.
• flask_migrate - This is an extension that handles SQLAlchemy database migrations for Flask applications using Alembic.
• flask_sqlalchemy - This is an extension for Flask that adds support for SQLAlchemy. It allows to write ORM queries to operate against database.
• flask_marshmallow - This is an integration layer for Flask and marshmallow (ORM/ODM/framework-agnostic library for converting complex datatypes, such as objects, to and from native Python datatypes. This is used also to Serializing and Deserializing Objects.) that adds additional features to marshmallow.
• mysqlclient - MySQL database connector for Python
• requests - This is a python library to make calls to external APIs

How to start application (using Docker)

• Clone the project using command:

  git clone https://github.com/Rabia23/FlaskProject.git
  

• Go into the project directory:

  cd flask-application
  

• Run the application by the following command:

  make up
  

How to ssh into a Docker containers

• ssh into app container

  make app-shell
  

• ssh into database container

  make db-shell
  root@e27d5a54fbb8:/# mysql -u root -p
  Enter password: root
  mysql> show databases;
  mysql> use testdb;
  mysql> show tables;
  mysql> select * from wallets;
  

Test using CURL

• curl -H "Content-Type: application/json" -X POST -d '{"currency_code": "AED", "requested_amount": 19.7654}' http://127.0.0.1:5000/api/grab_and_save

  {"message": "Data successfully saved", "response": {"requested_amount": 19.7654, "currency_code": "AED", "created_on":  "2019-02-05T11:10:58+00:00", "id": 4, "updated_on": "2019-02-05T11:10:58+00:00", "open_exchange_price": 3.67328, "final_amount": 72.6039}, "success": true}
  

• curl -H "Content-Type: application/json" -X POST -d '{"requested_amount": 19.7654}' http://127.0.0.1:5000/api/grab_and_save

  {"message": "Params are missing", "response": {}, "success": true}
  

• curl -H "Content-Type: application/json" -X POST -d '{"currency_code": "AED", "requested_amount": -0.34567309}' http://127.0.0.1:5000/api/grab_and_save

  {"message": "Invalid data", "response": {}, "success": true}
  

• curl -X GET http://127.0.0.1:5000/api/last

  {"message": null, "response": {"requested_amount": 19.7654, "currency_code": "AED", "created_on": "2019-02-05T11:10:58+00:00", "id": 4, "updated_on": "2019-02-05T11:10:58+00:00", "open_exchange_price": 3.67328, "final_amount": 72.6039}, "success": true}
  

• curl -X GET "http://127.0.0.1:5000/api/last?no_of_operations=3"

  {"message": null, "response": [{"requested_amount": 19.7654, "currency_code": "AED", "created_on": "2019-02-05T11:10:58+00:00", "id": 4, "updated_on": "2019-02-05T11:10:58+00:00", "open_exchange_price": 3.67328, "final_amount": 72.6039}, {"requested_amount": 19.7654, "currency_code": "AED", "created_on": "2019-02-05T10:18:42+00:00", "id": 3, "updated_on": "2019-02-05T10:18:42+00:00", "open_exchange_price": 3.67316, "final_amount": 72.6014}, {"requested_amount": 19.7654, "currency_code": "AED", "created_on": "2019-02-05T09:21:50+00:00", "id": 2, "updated_on": "2019-02-05T09:21:50+00:00", "open_exchange_price": 3.67316, "final_amount": 72.6014}], "success": true}
  

• curl -X GET "http://127.0.0.1:5000/api/last?currency_code=ALL"

  {"message": null, "response": {"requested_amount": 11.9854, "currency_code": "ALL", "created_on": "2019-02-05T09:21:04+00:00", "id": 1, "updated_on": "2019-02-05T09:21:04+00:00", "open_exchange_price": 109.15, "final_amount": 1308.21}, "success": true}
  

• curl -X GET "http://127.0.0.1:5000/api/last?currency_code=AED&no_of_operations=2"

  {"message": null, "response": [{"requested_amount": 19.7654, "currency_code": "AED", "created_on": "2019-02-05T11:10:58+00:00", "id": 4, "updated_on": "2019-02-05T11:10:58+00:00", "open_exchange_price": 3.67328, "final_amount": 72.6039}, {"requested_amount": 19.7654, "currency_code": "AED", "created_on": "2019-02-05T10:18:42+00:00", "id": 3, "updated_on": "2019-02-05T10:18:42+00:00", "open_exchange_price": 3.67316, "final_amount": 72.6014}], "success": true}
  

• curl -X GET "http://127.0.0.1:5000/api/last?currency_code=AFB"

  {"success": true, "response": {}, "message": "Does Not Exists"}