Dockerfile

# Use the official Node.js 18 slim image as a base
FROM node:18-slim AS base

# Install dependencies only when needed
FROM base AS deps
WORKDIR /app

# Copy the lockfiles and package.json to install dependencies
COPY package.json yarn.lock* package-lock.json* pnpm-lock.yaml* ./
RUN \
  if [ -f yarn.lock ]; then yarn --frozen-lockfile; \
  elif [ -f package-lock.json ]; then npm ci; \
  elif [ -f pnpm-lock.yaml ]; then corepack enable pnpm && pnpm i --frozen-lockfile; \
  else echo "Lockfile not found." && exit 1; \
  fi

# Rebuild the source code only when needed
FROM base AS builder
WORKDIR /app

# Copy the installed node_modules and the rest of the app's source code
COPY --from=deps /app/node_modules ./node_modules
COPY . .

# Next.js collects completely anonymous telemetry data about general usage.
# Learn more here: https://nextjs.org/telemetry
# Uncomment the following line in case you want to disable telemetry during the build.
ENV NEXT_TELEMETRY_DISABLED 1

RUN \
  if [ -f yarn.lock ]; then yarn run build; \
  elif [ -f package-lock.json ]; then npm run build; \
  elif [ -f pnpm-lock.yaml ]; then corepack enable pnpm && pnpm run build; \
  else echo "Lockfile not found." && exit 1; \
  fi

# Production image, copy all the files and run next
FROM base AS runner
WORKDIR /app

ENV NODE_ENV production
# Uncomment the following line in case you want to disable telemetry during runtime.
ENV NEXT_TELEMETRY_DISABLED 1

# Add a system group and user for running the app
RUN addgroup --system --gid 1001 nodejs
RUN adduser --system --uid 1001 nextjs

# Copy the public folder and the built .next folder
COPY --from=builder /app/public ./public

# Set the correct permission for prerender cache
RUN mkdir .next
RUN chown nextjs:nodejs .next

# Automatically leverage output traces to reduce image size
# https://nextjs.org/docs/advanced-features/output-file-tracing
COPY --from=builder --chown=nextjs:nodejs /app/.next/standalone ./
COPY --from=builder --chown=nextjs:nodejs /app/.next/static ./.next/static

# Switch to the new user
USER nextjs

# Expose the port that the app runs on
EXPOSE 3000

# Set the hostname
ENV HOSTNAME "0.0.0.0"

# server.js is created by next build from the standalone output
# https://nextjs.org/docs/pages/api-reference/next-config-js/output
CMD node server.js