istio-traffic-management

Istio 流量管理

面向生产服务网格部署的 Istio 流量管理综合指南。

何时使用此技能

• 配置服务到服务的路由
• 实施金丝雀或蓝绿部署
• 设置熔断器和重试
• 负载均衡配置
• 用于测试的流量镜像
• 用于混沌工程的故障注入

核心概念

1. 流量管理资源

资源	用途	作用范围
VirtualService	将流量路由到目标	基于主机
DestinationRule	在路由后定义策略	基于服务
Gateway	配置入口/出口	集群边缘
ServiceEntry	添加外部服务	网格范围

2. 流量流向

Client → Gateway → VirtualService → DestinationRule → Service
                   (routing)        (policies)        (pods)

模板

模板 1：基本路由

apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: reviews-route
  namespace: bookinfo
spec:
  hosts:
    - reviews
  http:
    - match:
        - headers:
            end-user:
              exact: jason
      route:
        - destination:
            host: reviews
            subset: v2
    - route:
        - destination:
            host: reviews
            subset: v1
---
apiVersion: networking.istio.io/v1beta1
kind: DestinationRule
metadata:
  name: reviews-destination
  namespace: bookinfo
spec:
  host: reviews
  subsets:
    - name: v1
      labels:
        version: v1
    - name: v2
      labels:
        version: v2
    - name: v3
      labels:
        version: v3

模板 2：金丝雀部署

apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: my-service-canary
spec:
  hosts:
    - my-service
  http:
    - route:
        - destination:
            host: my-service
            subset: stable
          weight: 90
        - destination:
            host: my-service
            subset: canary
          weight: 10
---
apiVersion: networking.istio.io/v1beta1
kind: DestinationRule
metadata:
  name: my-service-dr
spec:
  host: my-service
  trafficPolicy:
    connectionPool:
      tcp:
        maxConnections: 100
      http:
        h2UpgradePolicy: UPGRADE
        http1MaxPendingRequests: 100
        http2MaxRequests: 1000
  subsets:
    - name: stable
      labels:
        version: stable
    - name: canary
      labels:
        version: canary

模板 3：熔断器

apiVersion: networking.istio.io/v1beta1
kind: DestinationRule
metadata:
  name: circuit-breaker
spec:
  host: my-service
  trafficPolicy:
    connectionPool:
      tcp:
        maxConnections: 100
      http:
        http1MaxPendingRequests: 100
        http2MaxRequests: 1000
        maxRequestsPerConnection: 10
        maxRetries: 3
    outlierDetection:
      consecutive5xxErrors: 5
      interval: 30s
      baseEjectionTime: 30s
      maxEjectionPercent: 50
      minHealthPercent: 30

模板 4：重试与超时

apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: ratings-retry
spec:
  hosts:
    - ratings
  http:
    - route:
        - destination:
            host: ratings
      timeout: 10s
      retries:
        attempts: 3
        perTryTimeout: 3s
        retryOn: connect-failure,refused-stream,unavailable,cancelled,retriable-4xx,503
        retryRemoteLocalities: true

模板 5：流量镜像

apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: mirror-traffic
spec:
  hosts:
    - my-service
  http:
    - route:
        - destination:
            host: my-service
            subset: v1
      mirror:
        host: my-service
        subset: v2
      mirrorPercentage:
        value: 100.0

模板 6：故障注入

apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: fault-injection
spec:
  hosts:
    - ratings
  http:
    - fault:
        delay:
          percentage:
            value: 10
          fixedDelay: 5s
        abort:
          percentage:
            value: 5
          httpStatus: 503
      route:
        - destination:
            host: ratings

模板 7：入口网关

apiVersion: networking.istio.io/v1beta1
kind: Gateway
metadata:
  name: my-gateway
spec:
  selector:
    istio: ingressgateway
  servers:
    - port:
        number: 443
        name: https
        protocol: HTTPS
      tls:
        mode: SIMPLE
        credentialName: my-tls-secret
      hosts:
        - "*.example.com"
---
apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: my-vs
spec:
  hosts:
    - "api.example.com"
  gateways:
    - my-gateway
  http:
    - match:
        - uri:
            prefix: /api/v1
      route:
        - destination:
            host: api-service
            port:
              number: 8080

负载均衡策略

apiVersion: networking.istio.io/v1beta1
kind: DestinationRule
metadata:
  name: load-balancing
spec:
  host: my-service
  trafficPolicy:
    loadBalancer:
      simple: ROUND_ROBIN # or LEAST_CONN, RANDOM, PASSTHROUGH
---
# Consistent hashing for sticky sessions
apiVersion: networking.istio.io/v1beta1
kind: DestinationRule
metadata:
  name: sticky-sessions
spec:
  host: my-service
  trafficPolicy:
    loadBalancer:
      consistentHash:
        httpHeaderName: x-user-id
        # or: httpCookie, useSourceIp, httpQueryParameterName

最佳实践

应做

• 从简单开始 - 逐步增加复杂性
• 使用子集 - 清晰地版本化你的服务
• 设置超时 - 始终配置合理的超时
• 启用重试 - 但要有退避和限制
• 监控 - 使用 Kiali 和 Jaeger 获得可见性

不应做

• 不要过度重试 - 可能导致级联故障
• 不要忽略异常值检测 - 启用熔断器
• 不要镜像到生产环境 - 镜像到测试环境
• 不要跳过金丝雀 - 先用小流量百分比进行测试

调试命令

# Check VirtualService configuration
istioctl analyze

# View effective routes
istioctl proxy-config routes deploy/my-app -o json

# Check endpoint discovery
istioctl proxy-config endpoints deploy/my-app

# Debug traffic
istioctl proxy-config log deploy/my-app --level debug