Learn DOCKER with Real Code Examples

# Multi-stage Dockerfile for Node.js application
FROM node:18-alpine AS builder

# Set working directory
WORKDIR /app

# Copy package files
COPY package*.json ./

# Install dependencies
RUN npm ci --only=production

# Copy source code
COPY . .

# Build the application
RUN npm run build

# Production stage
FROM node:18-alpine AS production

# Create non-root user
RUN addgroup -g 1001 -S nodejs && \
    adduser -S nextjs -u 1001

# Set working directory
WORKDIR /app

# Copy built application from builder stage
COPY --from=builder --chown=nextjs:nodejs /app/dist ./dist
COPY --from=builder --chown=nextjs:nodejs /app/node_modules ./node_modules
COPY --from=builder --chown=nextjs:nodejs /app/package.json ./package.json

# Health check
HEALTHCHECK --interval=30s --timeout=10s --start-period=60s --retries=3 \
    CMD curl -f http://localhost:3000/health || exit 1

# Switch to non-root user
USER nextjs

# Expose port
EXPOSE 3000

# Set environment variables
ENV NODE_ENV=production
ENV PORT=3000

# Start the application
CMD ["npm", "start"]

Shows best practices for multi-stage builds, security considerations, and optimized Node.js container deployment.