Dockerfile

# Production Dockerfile for CheckMate (Next.js)
# Multi-stage build optimized for minimal image size and security

# =============================================================================
# Stage 1: Dependencies
# =============================================================================
FROM node:20-alpine AS deps

WORKDIR /app

# Install libc6-compat for Alpine compatibility with native modules
RUN apk add --no-cache libc6-compat

# Copy package files for dependency installation
COPY package.json package-lock.json ./

# Install production dependencies only
RUN npm ci --only=production

# =============================================================================
# Stage 2: Builder
# =============================================================================
FROM node:20-alpine AS builder

WORKDIR /app

# Install libc6-compat for build process
RUN apk add --no-cache libc6-compat

# Copy package files
COPY package.json package-lock.json ./

# Install all dependencies (including devDependencies for build)
RUN npm ci

# Copy source code
COPY . .

# Disable Next.js telemetry during build
ENV NEXT_TELEMETRY_DISABLED=1

# Enable standalone output for Docker builds
ENV DOCKER_BUILD=true

# Build the application with standalone output
RUN npm run build

# =============================================================================
# Stage 3: Runner (Production)
# =============================================================================
FROM node:20-alpine AS runner

WORKDIR /app

# Set production environment
ENV NODE_ENV=production
ENV NEXT_TELEMETRY_DISABLED=1

# Install security updates and create non-root user
RUN apk add --no-cache libc6-compat \
    && addgroup --system --gid 1001 nodejs \
    && adduser --system --uid 1001 nextjs

# Copy public assets
COPY --from=builder /app/public ./public

# Set correct permissions for prerender cache
RUN mkdir .next \
    && chown nextjs:nodejs .next

# Copy standalone build output
# The standalone output includes only necessary node_modules
COPY --from=builder --chown=nextjs:nodejs /app/.next/standalone ./
COPY --from=builder --chown=nextjs:nodejs /app/.next/static ./.next/static

# Switch to non-root user for security
USER nextjs

# Expose the application port
EXPOSE 3000

# Set the port environment variable
ENV PORT=3000
ENV HOSTNAME="0.0.0.0"

# Start the production server
CMD ["node", "server.js"]