Building Production-Grade Microservices with Next.js 15, Docker & Kubernetes

// next.config.ts
import type { NextConfig } from "next";

const nextConfig: NextConfig = {
  output: "standalone",
  reactStrictMode: true,
  poweredByHeader: false, // Security hardening
};

export default nextConfig;

# ============================================
# STAGE 1: Dependency Resolver
# ============================================
FROM node:20-alpine AS deps
RUN apk add --no-libc-dev libc6-compat
WORKDIR /app

COPY package.json package-lock.json ./
RUN npm ci

# ============================================
# STAGE 2: Standalone Builder
# ============================================
FROM node:20-alpine AS builder
WORKDIR /app
COPY --from=deps /app/node_modules ./node_modules
COPY . .

# Environment build args for public client routes
ARG NEXT_PUBLIC_SITE_URL
ENV NEXT_PUBLIC_SITE_URL=${NEXT_PUBLIC_SITE_URL}

ENV NEXT_TELEMETRY_DISABLED=1
RUN npm run build

# ============================================
# STAGE 3: Production Runner (Hardened)
# ============================================
FROM node:20-alpine AS runner
WORKDIR /app

ENV NODE_ENV=production
ENV NEXT_TELEMETRY_DISABLED=1
ENV PORT=3000
ENV HOSTNAME="0.0.0.0"

# Create unprivileged system user for container security
RUN addgroup --system --gid 1001 nodejs
RUN adduser --system --uid 1001 nextjs

COPY --from=builder /app/public ./public

# Set ownership permissions for standalone output
COPY --from=builder --chown=nextjs:nodejs /app/.next/standalone ./
COPY --from=builder --chown=nextjs:nodejs /app/.next/static ./.next/static

USER nextjs

EXPOSE 3000

CMD ["node", "server.js"]

# k8s-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nextjs-microservice
  namespace: production
  labels:
    app: nextjs-web
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nextjs-web
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 0
  template:
    metadata:
      labels:
        app: nextjs-web
    spec:
      containers:
        - name: nextjs-app
          image: registry.ajitdev.com/nextjs-web:v1.2.0
          imagePullPolicy: IfNotPresent
          ports:
            - containerPort: 3000
          resources:
            requests:
              memory: "128Mi"
              cpu: "100m"
            limits:
              memory: "512Mi"
              cpu: "500m"
          # Health Probes for Zero-Downtime Rollouts
          livenessProbe:
            httpGet:
              path: /api/health
              port: 3000
            initialDelaySeconds: 15
            periodSeconds: 10
          readinessProbe:
            httpGet:
              path: /
              port: 3000
            initialDelaySeconds: 5
            periodSeconds: 5
          envFrom:
            - configMapRef:
                name: nextjs-config
            - secretRef:
                name: nextjs-secrets

---
apiVersion: v1
kind: Service
metadata:
  name: nextjs-service
  namespace: production
spec:
  type: ClusterIP
  ports:
    - port: 80
      targetPort: 3000
      protocol: TCP
  selector:
    app: nextjs-web

// app/api/health/route.ts
import { NextResponse } from "next/server";

export async function GET() {
  return NextResponse.json(
    {
      status: "healthy",
      timestamp: new Date().toISOString(),
      uptime: process.uptime(),
    },
    { status: 200 }
  );
}