BookEx

This repo aims to build a microservice app that explores books,

• Python: version 3.10
• Flask : a python web framework that we use to build backend api
• SQLAlchemy: For the ORM
• Alembic : for the database migration
• Postgresql : a relational database that will store our data,
• Docker : to containerized our application,
• Docker Compose: For development
• Nginx as server and reserve proxy

Steps to launch the app

Run the following commands :

Create the workspace repository and clone the project

mkdir /home/projects/BookEx && cd /home/projects/BookEx
git clone https://github.com/carmel-wenga/python-flask-crud-api-for-book-library

Before being able to run the app, you need to create the virtualenv

How to install/create the virtualenv on windows and linux ? Add those steps

mkdir lib/env

1. Build and run the app

docker-compose up -d --build 

2. Initialize the database and run the migrations

Script initdb.sh contains the commands below to initialize the database and run the migrations

docker-compose exec backend flask db init
docker-compose exec backend flask db migrate -m "initial migrations"
docker-compose exec backend flask db upgrade

3. Use the following command to connect to the postgres image and inspect the contains of the database

docker-compose exec database psql --username=pguser --dbname=bookexdb

Note that the username pguser and the database name bookexdb are defined in the .env file that should contain secrets information about the application. It should not be tracker by git.

App Structure

This Backend App exposes 5 endpoints:

1. Create Book: endpoint is used to create a book

curl --location --request POST 'localhost:5000/api/v1/books/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "isbn": "9780439358071",
    "title": "Harry Potter and the Order of the Phoenix",
    "authors": "J.K. Rowling, Mary GrandPré (Illustrator)",
    "description": "There is a door at the end of a silent corridor. And it’s haunting Harry Pottter’s dreams. Why else would he be waking in the middle of the night, screaming in terror?Harry has a lot on his mind for this, his fifth year at Hogwarts: a Defense Against the Dark Arts teacher with a personality like poisoned honey; a big surprise on the Gryffindor Quidditch team; and the looming terror of the Ordinary Wizarding Level exams. But all these things pale next to the growing threat of He-Who-Must-Not-Be-Named - a threat that neither the magical government nor the authorities at Hogwarts can stop.As the grasp of darkness tightens, Harry must discover the true depth and strength of his friends, the importance of boundless loyalty, and the shocking price of unbearable sacrifice.His fate depends on them all.",
    "language": "English",
    "genres": "Fantasy, Young Adult, Fiction, Magic, Childrens, Adventure, Audiobook, Middle Grade, Classics, Science Fiction Fantasy",
    "publisher": "Scholastic Inc.",
    "publish_date": "2004-09-28",
    "price": 7.38,
    "pages": 870
  }'

2. Read Book: Add new book in the database

curl --location --request GET 'localhost:5000/api/v1/books/9780439358071'

3. Update Book

curl --location --request PUT 'localhost:5000/api/v1/books/9780439358071' \
--header 'Content-Type: application/json' \
--data-raw '{
    "authors": "J.K. Rowling, Mary GrandPré",
    "language": "English",
    "pages": 950,
    "price": 15.38
}'

4. Delete Book

curl --location --request DELETE 'localhost:5000/api/v1/books/9780439358071'

5. Get all book

curl --location --request GET 'localhost:5000/api/v1/books/'

Go to http://localhost:5000/api/docs for more details on the description of the api.

Project Structure

BookEx
├── app
│   ├── api
│   │   └── v1
│   │       ├── books
│   │       │   ├── __init__.py
│   │       │   └── views.py
│   │       └── __init__.py
│   ├── domain
│   │   └── books
│   │       ├── models.py
│   │       └── utils.py
│   ├── __init__.py
│   ├── main
│   │   ├── __init__.py
│   │   └── views.py
│   └── static
│       └── yml
│           └── swagger.yml
├── books.csv
├── config.py
├── docker-compose.yml
├── Dockerfile
├── .dockerignore
├── .env
├── .gitignore
├── manage.py
├── README.md
├── requirements.txt
├── settings.py
└── utils.py

---

1. Entrypoint of the app

The entry point of the application is the app/__init__.py file. The code below creates the flask app, configure it, creates the sqlalchemy db and link both the app and the db together

# create flask app
app = Flask(__name__)

# Allow CORS for all routes
CORS(app)

# import flask configurations
app.config.from_object(Config)

# create the database
db = SQLAlchemy(app)

Migrate(app, db)

• The api package contains only one version of the api server. The first version v1. The api/v1/books/views.py contains all the endpoints for CRUD operations on books

• The domain/books/models.py files defines the Books models and domain/books/utils.py defines useful functions on books

• static/yml/swagger.yml is the openapi documentation of the api