Fix image optimization in standalone builds

Dockerfile

@@ -1,42 +1,53 @@
+FROM node:20-alpine AS base
+
 # Install dependencies only when needed
-FROM node:18-alpine AS deps
+FROM base AS deps
 # Check https://github.com/nodejs/docker-node/tree/b4117f9333da4138b03a546ec926ef50a31506c3#nodealpine to understand why libc6-compat might be needed.
 RUN apk add --no-cache libc6-compat
 WORKDIR /app
 
 # Install dependencies based on the preferred package manager
-COPY package.json package-lock.json* ./
-RUN --mount=type=cache,target=/root/.npm npm_config_platform=linux npm_config_arch=x64 npm_config_libc=glibc npm ci
-RUN npm rebuild --platform=linux --arch=x64 --libc=musl sharp
+COPY package.json package-lock.json ./
+RUN npm ci
+RUN npm install --os=linuxmusl --cpu=x64 sharp
 
 # Rebuild the source code only when needed
-FROM node:18-alpine AS builder
+FROM base AS builder
 WORKDIR /app
 COPY --from=deps /app/node_modules ./node_modules
 COPY . .
 
 RUN --mount=type=cache,target=/app/.next/cache npm run build
 
 # Production image, copy all the files and run next
-FROM node:18-slim AS runner
+FROM base AS runner
 WORKDIR /app
 
 ENV NODE_ENV production
 
 RUN addgroup --system --gid 1001 nodejs
 RUN adduser --system --uid 1001 nextjs
+RUN npm install --os=linuxmusl --cpu=x64 sharp
 
 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
 
 USER nextjs
 
-EXPOSE 80
+EXPOSE 3000
 
-ENV PORT 80
+ENV PORT 3000
+# set hostname to localhost
+ENV HOSTNAME "0.0.0.0"
 
-CMD ["node", "server.js"]
+# 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"]

next.config.js

@@ -6,6 +6,11 @@ const nextConfig = {
             "gray-matter",
             "mdast-util-find-and-replace",
         ],
+        outputFileTracingIncludes: {
+            // This is a workaround to force nft to trace Sharp binaries,
+            // which will cause them to be included in the Docker image.
+            "/": ["./node_modules/@img/**"],
+        },
     },
     output: "standalone",
     images: {