Deploy Spring Cloud Microservices to Production on Kubernetes – Revised Edition

1. Goal of This Episode

The previous episode used Docker Compose for one‑click local deployment; production requires stronger capabilities: automatic scaling, rolling updates, self‑healing, and load balancing.

2. Project Structure

# spring-cloud-teaching-ep11/
├── k8s/
│   ├── namespace.yaml          # Namespace definition
│   ├── configmap.yaml          # ConfigMap definition
│   ├── secrets.yaml             # Secrets definition
│   ├── nacos/
│   │   ├── deployment.yaml
│   │   └── service.yaml
│   ├── order-service/
│   │   ├── deployment.yaml
│   │   ├── service.yaml
│   │   └── hpa.yaml
│   ├── stock-service/
│   │   ├── deployment.yaml
│   │   ├── service.yaml
│   │   └── hpa.yaml
│   ├── point-service/
│   │   ├── deployment.yaml
│   │   ├── service.yaml
│   │   └── hpa.yaml
│   ├── ingress.yaml
│   └── kustomization.yaml
├── scripts/
│   ├── deploy.sh               # Deployment script
│   ├── undeploy.sh             # Uninstall script
│   └── status.sh               # Status check script
├── docker/
│   ├── Dockerfile
│   └── push.sh
└── README.md

3. Detailed K8s Configuration Files

3.1 Namespace

apiVersion: v1
kind: Namespace
metadata:
  name: teaching-cloud

3.2 ConfigMap

apiVersion: v1
kind: ConfigMap
metadata:
  name: teaching-config
  namespace: teaching-cloud
data:
  NACOS_HOST: "nacos.teaching-cloud.svc.cluster.local"
  DB_HOST: "mysql.teaching-cloud.svc.cluster.local"
  SEATA_HOST: "seata-server.teaching-cloud.svc.cluster.local"
  application.yml: |
    spring:
      cloud:
        nacos:
          discovery:
            server-addr: nacos.teaching-cloud.svc.cluster.local:8848
      datasource:
        url: jdbc:mysql://mysql.teaching-cloud.svc.cluster.local:3306/order_db
        username: root
        password: ${DB_PASSWORD}

3.3 Secrets

apiVersion: v1
kind: Secret
metadata:
  name: teaching-secrets
  namespace: teaching-cloud
type: Opaque
stringData:
  DB_PASSWORD: "root123"
  MYSQL_ROOT_PASSWORD: "root123"

3.4 Nacos Deployment

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nacos
  namespace: teaching-cloud
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nacos
  template:
    metadata:
      labels:
        app: nacos
    spec:
      containers:
      - name: nacos
        image: nacos/nacos-server:v2.3.2
        ports:
        - containerPort: 8848
          name: http
        - containerPort: 9848
          name: grpc
        env:
        - name: MODE
          value: "standalone"
        resources:
          requests:
            memory: "512Mi"
            cpu: "250m"
          limits:
            memory: "1Gi"
            cpu: "500m"
        livenessProbe:
          httpGet:
            path: /nacos/actuator/health
            port: 8848
          initialDelaySeconds: 60
          periodSeconds: 10
        readinessProbe:
          httpGet:
            path: /nacos/actuator/health
            port: 8848
          initialDelaySeconds: 30
          periodSeconds: 5

3.5 Nacos Service

apiVersion: v1
kind: Service
metadata:
  name: nacos
  namespace: teaching-cloud
spec:
  selector:
    app: nacos
  ports:
  - name: http
    port: 8848
    targetPort: 8848
  - name: grpc
    port: 9848
    targetPort: 9848
  type: ClusterIP

3.6 Order‑Service Deployment

apiVersion: apps/v1
kind: Deployment
metadata:
  name: order-service
  namespace: teaching-cloud
spec:
  replicas: 2
  selector:
    matchLabels:
      app: order-service
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 0
  template:
    metadata:
      labels:
        app: order-service
    spec:
      containers:
      - name: order-service
        image: teaching/order-service:latest
        imagePullPolicy: Always
        ports:
        - containerPort: 8081
          name: http
        env:
        - name: SPRING_PROFILES_ACTIVE
          value: "k8s"
        - name: DB_PASSWORD
          valueFrom:
            secretKeyRef:
              name: teaching-secrets
              key: DB_PASSWORD
        resources:
          requests:
            memory: "256Mi"
            cpu: "200m"
          limits:
            memory: "512Mi"
            cpu: "500m"
        livenessProbe:
          httpGet:
            path: /actuator/health/liveness
            port: 8081
          initialDelaySeconds: 90
          periodSeconds: 10
        readinessProbe:
          httpGet:
            path: /actuator/health/readiness
            port: 8081
          initialDelaySeconds: 60
          periodSeconds: 5

