Python Web API Coding Demonstration

This project is meant to demonstrate my ability to create a web-based API server using pre-defined functional requirements. The initial project scope took a weekend to create, and revisions will remain ongoing as skills develop and time/resources allow.

Technical Stack

This API service implements a few key libraries for demonstration of various related skill sets:

• Python 3.8
• Flask - A lightweight WSGI web application framework for Python
• Black - An uncompromising Python code formatter
• Pytest - Small, scalable testing for Python
• Poetry - Python packaging made easy
• OAS v3.0 - OpenAPI Specification (Swagger), an industry standard for describing modern APIs
• Github Actions - Version control and test-build-deploy pipeline automation
• Docker - Containerization for faster, consistent and more reliable development

Installation

This demo app requires Python 3.8 to run. You can run this application in one of two ways: building code from source, or building with a Docker container.

Currently, the Dockerfile is designed to build a production-ready Docker image of minimal image file size. Because of this, all test- and documentation-related code will be ignored when building from the Dockerfile.

If you want to run a live app demonstration without a need to edit code, build with Docker. If you wish to develop code and edit tests/documentation, you will need to build from source.

Build From Source

If needed, create and activate a new Python virtual environment (Pyenv example provided here)

# Create a new virtualenv, if needed
$ pyenv install 3.8.0
$ pyenv virtualenv 3.8.0 api-demo
$ pyenv activate api-demo

Then install and configure normally.

(api-demo)$ pip install --upgrade pip && pip install -r requirements_dev.txt
(api-demo)$ export FLASK_APP=src/app.py && export DEBUG=True && export FLASK_ENV=development
(api-demo)$ flask run

To verify a successful build from source, navigate to: http://localhost:5000/sanity

Build With Docker

Building with Docker is, of course, simpler.

$ docker build -t api-demo .
$ docker run -p 5000:5000 api-demo

To verify a successful build with Docker, navigate to: http://0.0.0.0:5000/sanity

Developer Notes, Coding Challenge, Implementation Details

The coding challenge, along with implementation details and assumptions, and a high level explanation of algorithm and data structure choices are available in this separate requirements document.

Code Style & Best Practices

Black is a Python code style tool based on the PEP8 code style standard and best linting practices. The rationale of this tool is to take out as much of the PEP8 "guess work" as possible, and also to normalize Python code styling for teams with numerous engineers. Black allows engineers to spend less time nitpicking about coding style opinions, and spend more time writing new features, tests, etc.

OpenAPI Specification

The OpenAPI Specification has become a language-agnostic, de facto standard for building, documenting and sharing API structure. The API structure for this project is documented in a separate swagger yml file.

Version Control & CI/CD

This repo leverages Github Actions for CI/CD demonstration purposes. Currently, the Github Actions CI/CD workflow will:

• Install required libraries onto a Python image
• Perform an initial code formatting check with Black
• If formatting checks pass, run test suite with Pytest

Package Management

Although it isn't needed to run a live demo of this application, I use the Poetry tool for Python package management. It is a robust tool to manage project dependencies, especially dependencies that vary based on development/production code environments. Poetry uses the concept of a "lock" file, similar to a package-lock.json or yarn.lock file.

Testing & Coverage

Run the test suite locally with Pytest.

(api-demo)$ pytest

Test coverage reports are available via Codecov.io.

Todos

• Write additional API tests
• Improve Packing Algorithm
• Implement distributed systems deployment (AWS/GCP/Azure)

License

GNU v3.0