Python UDP server using asyncio

This small project comprises a simple Python UDP server plus Dockerfile, as well as a (hopefully) useful Makefile and unittests.

The server makes use of the asyncio and uvloop libraries to allow for fast, asynchronous request handling.

Check out this blog post if you're interested in more performance details.

Prerequisites

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes.

The code is run and tested with Python 3.7.7 on macOS 10.14.6 and Python 3.8.5 on Ubuntu 18.04.5.

Environment

Clone the repo to your local machine.

Create a virtual environment for Python 3 with:

python3 -m pip install virtualenv
python3 -m virtualenv -p python3 env

Activate the virtual environment with:

source env/bin/activate

Install the required Python packages with:

pip3 install -r requirements.txt

Run the app without Docker

Quickstart (see below for flags, or use -h):

python3 app.py

Stop with Ctrl+C.

Run the app with Docker

Make sure you have Docker installed locally:

docker -v

Quickstart:

make build && make run

Alternatively, build the image locally with:

docker build --tag emoji-app:latest .

Or:

make build

Then, run the container locally with:

docker run --rm --name emoji-app -p 3001:3001/udp emoji-app:latest

Or:

make run

Optionally, the following flags can be used: --n, --r, --s and --h/-h:

• --n Multiply number of emojis by n (int, default: 1)
• --r Disable translation from keyword to emoji (bool, default: False)
• --s Separator between each emoji (str, default: "")
• --h/-h See usage information

For example:

docker run --rm --name emoji-app -p 3001:3001/udp emoji-app:latest --n 2 --r True --s "+"

In another shell session, you can now trigger the endpoint (0.0.0.0:3001), for example using nc:

nc -u 0.0.0.0 3001

Send a message and hit enter:

2 :ok:

Development and testing

Using the Makefile you can run make <cmd> where <cmd> is one of:

• sort-imports to ensure Python imports are in the correct PEP format/order
• format to format Python files using black
• type-check to run static type checking using mypy
• test to run unittests using pytest
• all to run all steps (or just type make)

Authors

• Manuel Zander

Acknowledgments

Many thanks to julvo for his review and great suggestions during development of this software 😊