3.7 Order‑Service Service

apiVersion: v1
kind: Service
metadata:
  name: order-service
  namespace: teaching-cloud
spec:
  selector:
    app: order-service
  ports:
  - port: 8081
    targetPort: 8081
    name: http
  type: ClusterIP

3.8 Order‑Service HPA

apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: order-service-hpa
  namespace: teaching-cloud
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: order-service
  minReplicas: 2
  maxReplicas: 10
  metrics:
  - type: Resource
    resource:
      name: cpu
      target:
        type: Utilization
        averageUtilization: 70
  - type: Resource
    resource:
      name: memory
      target:
        type: Utilization
        averageUtilization: 80

3.9 Stock‑Service Deployment (similar structure to Order‑Service)

# (omitted for brevity – same pattern with image teaching/stock-service:latest and port 8082)

3.10 Stock‑Service HPA

# (omitted for brevity – same metrics as order‑service)

3.11 Point‑Service Deployment (similar structure, port 8083)

# (omitted for brevity – same pattern with image teaching/point-service:latest)

3.12 Point‑Service HPA

# (omitted for brevity – same metrics as order‑service)

3.13 Ingress

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: teaching-ingress
  namespace: teaching-cloud
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: "/"
    nginx.ingress.kubernetes.io/ssl-redirect: "false"
spec:
  ingressClassName: nginx
  rules:
  - host: api.teaching.com
    http:
      paths:
      - path: /api/order
        pathType: Prefix
        backend:
          service:
            name: order-service
            port:
              number: 8081
      - path: /api/stock
        pathType: Prefix
        backend:
          service:
            name: stock-service
            port:
              number: 8082
      - path: /api/point
        pathType: Prefix
        backend:
          service:
            name: point-service
            port:
              number: 8083

3.14 Kustomize Configuration

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: teaching-cloud
resources:
- namespace.yaml
- configmap.yaml
- secrets.yaml
- nacos/deployment.yaml
- nacos/service.yaml
- order-service/deployment.yaml
- order-service/service.yaml
- order-service/hpa.yaml
- stock-service/deployment.yaml
- stock-service/service.yaml
- stock-service/hpa.yaml
- point-service/deployment.yaml
- point-service/service.yaml
- point-service/hpa.yaml
- ingress.yaml
images:
- name: teaching/order-service
  newTag: latest
- name: teaching/stock-service
  newTag: latest
- name: teaching/point-service
  newTag: latest

4. Docker Image Build

# Dockerfile
FROM openjdk:17-jdk-slim
WORKDIR /app
RUN apt-get update && apt-get install -y curl && rm -rf /var/lib/apt/lists/*
RUN groupadd -r teaching && useradd -r -g teaching teaching
COPY target/*.jar app.jar
USER teaching
EXPOSE 8081
ENV JAVA_OPTS="-Xms256m -Xmx512m -XX:+UseG1GC"
ENTRYPOINT ["sh", "-c", "java $JAVA_OPTS -jar app.jar"]

# push.sh (build and push images)
#!/bin/bash
REGISTRY=${REGISTRY:-docker.io/teaching}
TAG=${TAG:-latest}
services=("order-service" "stock-service" "point-service")
for service in "${services[@]}"; do
  echo "Building $service..."
  cd ../services/$service
  mvn clean package -DskipTests
  docker build -t ${REGISTRY}/${service}:${TAG} -f ../../docker/Dockerfile .
  docker push ${REGISTRY}/${service}:${TAG}
  cd -
done
echo "✅ All images built and pushed"

5. Deployment Scripts

# deploy.sh (deployment script)
#!/bin/bash
set -e

echo "🚀 Deploying to Kubernetes..."

