Dockerfile

# Multi-stage Dockerfile for Next.js (App Router) on Azure-friendly Node 20

# 1) Builder: install deps and build (needs devDependencies)
FROM node:20-alpine AS builder
ENV NEXT_TELEMETRY_DISABLED=1
WORKDIR /app

# Recommended for some native deps on Alpine
RUN apk add --no-cache libc6-compat

# Install dependencies first (better layer caching)
COPY package.json package-lock.json* pnpm-lock.yaml* yarn.lock* ./
RUN \
  if [ -f package-lock.json ]; then npm ci; \
  elif [ -f yarn.lock ]; then corepack enable && yarn install --frozen-lockfile; \
  elif [ -f pnpm-lock.yaml ]; then corepack enable && pnpm install --frozen-lockfile; \
  else npm install; fi

# Copy source and build
COPY . .
RUN npm run build

# 2) Runner: use standalone output for minimal image
FROM node:20-alpine AS runner
ENV NODE_ENV=production
ENV NEXT_TELEMETRY_DISABLED=1
# Next standalone server reads HOSTNAME/PORT
ENV HOSTNAME=0.0.0.0
ENV PORT=3000
WORKDIR /app

# Create non-root user
RUN addgroup -S nextjs && adduser -S nextjs -G nextjs

# Copy standalone output produced by `next build`
COPY --from=builder /app/.next/standalone ./
COPY --from=builder /app/.next/static ./.next/static
COPY --from=builder /app/public ./public

# Do NOT bake env files; configure env in Azure App Settings
# COPY .env ./.env

USER nextjs
EXPOSE 3000

# Simple HTTP healthcheck (adjust path if you have a dedicated health endpoint)
HEALTHCHECK --interval=30s --timeout=5s --start-period=30s --retries=3 \
  CMD node -e "require('http').get({host:'127.0.0.1',port:process.env.PORT||3000,path:'/'},r=>process.exit(r.statusCode<500?0:1)).on('error',()=>process.exit(1))"

# The standalone output includes server.js at the root
CMD ["node", "server.js"]