Docker와 Kubernetes는 현대적인 애플리케이션 배포의 표준이 되었다. 이 글은 Docker 컨테이너화부터 Kubernetes 클러스터 배포까지 실전 예제와 함께 완벽하게 정리한다.
\n# Node.js 애플리케이션 예시\nFROM node:18-alpine AS builder\n\n# 작업 디렉토리 설정\nWORKDIR /app\n\n# 의존성 파일 복사\nCOPY package*.json ./\n\n# 의존성 설치\nRUN npm ci --only=production\n\n# 소스 코드 복사\nCOPY . .\n\n# 빌드\nRUN npm run build\n\n# 프로덕션 이미지\nFROM node:18-alpine\n\nWORKDIR /app\n\n# 빌드된 파일만 복사\nCOPY --from=builder /app/dist ./dist\nCOPY --from=builder /app/node_modules ./node_modules\nCOPY --from=builder /app/package*.json ./\n\n# 비root 사용자로 실행\nRUN addgroup -g 1001 -S nodejs && \\\n adduser -S nodejs -u 1001\nUSER nodejs\n\n# 포트 노출\nEXPOSE 3000\n\n# 애플리케이션 실행\nCMD [\"node\", \"dist/index.js\"]# Go 애플리케이션 예시\n# 빌드 스테이지\nFROM golang:1.21-alpine AS builder\n\nWORKDIR /build\n\n# 의존성 다운로드\nCOPY go.mod go.sum ./\nRUN go mod download\n\n# 소스 코드 복사 및 빌드\nCOPY . .\nRUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .\n\n# 실행 스테이지\nFROM alpine:latest\n\nRUN apk --no-cache add ca-certificates\n\nWORKDIR /root/\n\n# 빌드된 바이너리만 복사\nCOPY --from=builder /build/app .\n\nEXPOSE 8080\n\nCMD [\"./app\"]FROM python:3.11-slim\n\nWORKDIR /app\n\n# 시스템 의존성 설치\nRUN apt-get update && apt-get install -y \\\n gcc \\\n && rm -rf /var/lib/apt/lists/*\n\n# Python 의존성 설치\nCOPY requirements.txt .\nRUN pip install --no-cache-dir -r requirements.txt\n\n# 애플리케이션 코드 복사\nCOPY . .\n\n# 환경 변수 설정\nENV PYTHONUNBUFFERED=1\nENV FLASK_APP=app.py\n\nEXPOSE 5000\n\nCMD [\"gunicorn\", \"--bind\", \"0.0.0.0:5000\", \"app:app\"]# .dockerignore 파일\nnode_modules\nnpm-debug.log\n.git\n.gitignore\n.env\n*.md\n.DS_Store\n\n# 최적화된 Dockerfile\nFROM node:18-alpine AS deps\nWORKDIR /app\nCOPY package*.json ./\nRUN npm ci --only=production && npm cache clean --force\n\nFROM node:18-alpine AS builder\nWORKDIR /app\nCOPY package*.json ./\nRUN npm ci\nCOPY . .\nRUN npm run build\n\nFROM node:18-alpine\nWORKDIR /app\nENV NODE_ENV=production\nCOPY --from=deps /app/node_modules ./node_modules\nCOPY --from=builder /app/dist ./dist\nCOPY --from=builder /app/package.json ./\nEXPOSE 3000\nCMD [\"node\", \"dist/index.js\"]version: '3.8'\n\nservices:\n web:\n build: .\n ports:\n - \"3000:3000\"\n environment:\n - NODE_ENV=production\n - DATABASE_URL=postgresql://user:password@db:5432/mydb\n depends_on:\n - db\n - redis\n volumes:\n - ./logs:/app/logs\n\n db:\n image: postgres:15-alpine\n environment:\n - POSTGRES_USER=user\n - POSTGRES_PASSWORD=password\n - POSTGRES_DB=mydb\n volumes:\n - postgres_data:/var/lib/postgresql/data\n ports:\n - \"5432:5432\"\n\n redis:\n image: redis:7-alpine\n ports:\n - \"6379:6379\"\n volumes:\n - redis_data:/data\n\nvolumes:\n postgres_data:\n redis_data:version: '3.8'\n\nservices:\n web:\n build:\n context: .\n dockerfile: Dockerfile.dev\n ports:\n - \"3000:3000\"\n volumes:\n - .:/app\n - /app/node_modules\n environment:\n - NODE_ENV=development\n command: npm run dev\n\n db:\n image: postgres:15-alpine\n environment:\n - POSTGRES_USER=dev\n - POSTGRES_PASSWORD=dev\n - POSTGRES_DB=devdb\n ports:\n - \"5432:5432\"\n volumes:\n - ./init.sql:/docker-entrypoint-initdb.d/init.sql\n\n redis:\n image: redis:7-alpine\n ports:\n - \"6379:6379\"version: '3.8'\n\nservices:\n web:\n build: .