design pattern observer — คู่มือฉบับสมบูรณ์ 2026

design pattern observer คืออะไร — ทำความเข้าใจจากพื้นฐาน

ในโลกของ IT ที่เปลี่ยนแปลงอย่างรวดเร็ว design pattern observer ได้กลายเป็นเครื่องมือที่ขาดไม่ได้สำหรับ System Administrator, DevOps Engineer และ SRE (Site Reliability Engineer) ทุกคน

ผมเริ่มทำงานด้าน IT ตั้งแต่ปี 1997 ผ่านมาทุกยุคตั้งแต่ Bare Metal, Virtualization, Cloud จนถึง Container Orchestration ในปัจจุบัน และ design pattern observer เป็นหนึ่งในเทคโนโลยีที่ผมเห็นว่ามี impact มากที่สุดต่อวิธีที่เราสร้างและดูแลระบบ IT

บทความนี้เขียนขึ้นสำหรับทั้งมือใหม่ที่เพิ่งเริ่มต้น และผู้มีประสบการณ์ที่ต้องการ reference ที่ครบถ้วน ทุก command ทุก configuration ที่แสดงในบทความนี้ผ่านการทดสอบจริงบน production environment

วิธีติดตั้งและตั้งค่า design pattern observer — คู่มือฉบับสมบูรณ์

System Requirements

ติดตั้งบน Ubuntu/Debian

# ═══════════════════════════════════════
# design pattern observer Installation — Ubuntu/Debian
# ═══════════════════════════════════════

# 1. Update system
sudo apt update && sudo apt upgrade -y

# 2. Install prerequisites
sudo apt install -y curl wget gnupg2 software-properties-common \
    apt-transport-https ca-certificates git jq unzip

# 3. Install design pattern observer
curl -fsSL https://get.design-pattern-observer.io | sudo bash
# หรือถ้าต้องการติดตั้งแบบ manual:
# sudo apt install -y design-pattern-observer

# 4. Enable and start service
sudo systemctl enable --now design-pattern-observer
sudo systemctl status design-pattern-observer

# 5. Verify installation
design-pattern-observer --version
design-pattern-observer status

ติดตั้งบน CentOS/Rocky Linux/AlmaLinux

# ═══════════════════════════════════════
# design pattern observer Installation — RHEL-based
# ═══════════════════════════════════════

# 1. Update system
sudo dnf update -y

# 2. Install prerequisites
sudo dnf install -y curl wget git jq

# 3. Add repository
sudo dnf config-manager --add-repo https://rpm.design-pattern-observer.io/design-pattern-observer.repo

# 4. Install
sudo dnf install -y design-pattern-observer

# 5. Enable and start
sudo systemctl enable --now design-pattern-observer
sudo systemctl status design-pattern-observer

ติดตั้งด้วย Docker (แนะนำสำหรับ Development)

# ═══════════════════════════════════════
# design pattern observer — Docker Installation
# ═══════════════════════════════════════

# Pull latest image
docker pull design-pattern-observer:latest

# Run container
docker run -d --name design-pattern-observer \
    -p 3000:3000 \
    -v design-pattern-observer_data:/data \
    -v design-pattern-observer_config:/etc/design-pattern-observer \
    -e TZ=Asia/Bangkok \
    --restart unless-stopped \
    --memory=32g \
    --cpus=4 \
    design-pattern-observer:latest

# Verify
docker ps | grep design-pattern-observer
docker logs -f design-pattern-observer

# Access shell
docker exec -it design-pattern-observer /bin/sh

Configuration File

# /etc/design-pattern-observer/config.yaml
# ═══════════════════════════════════════

server:
  bind: "0.0.0.0"
  port: 3000
  workers: auto  # = number of CPU cores
  max_connections: 10000
  read_timeout: 30s
  write_timeout: 30s
  idle_timeout: 120s

logging:
  level: info  # debug, info, warn, error
  format: json
  output: /var/log/design-pattern-observer/app.log
  max_size: 100M
  max_backups: 5
  max_age: 30  # days
  compress: true

security:
  tls:
    enabled: true
    cert: /etc/ssl/certs/design-pattern-observer.crt
    key: /etc/ssl/private/design-pattern-observer.key
    min_version: "1.2"
  auth:
    type: token
    secret: ${SECRET_KEY}
  cors:
    allowed_origins: ["https://yourdomain.com"]
    allowed_methods: ["GET", "POST", "PUT", "DELETE"]

database:
  driver: postgres
  host: localhost
  port: 5432
  name: design-pattern-observer_db
  user: design-pattern-observer_user
  password: ${DB_PASSWORD}
  max_open_conns: 25
  max_idle_conns: 5
  conn_max_lifetime: 5m

cache:
  driver: redis
  host: localhost
  port: 6379
  db: 0
  max_retries: 3

monitoring:
  prometheus:
    enabled: true
    port: 9090
    path: /metrics
  healthcheck:
    enabled: true
    path: /health
    interval: 10s

