Gunicorn hot reload with Docker Compose

12 Nov 2021

Let’s suppose you want to use the same Dockerfile to run in production and in development mode, and want to use Docker Compose to set up the development environment.

The trick here is to pass an argument to Docker during the build called options, and inside this argument is possible to pass --reload responsible to reload the code on each change.

ARG options
ENV OPTIONS $options

CMD exec gunicorn $OPTIONS --bind :$PORT --workers 1 --threads 8 --timeout 0 main:app

And on docker-compose.yaml will be need two things:

• Pass --reload as a Docker argument to the container, using args.
• Mount the local directory inside the container, using the volumes.

version: "3"
services:
  app:
    build:
      context: .
      args:
        options: --reload
    volumes:
      - ./:/app

Full example github.com/skhaz/docker-compose-gunicorn-hot-reload