docker-1-basic-dockerfile-patterns

# 1. Basic Dockerfile Patterns

## 1. Basic Dockerfile Patterns


**Simple Application Dockerfile:**
```dockerfile
# Base image with specific version
FROM python:3.12-slim

# Set working directory
WORKDIR /app

# Set environment variables
ENV PYTHONDONTWRITEBYTECODE=1 \
    PYTHONUNBUFFERED=1 \
    PIP_NO_CACHE_DIR=1

# Install system dependencies
RUN apt-get update && apt-get install -y --no-install-recommends \
    gcc \
    libpq-dev \
    && rm -rf /var/lib/apt/lists/*

# Copy dependency files first (better caching)
COPY requirements.txt .

# Install Python dependencies
RUN pip install --no-cache-dir -r requirements.txt

# Copy application code
COPY . .

# Create non-root user
RUN useradd --create-home appuser && chown -R appuser:appuser /app
USER appuser

# Expose port
EXPOSE 8000

# Health check
HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
    CMD curl -f http://localhost:8000/health || exit 1

# Default command
CMD ["python", "main.py"]
```

**Node.js Application Dockerfile:**
```dockerfile
FROM node:20-alpine

WORKDIR /app

# Copy package files
COPY package*.json ./

# Install dependencies
RUN npm ci --only=production

# Copy application
COPY . .

# Non-root user (alpine already has 'node' user)
USER node

EXPOSE 3000

HEALTHCHECK --interval=30s --timeout=3s \
    CMD wget --no-verbose --tries=1 --spider http://localhost:3000/health || exit 1

CMD ["node", "server.js"]
```