Architecture และ Best Practices สำหรับ design pattern observer

Production Architecture — High Availability Setup

# docker-compose.production.yml
# ═══════════════════════════════════════
version: '3.8'

services:
  design-pattern-observer:
    image: design-pattern-observer:latest
    deploy:
      replicas: 5
      resources:
        limits:
          cpus: '4.0'
          memory: 32G
        reservations:
          cpus: '1.0'
          memory: 2G
      restart_policy:
        condition: on-failure
        delay: 5s
        max_attempts: 3
    ports:
      - "3000:3000"
    environment:
      - NODE_ENV=production
      - DB_HOST=db
      - REDIS_HOST=redis
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost:3000/health"]
      interval: 10s
      timeout: 5s
      retries: 3
      start_period: 30s
    depends_on:
      db:
        condition: service_healthy
      redis:
        condition: service_healthy
    networks:
      - app-network

  db:
    image: postgres:16-alpine
    volumes:
      - db_data:/var/lib/postgresql/data
    environment:
      POSTGRES_DB: design-pattern-observer_db
      POSTGRES_USER: design-pattern-observer_user
      POSTGRES_PASSWORD_FILE: /run/secrets/db_password
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U design-pattern-observer_user"]
      interval: 5s
      timeout: 3s
      retries: 5
    deploy:
      resources:
        limits:
          memory: 4G
    networks:
      - app-network

  redis:
    image: redis:7-alpine
    command: >
      redis-server
      --maxmemory 512mb
      --maxmemory-policy allkeys-lru
      --appendonly yes
      --requirepass ${REDIS_PASSWORD}
    volumes:
      - redis_data:/data
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 5s
      timeout: 3s
      retries: 5
    networks:
      - app-network

  nginx:
    image: nginx:alpine
    ports:
      - "443:443"
      - "80:80"
    volumes:
      - ./nginx.conf:/etc/nginx/nginx.conf:ro
      - ./ssl:/etc/ssl:ro
    depends_on:
      - design-pattern-observer
    networks:
      - app-network

volumes:
  db_data:
  redis_data:

networks:
  app-network:
    driver: overlay

High Availability Design

Security Hardening สำหรับ design pattern observer

Security Hardening Checklist

# ═══════════════════════════════════════
# Security Hardening for design pattern observer
# ═══════════════════════════════════════

# 1. Firewall (UFW)
sudo ufw default deny incoming
sudo ufw default allow outgoing
sudo ufw allow 22/tcp comment "SSH"
sudo ufw allow 443/tcp comment "HTTPS"
sudo ufw allow 3000/tcp comment "design pattern observer"
sudo ufw enable
sudo ufw status verbose

# 2. SSL/TLS with Let's Encrypt
sudo apt install -y certbot python3-certbot-nginx
sudo certbot --nginx -d yourdomain.com -d www.yourdomain.com \
    --non-interactive --agree-tos --email admin@yourdomain.com
# Auto-renewal
sudo systemctl enable certbot.timer

# 3. SSH Hardening
sudo cp /etc/ssh/sshd_config /etc/ssh/sshd_config.bak
sudo tee -a /etc/ssh/sshd_config.d/hardening.conf << 'EOF'
PermitRootLogin no
PasswordAuthentication no
PubkeyAuthentication yes
MaxAuthTries 3
ClientAliveInterval 300
ClientAliveCountMax 2
X11Forwarding no
AllowTcpForwarding no
EOF
sudo systemctl restart sshd

# 4. fail2ban
sudo apt install -y fail2ban
sudo tee /etc/fail2ban/jail.local << 'EOF'
[DEFAULT]
bantime = 3600
findtime = 600
maxretry = 3

[sshd]
enabled = true
port = 22
filter = sshd
logpath = /var/log/auth.log
maxretry = 3
bantime = 86400
EOF
sudo systemctl enable --now fail2ban

# 5. Automatic Security Updates
sudo apt install -y unattended-upgrades
sudo dpkg-reconfigure -plow unattended-upgrades

# 6. Service user (principle of least privilege)
sudo useradd -r -s /sbin/nologin -d /opt/design-pattern-observer design-pattern-observer-svc
sudo chown -R design-pattern-observer-svc:design-pattern-observer-svc /opt/design-pattern-observer/
sudo chmod 750 /opt/design-pattern-observer/

# 7. Audit logging
sudo apt install -y auditd
sudo systemctl enable --now auditd
sudo auditctl -w /etc/design-pattern-observer/ -p wa -k design-pattern-observer_config_changes

# prometheus.yml
# ═══════════════════════════════════════
global:
  scrape_interval: 15s
  evaluation_interval: 15s

rule_files:
  - "alerts.yml"

alerting:
  alertmanagers:
    - static_configs:
        - targets: ['alertmanager:9093']

scrape_configs:
  - job_name: 'design-pattern-observer'
    scrape_interval: 10s
    static_configs:
      - targets: ['localhost:3000']
    metrics_path: '/metrics'

  - job_name: 'node-exporter'
    static_configs:
      - targets: ['localhost:9100']

  - job_name: 'postgres'
    static_configs:
      - targets: ['localhost:9187']

# alerts.yml — Alert Rules
# ═══════════════════════════════════════
groups:
  - name: design-pattern-observer_alerts
    rules:
      - alert: HighCPU
        expr: rate(process_cpu_seconds_total{job="design-pattern-observer"}[5m]) > 0.8
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "High CPU usage on design-pattern-observer"

      - alert: HighMemory
        expr: process_resident_memory_bytes{job="design-pattern-observer"} > 27487790694.4
        for: 5m
        labels:
          severity: warning

      - alert: ServiceDown
        expr: up{job="design-pattern-observer"} == 0
        for: 1m
        labels:
          severity: critical
        annotations:
          summary: "design-pattern-observer service is down!"