docker-containerization

Docker Containerization

Build production-ready Docker images with multi-stage builds, non-root users, health checks, and docker-compose configurations for local development.

When to Use

• Containerizing a Python (FastAPI/Django) or Node.js (React/Next.js) application
• Creating or optimizing a Dockerfile
• Setting up docker-compose for local development
• Adding health checks, security hardening, or image size optimization
• Configuring multi-service development environments (API + DB + Redis + MinIO)

Available Operations

1. Create multi-stage Dockerfiles for Python applications
2. Create multi-stage Dockerfiles for React/Node.js applications
3. Configure docker-compose for development
4. Add security hardening (non-root user, minimal base image)
5. Add health checks for container orchestration
6. Create .dockerignore for build optimization

Multi-Step Workflow

Step 1: Create .dockerignore

Always start with .dockerignore to prevent unnecessary files from entering the build context.

.git
node_modules
__pycache__
*.pyc
.env
.venv
dist
build
coverage
.pytest_cache

Step 2: Create the Dockerfile (Python)

Use multi-stage build for minimal image size.

# === Build stage ===
FROM python:3.11-slim AS builder
WORKDIR /app
RUN apt-get update && apt-get install -y --no-install-recommends gcc && rm -rf /var/lib/apt/lists/*
COPY requirements.txt .
RUN pip install --no-cache-dir --prefix=/install -r requirements.txt

# === Runtime stage ===
FROM python:3.11-slim
WORKDIR /app
RUN groupadd -r appuser && useradd -r -g appuser appuser
COPY --from=builder /install /usr/local
COPY src/ ./src/
USER appuser
EXPOSE 8000
HEALTHCHECK --interval=30s --timeout=5s CMD curl -f http://localhost:8000/health || exit 1
CMD ["uvicorn", "src.main:app", "--host", "0.0.0.0", "--port", "8000"]

Step 3: Create the Dockerfile (React)

FROM node:20-slim AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci
COPY . .
RUN npm run build

FROM nginx:alpine
COPY --from=builder /app/dist /usr/share/nginx/html
COPY nginx.conf /etc/nginx/conf.d/default.conf
EXPOSE 80