Deploy Django on Railway with this Dockerfile

# Create project directory
mkdir -p ~/dev/saas-foundations
cd ~/dev/saas-foundations

# macos/linux: Create and activate a virtual environment
python3 -m venv venv
source venv/bin/activate

# windows: Create and activate a virtual environment
c:\Python312\python.exe -m venv venv
.\venv\Scripts\activate

# Create requirements.txt
echo "Django>=5.0,<5.1" >> requirements.txt
echo "gunicorn" >> requirements.txt

# install requirements
pip install pip --upgrade
pip install -r requirements.txt

# Start the django project
mkdir -p src
cd src
django-admin startproject cfehome .

ALLOWED_HOSTS = [
    # ...
    ".railway.app",
    # ...
]

cd ~/dev/saas-foundations
echo "" >> Dockerfile

# Set the python version as a build-time argument
# with Python 3.12 as the default
ARG PYTHON_VERSION=3.12-slim-bullseye
FROM python:${PYTHON_VERSION}

# Create a virtual environment
RUN python -m venv /opt/venv

# Set the virtual environment as the current location
ENV PATH=/opt/venv/bin:$PATH

# Upgrade pip
RUN pip install --upgrade pip

# Set Python-related environment variables
ENV PYTHONDONTWRITEBYTECODE 1
ENV PYTHONUNBUFFERED 1

# Install os dependencies for our mini vm
RUN apt-get update && apt-get install -y \
    # for postgres
    libpq-dev \
    # for Pillow
    libjpeg-dev \
    # for CairoSVG
    libcairo2 \
    # other
    gcc \
    && rm -rf /var/lib/apt/lists/*

# Create the mini vm's code directory
RUN mkdir -p /code

# Set the working directory to that same code directory
WORKDIR /code

# Copy the requirements file into the container
COPY requirements.txt /tmp/requirements.txt

# copy the project code into the container's working directory
COPY ./src /code

# Install the Python project requirements
RUN pip install -r /tmp/requirements.txt

# database isn't available during build
# run any other commands that do not need the database
# such as:
# RUN python manage.py collectstatic --noinput

# set the Django default project name
ARG PROJ_NAME="cfehome"

# create a bash script to run the Django project
# this script will execute at runtime when
# the container starts and the database is available
RUN printf "#!/bin/bash\n" > ./paracord_runner.sh && \
    printf "RUN_PORT=\"\${PORT:-8000}\"\n\n" >> ./paracord_runner.sh && \
    printf "python manage.py migrate --no-input\n" >> ./paracord_runner.sh && \
    printf "gunicorn ${PROJ_NAME}.wsgi:application --bind \"[::]:\$RUN_PORT\"\n" >> ./paracord_runner.sh

# make the bash script executable
RUN chmod +x paracord_runner.sh

# Clean up apt cache to reduce image size
RUN apt-get remove --purge -y \
    && apt-get autoremove -y \
    && apt-get clean \
    && rm -rf /var/lib/apt/lists/*

# Run the Django project via the runtime script
# when the container starts
CMD ./paracord_runner.sh

cd ~/dev/saas-foundations
echo "" >> railway.json

{
    "build": {
        "builder": "DOCKERFILE",
        "dockerfilePath": "./Dockerfile",
        "watchPatterns": [
            "requirements.txt",
            "src/**",
            "railway.json",
            "Dockerfile"
        ]
    }
}