微服务使用Istio实现服务网格

我们首先需要部署我们的go应用程序。我们可以使用以下YAML文件定义我们的部署：

apiVersion: v1
kind: Service
metadata:
  name: my-app-service
spec:
  selector:
    app: my-app
  ports:
  - name: http
    protocol: TCP
    port: 80
    targetPort: 8080
  type: NodePort
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-app
spec:
  replicas: 1
  selector:
    matchLabels:
      app: my-app
  template:
    metadata:
      labels:
        app: my-app
    spec:
      containers:
      - name: my-app
        image: xxxxxxx-image:v1
        ports:
        - containerPort: 8080

在这个YAML文件中，我们定义了一个名为“my-app”的部署，用于运行我们的go应用程序，它将在一个容器中运行，并在端口8080上暴露服务。同时定义了一个名为“my-app-service”的服务，它将指向我们的go部署，并将端口80映射到容器端口8080

kubectl apply -f deployment.yaml

把当前namespace打上istio的标签,我这里用默认

kubectl label namespace default istio-injection=enabled

定义一个Istio虚拟服务，将HTTP请求路由到我们的go应用程序：

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: my-app-virtual-service
spec:
  hosts:
  - "*"
  gateways:
  - istio-system/ingressgateway
  http:
  - match:
    - uri:
        prefix: /
    route:
    - destination:
        host: my-app-service.default.svc.cluster.local
        port:
          number: 80

为了更好地管理我们的服务网格，我们还可以使用Istio的监控和跟踪功能。例如，我们可以使用以下YAML文件定义一个Istio DestinationRule，使其启用所有传入和传出流量的跟踪和度量

apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: my-app-destination-rule
spec:
  host: my-app-service.default.svc.cluster.local
  trafficPolicy:
    tls:
      mode: ISTIO_MUTUAL
    portLevelSettings:
    - port:
        number: 80
      tls:
        mode: ISTIO_MUTUAL
    connectionPool:
      http:
        http1MaxPendingRequests: 100
        maxRequestsPerConnection: 5
      tcp:
        maxConnections: 1000
    outlierDetection:
      consecutiveErrors: 5
      interval: 5s
      baseEjectionTime: 30s
      maxEjectionPercent: 50

PS：或者Gateway与VirtualService分开部署,感觉合并到一起更方便

Gateway

# gateway
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: jgrpc
spec:
  selector:
    istio: ingressgateway
  servers:
    - port:
        number: 80
        name: http
        protocol: HTTP
      hosts:
        - "dev.api.your-domain.com"

VirtualService

# virtual service
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: jgrpc
spec:
  hosts:
    - "dev.api.your-domain.com"
  gateways:
    - jgrpc
  http:
    - match:
        - uri:
            prefix: /
      route:
        - destination:
            port:
              number: 80
            host: ping