Selenium Grid 4 与分布式执行

# 拉取 Grid 4.41.0 Standalone Chrome 镜像（GHCR 镜像源，避免 Docker Hub 限流）
docker pull ghcr.io/seleniumhq/standalone-chrome:4.41.0

# 启动单容器 Grid（内置 Chrome 浏览器）
docker run -d -p 4444:4444 -p 7900:7900 \
  --shm-size=2g \
  ghcr.io/seleniumhq/standalone-chrome:4.41.0

# 4444：WebDriver 端点；7900：noVNC 网页查看浏览器界面
# 浏览器 http://localhost:4444/ui 查看 Grid 控制台

// Selenium 4.41 + Java 示例
ChromeOptions options = new ChromeOptions();  // Selenium 4 已废弃 DesiredCapabilities
WebDriver driver = new RemoteWebDriver(
    new URL("http://localhost:4444/wd/hub"),  // 指向 Grid，而非具体测试机
    options
);

# docker-compose.yml - Selenium Grid 4 Distributed Mode
# 版本：Selenium 4.41.0，镜像源 GHCR
services:
  # 事件总线 - 组件间通信的基础
  selenium-event-bus:
    image: ghcr.io/seleniumhq/event-bus:4.41.0
    container_name: selenium-event-bus
    ports:
      - "4442:4442"   # 事件发布端口
      - "4443:4443"   # 事件订阅端口
      - "5557:5557"   # Event Bus 服务端口

  # 会话队列 - 管理等待分配的会话请求
  selenium-session-queue:
    image: ghcr.io/seleniumhq/session-queue:4.41.0
    container_name: selenium-session-queue
    depends_on: [selenium-event-bus]
    environment:
      - SE_EVENT_BUS_HOST=selenium-event-bus
      - SE_EVENT_BUS_PUBLISH_PORT=4442
      - SE_EVENT_BUS_SUBSCRIBE_PORT=4443

  # 会话映射 - 维护 Session ID 与 Node 的映射
  selenium-sessions:
    image: ghcr.io/seleniumhq/sessions:4.41.0
    container_name: selenium-sessions
    depends_on: [selenium-event-bus]
    ports: ["5556:5556"]
    environment:
      - SE_EVENT_BUS_HOST=selenium-event-bus
      - SE_EVENT_BUS_PUBLISH_PORT=4442
      - SE_EVENT_BUS_SUBSCRIBE_PORT=4443

  # 分发器 - 将会话请求分配到合适的 Node
  selenium-distributor:
    image: ghcr.io/seleniumhq/distributor:4.41.0
    container_name: selenium-distributor
    depends_on: [selenium-event-bus, selenium-sessions, selenium-session-queue]
    ports: ["5553:5553"]
    environment:
      - SE_EVENT_BUS_HOST=selenium-event-bus
      - SE_EVENT_BUS_PUBLISH_PORT=4442
      - SE_EVENT_BUS_SUBSCRIBE_PORT=4443
      - SE_SESSIONS_MAP_HOST=selenium-sessions
      - SE_SESSIONS_MAP_PORT=5556
      - SE_SESSION_QUEUE_HOST=selenium-session-queue
      - SE_SESSION_QUEUE_PORT=5559

  # 路由器 - 系统入口，路由所有外部请求
  selenium-router:
    image: ghcr.io/seleniumhq/router:4.41.0
    container_name: selenium-router
    depends_on: [selenium-distributor, selenium-sessions, selenium-session-queue]
    ports: ["4444:4444"]
    environment:
      - SE_DISTRIBUTOR_HOST=selenium-distributor
      - SE_DISTRIBUTOR_PORT=5553
      - SE_SESSIONS_MAP_HOST=selenium-sessions
      - SE_SESSIONS_MAP_PORT=5556
      - SE_SESSION_QUEUE_HOST=selenium-session-queue
      - SE_SESSION_QUEUE_PORT=5559

  # Chrome Node - 执行 Chrome 浏览器测试
  chrome-node:
    image: ghcr.io/seleniumhq/node-chrome:4.41.0
    depends_on: [selenium-event-bus]
    environment:
      - SE_EVENT_BUS_HOST=selenium-event-bus
      - SE_EVENT_BUS_PUBLISH_PORT=4442
      - SE_EVENT_BUS_SUBSCRIBE_PORT=4443
      - SE_NODE_MAX_SESSIONS=4   # 单 Node 最大并发会话数
    shm_size: 2gb                 # 共享内存，防止浏览器 OOM
    deploy:
      replicas: 2                  # 启动 2 个 Chrome Node 实例

