This hands-on guide walks you through setting up a production-like environment for a Django web application using Docker containers for the web server (Gunicorn), reverse proxy (Nginx), and database (PostgreSQL).

Prerequisites

Before you begin, ensure you have the following installed and configured:

• Ubuntu 20.04+ (or similar Linux): Provides the environment to install and run Docker. The commands provided are tailored for Debian/Ubuntu based systems.
• Sudo or root privileges: Required to install system-level packages and manage the Docker daemon permissions.
• Docker & Docker CLI installed: The core tools for building and running containers. (See previous "Docker Basics" guide if needed).
• (Optional) Docker Compose installed: While this guide uses basic docker commands, Docker Compose is the standard tool for managing multi-container applications and is highly recommended for production. (We'll stick to basic commands here for clarity, but note where Compose would simplify things).
• Internet access: Necessary to download operating system packages, Python libraries, and Docker images from repositories.

Part 1: Prepare Python Environment with pyenv

We start by setting up a clean and isolated Python environment on your host machine using pyenv. This is good practice for local development and helps ensure you can install the specific Python version and libraries needed before transferring them into the Docker image.

• Install system build dependencies

  • *pyenv builds Python versions from source code. These packages provide the necessary compilers, libraries, and headers required for a successful Python build on Linux.*

  sudo apt-get update
  sudo apt-get install -y \\
    make build-essential libssl-dev zlib1g-dev \\
    libreadline-dev libsqlite3-dev wget curl llvm \\
    libncursesw5-dev xz-utils tk-dev libxml2-dev \\
    libxmlsec1-dev libffi-dev liblzma-dev
  

• Install pyenv

  • This command downloads and runs the official pyenv installer script. It clones the pyenv repository and sets up its basic structure in your home directory. The following commands add pyenv to your shell's PATH and initialize it, allowing you to use the pyenv command.

  curl <https://pyenv.run> | bash
  # Add to your shell init (~/.bashrc or ~/.zshrc):
  export PATH="$HOME/.pyenv/bin:$PATH"
  eval "$(pyenv init --path)"
  eval "$(pyenv init -)"
  eval "$(pyenv virtualenv-init -)"
  # Apply changes:
  source ~/.bashrc
  

  (Note: You might need to close and reopen your terminal or run source ~/.bashrc or source ~/.zshrc for pyenv to be available.)

• Create & activate a Python 3.11.6 virtualenv

  • *pyenv install 3.11.6 downloads and compiles the specified Python version. pyenv virtualenv 3.11.6 py3_11_6 creates a virtual environment named py3_11_6 based on that Python version. pyenv activate py3_11_6 switches your current shell session to use this virtual environment, isolating installed libraries.*

  pyenv install --list       # see available versions
  pyenv install 3.11.6
  pyenv virtualenv 3.11.6 py3_11_6
  pyenv activate py3_11_6
  

• Install Python libraries

  • Installs the required Python packages within the currently active virtual environment. django is the web framework, gunicorn is a production-ready Python WSGI HTTP Server (used later in Docker), psycopg2-binary is the PostgreSQL adapter for Python, and pyyaml is often used for configuration files, though not strictly necessary for this basic example it's a common dependency.

  pip install django gunicorn psycopg2-binary pyyaml
  

• Deactivate when done

  • Exits the virtual environment, returning your shell to the system or global Python environment.

  pyenv deactivate
  

Part 2: Create a Django Project Locally

Now, we'll create a basic Django project within the prepared Python environment.