\n restart: always\n ports:\n - \"80:3000\"\n environment:\n - NODE_ENV=production\n deploy:\n replicas: 3\n resources:\n limits:\n cpus: '0.5'\n memory: 512M\n reservations:\n cpus: '0.25'\n memory: 256M\n networks:\n - app-network\n\n nginx:\n image: nginx:alpine\n ports:\n - \"443:443\"\n volumes:\n - ./nginx.conf:/etc/nginx/nginx.conf\n - ./ssl:/etc/nginx/ssl\n depends_on:\n - web\n networks:\n - app-network\n\nnetworks:\n app-network:\n driver: bridgeapiVersion: v1\nkind: Pod\nmetadata:\n name: my-app\n labels:\n app: my-app\n version: v1\nspec:\n containers:\n - name: app\n image: my-app:1.0.0\n ports:\n - containerPort: 3000\n env:\n - name: NODE_ENV\n value: \"production\"\n - name: DATABASE_URL\n valueFrom:\n secretKeyRef:\n name: db-secret\n key: url\n resources:\n requests:\n memory: \"256Mi\"\n cpu: \"250m\"\n limits:\n memory: \"512Mi\"\n cpu: \"500m\"apiVersion: apps/v1\nkind: Deployment\nmetadata:\n name: my-app\n labels:\n app: my-app\nspec:\n replicas: 3\n selector:\n matchLabels:\n app: my-app\n template:\n metadata:\n labels:\n app: my-app\n spec:\n containers:\n - name: app\n image: my-app:1.0.0\n ports:\n - containerPort: 3000\n livenessProbe:\n httpGet:\n path: /health\n port: 3000\n initialDelaySeconds: 30\n periodSeconds: 10\n readinessProbe:\n httpGet:\n path: /ready\n port: 3000\n initialDelaySeconds: 5\n periodSeconds: 5\n resources:\n requests:\n memory: \"256Mi\"\n cpu: \"250m\"\n limits:\n memory: \"512Mi\"\n cpu: \"500m\"apiVersion: v1\nkind: Service\nmetadata:\n name: my-app-service\nspec:\n selector:\n app: my-app\n ports:\n - protocol: TCP\n port: 80\n targetPort: 3000\n type: LoadBalancer# ConfigMap\napiVersion: v1\nkind: ConfigMap\nmetadata:\n name: app-config\ndata:\n NODE_ENV: \"production\"\n LOG_LEVEL: \"info\"\n API_TIMEOUT: \"30\"\n\n---\n# Secret\napiVersion: v1\nkind: Secret\nmetadata:\n name: db-secret\ntype: Opaque\nstringData:\n url: \"postgresql://user:password@db:5432/mydb\"\n username: \"user\"\n password: \"password\"apiVersion: autoscaling/v2\nkind: HorizontalPodAutoscaler\nmetadata:\n name: my-app-hpa\nspec:\n scaleTargetRef:\n apiVersion: apps/v1\n kind: Deployment\n name: my-app\n minReplicas: 3\n maxReplicas: 10\n metrics:\n - type: Resource\n resource:\n name: cpu\n target:\n type: Utilization\n averageUtilization: 70\n - type: Resource\n resource:\n name: memory\n target:\n type: Utilization\n averageUtilization: 80apiVersion: networking.k8s.io/v1\nkind: Ingress\nmetadata:\n name: my-app-ingress\n annotations:\n kubernetes.io/ingress.class: nginx\n cert-manager.io/cluster-issuer: letsencrypt-prod\nspec:\n tls:\n - hosts:\n - api.example.com\n secretName: api-tls\n rules:\n - host: api.example.com\n http:\n paths:\n - path: /\n pathType: Prefix\n backend:\n service:\n name: my-app-service\n port:\n number: 80apiVersion: v1\nkind: PersistentVolumeClaim\nmetadata:\n name: app-storage\nspec:\n accessModes:\n - ReadWriteOnce\n resources:\n requests:\n storage: 10Gi\n storageClassName: fast-ssd# Job\napiVersion: batch/v1\nkind: Job\nmetadata:\n name: data-migration\nspec:\n template:\n spec:\n containers:\n - name: migrator\n image: migrator:1.0.0\n command: [\"node\", \"migrate.js\"]\n restartPolicy: Never\n backoffLimit: 3\n\n---\n# CronJob\napiVersion: batch/v1\nkind: CronJob\nmetadata:\n name: daily-backup\nspec:\n schedule: \"0 2 * * *\" # 매일 오전 2시\n jobTemplate:\n spec:\n template:\n spec:\n containers:\n - name: backup\n image: backup:1.0.0\n command: [\"sh\", \"backup.sh\"]\n restartPolicy: OnFailureapiVersion: apps/v1\nkind: Deployment\nmetadata:\n name: my-app\nspec:\n replicas: 5\n strategy:\n type: RollingUpdate\n rollingUpdate:\n maxSurge: 2\n maxUnavailable: 1\n selector:\n matchLabels:\n app: my-app\n template:\n metadata:\n labels:\n app: my-app\n spec:\n containers:\n - name: app\n image: my-app:2.0.0# Blue Deployment\napiVersion: apps/v1\nkind: Deployment\nmetadata:\n name: my-app-blue\nspec:\n replicas: 3\n selector:\n matchLabels:\n app: my-app\n version: blue\n template:\n metadata:\n labels:\n app: my-app\n version: blue\n spec:\n containers:\n - name: app\n image: my-app:1.0.0\n\n---\n# Green Deployment\napiVersion: apps/v1\nkind: Deployment\nmetadata:\n name: my-app-green\nspec:\n replicas: 3\n selector:\n matchLabels:\n app: my-app\n version: green\n template:\n metadata:\n labels:\n app: my-app\n version: green\n spec:\n containers:\n - name: app\n image: my-app:2.0.0\n\n---\n# Service (트래픽 전환)\napiVersion: v1\nkind: Service\nmetadata:\n name: my-app-service\nspec:\n selector:\n app: my-app\n version: blue # green으로 변경하여 트래픽 전환\n ports:\n - port: 80\n targetPort: 3000# Stable Deployment\napiVersion: apps/v1\nkind: Deployment\nmetadata:\n name: my-app-stable\nspec:\n replicas: 9\n selector:\n matchLabels:\n app: my-app\n version: stable\n template:\n metadata:\n labels:\n app: my-app\n version: stable\n spec:\n containers:\n - name: app\n image: my-app:1.0.0\n\n---\n# Canary Deployment\napiVersion: apps/v1\nkind: Deployment\nmetadata:\n name: my-app-canary\nspec:\n replicas: 1\n selector:\n matchLabels:\n app: my-app\n version: canary\n template:\n metadata:\n labels:\n app: my-app\n version: canary\n spec:\n containers:\n - name: app\n image: my-app:2.0.0apiVersion: apps/v1\nkind: Deployment\nmetadata:\n name: my-app\nspec:\n template:\n spec:\n containers:\n - name: app\n image: my-app:1.0.0\n livenessProbe:\n httpGet:\n path: /health\n port: 3000\n initialDelaySeconds: 30\n periodSeconds: 10\n timeoutSeconds: 5\n failureThreshold: 3\n readinessProbe:\n httpGet:\n path: /ready\n port: 3000\n initialDelaySeconds: 5\n periodSeconds: 5\n timeoutSeconds: 3\n failureThreshold: 2\n startupProbe:\n httpGet:\n path: /startup\n port: 3000\n initialDelaySeconds: 0\n periodSeconds: 10\n failureThreshold: 30apiVersion: v1\nkind: Service\nmetadata:\n name: my-app-service\n annotations:\n prometheus.io/scrape: \"true\"\n prometheus.io/port: \"3000\"\n prometheus.io/path: \"/metrics\"\nspec:\n selector:\n app: my-app\n ports:\n - port: 80\n targetPort: 3000apiVersion: apps/v1\nkind: Deployment\nmetadata:\n name: my-app\nspec:\n template:\n spec:\n securityContext:\n runAsNonRoot: true\n runAsUser: 1000\n fsGroup: 2000\n