# Ensure namespace exists
if ! kubectl get namespace teaching-cloud >/dev/null 2>&1; then
  echo "Creating namespace..."
  kubectl create namespace teaching-cloud
fi

# Deploy ConfigMap and Secrets
echo "Deploying ConfigMap and Secrets..."
kubectl apply -f ../k8s/configmap.yaml
kubectl apply -f ../k8s/secrets.yaml

# Deploy Nacos
echo "Deploying Nacos..."
kubectl apply -f ../k8s/nacos/deployment.yaml
kubectl apply -f ../k8s/nacos/service.yaml

# Wait for Nacos to become ready
echo "Waiting for Nacos to become ready..."
kubectl wait --for=condition=available --timeout=300s deployment/nacos -n teaching-cloud

# Deploy business services
echo "Deploying business services..."
kubectl apply -f ../k8s/order-service/deployment.yaml
kubectl apply -f ../k8s/order-service/service.yaml
kubectl apply -f ../k8s/order-service/hpa.yaml

kubectl apply -f ../k8s/stock-service/deployment.yaml
kubectl apply -f ../k8s/stock-service/service.yaml
kubectl apply -f ../k8s/stock-service/hpa.yaml

kubectl apply -f ../k8s/point-service/deployment.yaml
kubectl apply -f ../k8s/point-service/service.yaml
kubectl apply -f ../k8s/point-service/hpa.yaml

# Deploy Ingress
echo "Deploying Ingress..."
kubectl apply -f ../k8s/ingress.yaml

echo "✅ Deployment completed!"

echo "Check status:"
echo "  kubectl get pods -n teaching-cloud"
echo "  kubectl get svc -n teaching-cloud"
echo "  kubectl get ingress -n teaching-cloud"

# undeploy.sh (uninstall script)
#!/bin/bash

echo "🗑️ Uninstalling all resources..."

kubectl delete -f ../k8s/ingress.yaml --ignore-not-found
kubectl delete -f ../k8s/order-service/ --ignore-not-found
kubectl delete -f ../k8s/stock-service/ --ignore-not-found
kubectl delete -f ../k8s/point-service/ --ignore-not-found
kubectl delete -f ../k8s/nacos/ --ignore-not-found
kubectl delete -f ../k8s/configmap.yaml --ignore-not-found
kubectl delete -f ../k8s/secrets.yaml --ignore-not-found

echo "✅ Uninstall completed"

# status.sh (status check script)
#!/bin/bash

echo "📊 Kubernetes cluster status"
echo "========================"

echo "Pods:"
kubectl get pods -n teaching-cloud

echo ""
echo "Services:"
kubectl get svc -n teaching-cloud

echo ""
echo "Deployments:"
kubectl get deployments -n teaching-cloud

echo ""
echo "HorizontalPodAutoscalers:"
kubectl get hpa -n teaching-cloud

echo ""
echo "Ingress:"
kubectl get ingress -n teaching-cloud

6. Common Operational Commands

# View Pod logs
kubectl logs -f deployment/order-service -n teaching-cloud

# Enter container for debugging
kubectl exec -it deployment/order-service -n teaching-cloud -- /bin/sh

# Manually scale
kubectl scale deployment order-service -n teaching-cloud --replicas=5

# Rolling restart
kubectl rollout restart deployment/order-service -n teaching-cloud

# Check rolling update status
kubectl rollout status deployment/order-service -n teaching-cloud

# Roll back to previous version
kubectl rollout undo deployment/order-service -n teaching-cloud

# Port forwarding (local debugging)
kubectl port-forward service/order-service 8081:8081 -n teaching-cloud

7. Validation Steps

# 1. Check Pod status
kubectl get pods -n teaching-cloud

# 2. Check services
kubectl get svc -n teaching-cloud

# 3. Port forwarding test
kubectl port-forward service/order-service 8081:8081 -n teaching-cloud &

# 4. Test API
curl -X POST http://localhost:8081/api/order/create \
  -H "Content-Type: application/json" \
  -d '{"userId":1,"productId":100,"quantity":2,"amount":198}'

8. Next Episode Preview

Spring Cloud Microservices – Revised Edition (12): Load testing, performance bottleneck analysis, parameter tuning, and full‑series pitfall recap.