  # Firefox Node - 执行 Firefox 浏览器测试
  firefox-node:
    image: ghcr.io/seleniumhq/node-firefox:4.41.0
    depends_on: [selenium-event-bus]
    environment:
      - SE_EVENT_BUS_HOST=selenium-event-bus
      - SE_EVENT_BUS_PUBLISH_PORT=4442
      - SE_EVENT_BUS_SUBSCRIBE_PORT=4443
      - SE_NODE_MAX_SESSIONS=4
    shm_size: 2gb
    deploy:
      replicas: 2

# 一键启动整个 Selenium Grid 集群
docker compose up -d

# 动态扩容 Chrome Node 到 4 个实例
docker compose up -d --scale chrome-node=4

# 一键销毁整个集群
docker compose down

# 1. 添加 Selenium 官方 Chart 仓库
helm repo add selenium https://kubernetes.selenium.dev/charts
helm repo update

# 2. 创建专用命名空间（实现多团队资源隔离）
kubectl create namespace selenium-grid

# 3. 自定义 values 部署
helm install selenium-grid selenium/selenium-grid \
  --namespace selenium-grid \
  -f values-overrides.yaml

# values-overrides.yaml - Selenium Grid K8s 部署自定义配置
# 配置 Chrome Node 副本数与资源
chromeNode:
  replicas: 3                      # 初始 Chrome Node 副本数
  maxSessionsPerNode: 4            # 每 Node 最大会话数
  resources:
    requests:
      memory: "1Gi"
      cpu: "1"
    limits:
      memory: "2Gi"
      cpu: "2"

# 配置 Firefox Node
firefoxNode:
  replicas: 2
  maxSessionsPerNode: 4

# 启用 Ingress 外部访问
ingress:
  enabled: true
  hostname: selenium-grid.example.com
  annotations:
    nginx.ingress.kubernetes.io/proxy-body-size: 100m

# 启用 HPA 弹性伸缩
autoscaling:
  enabled: true
  minReplicas: 2
  maxReplicas: 20
  targetCPUUtilizationPercentage: 70

# selenium-node-deployment.yaml - Chrome Node K8s Deployment
apiVersion: apps/v1
kind: Deployment
metadata:
  name: selenium-chrome-node
  namespace: selenium-grid          # 命名空间隔离
  labels:
    app: selenium-chrome-node
    browser: chrome
spec:
  replicas: 3
  selector:
    matchLabels: { app: selenium-chrome-node }
  template:
    metadata:
      labels: { app: selenium-chrome-node, browser: chrome }
    spec:
      containers:
      - name: selenium-node
        image: ghcr.io/seleniumhq/node-chrome:4.41.0
        env:
        - name: SE_EVENT_BUS_HOST
          value: "selenium-event-bus.selenium-grid.svc.cluster.local"
        - name: SE_EVENT_BUS_PUBLISH_PORT
          value: "4442"
        - name: SE_EVENT_BUS_SUBSCRIBE_PORT
          value: "4443"
        - name: SE_NODE_MAX_SESSIONS
          value: "4"
        resources:
          requests: { memory: "1Gi", cpu: "1" }
          limits:   { memory: "2Gi", cpu: "2" }
        volumeMounts:
        - name: dshm
          mountPath: /dev/shm       # 共享内存，避免浏览器 OOM
      volumes:
      - name: dshm
        emptyDir:
          medium: Memory
          sizeLimit: 2Gi

# hpa-selenium-chrome.yaml - 基于会话队列深度自动扩缩容
apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: selenium-chrome-node-hpa
  namespace: selenium-grid
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: selenium-chrome-node
  minReplicas: 2                   # 最小副本数（保底容量）
  maxReplicas: 50                  # 最大副本数（峰值容量上限）
  metrics:
  - type: Pods
    pods:
      metric:
        name: selenium_session_queue_depth   # 自定义指标：会话队列深度
      target:
        type: AverageValue
        averageValue: "5"          # 平均每 Pod 排队 5 个会话即触发扩容
  - type: Resource
    resource:
      name: cpu
      target:
        type: Utilization
        averageUtilization: 70     # CPU 利用率超 70% 触发扩容

# 拉取 Selenoid 镜像
docker pull aerokube/selenoid:latest

# 配置浏览器镜像映射（browsers.json）
cat > browsers.json <<'EOF'
{
  "chrome": {
    "default": "latest",
    "versions": { "latest": { "image": "selenoid/chrome:latest", "port": "4444" } }
  },
  "firefox": {
    "default": "latest",
    "versions": { "latest": { "image": "selenoid/firefox:latest", "port": "4444" } }
  }
}
EOF

# 启动 Selenoid（监听 4444 端口，与 Selenium WebDriver 协议兼容）
docker run -d --name selenoid -p 4444:4444 \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -v ./browsers.json:/etc/selenoid/browsers.json \
  aerokube/selenoid:latest