containers:\n - name: app\n image: my-app:1.0.0\n securityContext:\n allowPrivilegeEscalation: false\n readOnlyRootFilesystem: true\n capabilities:\n drop:\n - ALL\n add:\n - NET_BIND_SERVICEapiVersion: networking.k8s.io/v1\nkind: NetworkPolicy\nmetadata:\n name: my-app-network-policy\nspec:\n podSelector:\n matchLabels:\n app: my-app\n policyTypes:\n - Ingress\n - Egress\n ingress:\n - from:\n - podSelector:\n matchLabels:\n app: nginx\n ports:\n - protocol: TCP\n port: 3000\n egress:\n - to:\n - podSelector:\n matchLabels:\n app: db\n ports:\n - protocol: TCP\n port: 5432# namespace.yaml\napiVersion: v1\nkind: Namespace\nmetadata:\n name: production\n\n---\n# deployment.yaml\napiVersion: apps/v1\nkind: Deployment\nmetadata:\n name: my-app\n namespace: production\nspec:\n replicas: 3\n selector:\n matchLabels:\n app: my-app\n template:\n metadata:\n labels:\n app: my-app\n spec:\n containers:\n - name: app\n image: my-app:1.0.0\n ports:\n - containerPort: 3000\n env:\n - name: DATABASE_URL\n valueFrom:\n secretKeyRef:\n name: db-secret\n key: url\n - name: REDIS_URL\n valueFrom:\n configMapKeyRef:\n name: app-config\n key: redis-url\n resources:\n requests:\n memory: \"256Mi\"\n cpu: \"250m\"\n limits:\n memory: \"512Mi\"\n cpu: \"500m\"\n\n---\n# service.yaml\napiVersion: v1\nkind: Service\nmetadata:\n name: my-app-service\n namespace: production\nspec:\n selector:\n app: my-app\n ports:\n - port: 80\n targetPort: 3000\n type: ClusterIP\n\n---\n# ingress.yaml\napiVersion: networking.k8s.io/v1\nkind: Ingress\nmetadata:\n name: my-app-ingress\n namespace: production\nspec:\n rules:\n - host: api.example.com\n http:\n paths:\n - path: /\n pathType: Prefix\n backend:\n service:\n name: my-app-service\n port:\n number: 80name: Build and Deploy\n\non:\n push:\n branches: [main]\n\njobs:\n build:\n runs-on: ubuntu-latest\n steps:\n - uses: actions/checkout@v3\n \n - name: Build Docker image\n run: |\n docker build -t my-app:${{ github.sha }} .\n docker tag my-app:${{ github.sha }} my-app:latest\n \n - name: Push to registry\n run: |\n echo \"${{ secrets.DOCKER_PASSWORD }}\" | docker login -u \"${{ secrets.DOCKER_USERNAME }}\" --password-stdin\n docker push my-app:${{ github.sha }}\n docker push my-app:latest\n \n - name: Deploy to Kubernetes\n run: |\n kubectl set image deployment/my-app app=my-app:${{ github.sha }} -n production# Pod 상태 확인\nkubectl get pods\n\n# Pod 로그 확인\nkubectl logs <pod-name>\n\n# Pod 상세 정보\nkubectl describe pod <pod-name>\n\n# 컨테이너 내부 접속\nkubectl exec -it <pod-name> -- /bin/sh\n\n# 리소스 사용량 확인\nkubectl top pods\nkubectl top nodes\n\n# 이벤트 확인\nkubectl get events --sort-by=.metadata.creationTimestamp# Deployment 롤아웃 상태\nkubectl rollout status deployment/my-app\n\n# 이전 버전으로 롤백\nkubectl rollout undo deployment/my-app\n\n# 특정 리비전으로 롤백\nkubectl rollout undo deployment/my-app --to-revision=2\n\n# 리소스 YAML 확인\nkubectl get deployment my-app -o yaml\n\n# 포트 포워딩\nkubectl port-forward pod/<pod-name> 3000:3000Docker와 Kubernetes는 현대적인 애플리케이션 배포의 핵심 도구다. 이 글에서 다룬 내용:
\n이러한 도구와 패턴을 적절히 활용하면 안정적이고 확장 가능한 애플리케이션을 배포할 수 있다.
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