Docker setup for ToDo app

.dockerignore

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+.github
+.venv
+__pycache__
+.git
+.gitignore
+Dockerfile
+docker-compose.yml
+INSTRUCTION.md
+README.md
+.dockerignore
+.pre-commit-config.yaml
+.travis.yml

Dockerfile

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+### Builder stage
+ARG PYTHON_VERSION=3.8
+
+FROM python:${PYTHON_VERSION}-slim AS builder
+
+WORKDIR /app
+
+COPY requirements.txt .
+
+# Install system build dependencies and Python build 
+RUN apt-get update \
+     && apt-get install -y --no-install-recommends \
+         build-essential \
+         gcc \
+         python3-dev \
+         libbz2-dev \
+         libssl-dev \
+         libffi-dev \
+     && rm -rf /var/lib/apt/lists/* \
+     && pip install --upgrade pip wheel \
+     && pip install --no-cache-dir \
+         --prefix=/install \
+         -r requirements.txt
+
+### Runtime stage
+FROM python:${PYTHON_VERSION}-slim
+
+ENV PYTHONUNBUFFERED=1 
+
+WORKDIR /app
+
+# Create non-root user
+RUN useradd --create-home --uid 1001 appuser
+
+# Copy installed packages
+COPY --from=builder /install /usr/local
+
+# Copy application source
+COPY . .
+
+# Set ownership
+RUN chown -R appuser:appuser /app
+
+# Switch to non-root user
+USER appuser
+
+RUN python manage.py migrate
+
+# Application port
+EXPOSE 8080
+
+# Start app
+CMD ["python", "manage.py", "runserver", "0.0.0.0:8080"] 

INSTRUCTION.md

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+Docker Hub image
+---------------
+
+This repository has a prebuilt Docker image available on Docker Hub:
+
+https://hub.docker.com/r/verteiger/todoapp
+
+Quick start — pull and run
+--------------------------
+
+1. Pull the image from Docker Hub:
+
+   docker pull verteiger/todoapp:1.0.0
+
+2. Run the container, mapping the container port 8080 to a host port (example uses host port 8000):
+
+   docker run --rm -p 8000:8080 todoapp:1.0.0
+
+Build the image locally
+-----------------------
+
+If you prefer to build the image from source locally:
+
+1. Build the image (run from the repository root):
+
+   docker build -t todoapp:1.0.0 .
+
+2. Run the locally-built image:
+
+   docker run --rm -p 8000:8080 todoapp:1.0.0
+------------------
+
+To publish your local build to Docker Hub (you must own the `verteiger/todoapp` repo or change the tag to your own):
+
+1. Log in to Docker Hub:
+
+	docker login
+
+2. Tag the image (if needed):
+
+   docker tag todoapp:1.0.0 verteiger/todoapp:1.0.0
+
+3. Push:
+
+   docker push verteiger/todoapp:1.0.0
+
+Notes about the container
+-------------------------
+
+- The container runs the Django development server on port `8080` inside the container (see `Dockerfile`).
+- We recommend mapping it to a non-conflicting host port, e.g. `8000` as shown above.
+- The container runs migrations at start (`python manage.py migrate`) so the first run may take longer.
+
+Access the application in a browser
+----------------------------------
+
+After running the container with `-p 8000:8080`, open your browser and go to:
+
+http://localhost:8000/
+
+If you mapped to a different host port, replace `8000` with that port.
+
+Optional: Docker Compose
+------------------------
+
+Create a `docker-compose.yml` file with a service like:
+
+```yaml
+version: '3.8'
+services:
+  todoapp:
+    image: todoapp:1.0.0
+
+Then run:
+
+```bash
+docker-compose up -d
+```
+
+
+Troubleshooting
+---------------
+
+- If the site is unreachable, check Docker logs:
+
+  docker logs <container-id>
+
+- Ensure no other service is already listening on the chosen host port.