Kubernetes對Java應用部署的自動化驗證流程

在Kubernetes環境中部署Java應用程序后，進行自動化驗證是確保應用正常運行的關鍵步驟。以下是一個典型的自動化驗證流程，涵蓋了從部署到驗證的各個階段：

1. 部署Java應用程序到Kubernetes集群

首先，你需要將Java應用程序打包成Docker鏡像，并將其推送到Docker Registry或私有倉庫。然后，使用Kubernetes的YAML文件定義部署、服務和Ingress資源。

# deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: java-app
spec:
  replicas: 3
  selector:
    matchLabels:
      app: java-app
  template:
    metadata:
      labels:
        app: java-app
    spec:
      containers:
      - name: java-app
        image: your-docker-registry/java-app:latest
        ports:
        - containerPort: 8080

2. 配置Kubernetes服務

創建一個Service資源，以便將外部流量路由到你的Java應用程序。

# service.yaml
apiVersion: v1
kind: Service
metadata:
  name: java-app-service
spec:
  selector:
    app: java-app
  ports:
    - protocol: TCP
      port: 80
      targetPort: 8080
  type: LoadBalancer

3. 配置Ingress（可選）

如果你需要將應用程序暴露給外部網絡，可以使用Ingress資源。

# ingress.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: java-app-ingress
spec:
  rules:
  - host: yourdomain.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: java-app-service
            port:
              number: 80

4. 自動化部署腳本

編寫一個腳本來自動化上述YAML文件的創建和應用。

#!/bin/bash

# Deploy the application
kubectl apply -f deployment.yaml
kubectl apply -f service.yaml
# Optionally, deploy the ingress
kubectl apply -f ingress.yaml

# Wait for the application to be ready
sleep 30

# Verify the application is running
kubectl get pods
kubectl get services
# Optionally, verify the ingress
kubectl get ingress

5. 自動化驗證腳本

編寫一個腳本來驗證Java應用程序是否正常運行。

#!/bin/bash

# Check if the application is running
APP_NAME="java-app"
POD_NAME=$(kubectl get pods | grep $APP_NAME | awk '{print $1}')

if kubectl get pod $POD_NAME -o jsonpath='{.status.phase}' | grep -q Running; then
  echo "Application is running successfully."
else
  echo "Application is not running. Status: $(kubectl get pod $POD_NAME -o jsonpath='{.status.phase}')"
  exit 1
fi

# Optionally, check the service endpoint
SERVICE_IP=$(kubectl get service $APP_NAME-service -o jsonpath='{.status.clusterIP}')
if curl -s http://$SERVICE_IP:80 | grep -q "Welcome to Java App"; then
  echo "Service endpoint is working."
else
  echo "Service endpoint is not working."
  exit 1
fi

# Optionally, check the ingress
INGRESS_IP=$(kubectl get ingress $APP_NAME-ingress -o jsonpath='{.status.loadBalancer.ingress[0].ip}')
if curl -s http://$INGRESS_IP | grep -q "Welcome to Java App"; then
  echo "Ingress is working."
else
  echo "Ingress is not working."
  exit 1
fi

6. 集成CI/CD管道

將上述腳本集成到你的CI/CD管道中，例如Jenkins、GitLab CI或GitHub Actions。

# Example GitHub Actions workflow
name: Deploy and Verify Java App

on:
  push:
    branches:
      - main

jobs:
  deploy-and-verify:
    runs-on: ubuntu-latest
    steps:
    - name: Checkout code
      uses: actions/checkout@v2

    - name: Set up JDK 11
      uses: actions/setup-java@v2
      with:
        java-version: '11'
        distribution: 'adopt'

    - name: Build with Gradle
      run: ./gradlew build

    - name: Create Docker image
      run: ./gradlew shadowJar
      env:
        DOCKER_USER: ${{ secrets.DOCKER_USER }}
        DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}

    - name: Push Docker image
      run: |
        echo ${{ secrets.DOCKER_PASSWORD }} | docker login -u ${{ secrets.DOCKER_USER }} --password-stdin
        docker push your-docker-registry/java-app:latest

    - name: Deploy to Kubernetes
      run: kubectl apply -f deployment.yaml
      env:
        KUBECONFIG: ${{ secrets.KUBECONFIG }}

    - name: Verify deployment
      run: ./verify-deployment.sh

通過上述流程，你可以實現Java應用程序在Kubernetes環境中的自動化部署和驗證。