Kubeedge - 5： 玩转 Router

什么是 Router

  • router 是 KubeEdge 中的一种通过实现 CRDs 来实现与边缘端进行MQTT通信的模式
  • 在 KubeEdge 中通过 Rule 和 RuleEndPoint 实现了几种通信模式

配置开启 router

云端（cloud）

  • 开启router模式
    # 如果你是通过pod安装的cloudcore 查看是否开启
    #可以通过kubectl edit pod <cloudcore_name> -n kubeedge 修改
    kubectl describe cm cloudcore -n kubeedge 
    .......
      router:
        enable: true
    .......

边缘端（edge）

  • 开启eventbus和servicebus
    vi /etc/kubeedge/config/edgecore.yaml

    metaManager:
      contextSendGroup: hub
      contextSendModule: websocket
      enable: true
      metaServer:
        enable: true
        server: 127.0.0.1:10550
        tlsCaFile: /etc/kubeedge/ca/rootCA.crt
        tlsCertFile: /etc/kubeedge/certs/server.crt
        tlsPrivateKeyFile: /etc/kubeedge/certs/server.key
      remoteQueryTimeout: 60
    serviceBus:
      enable: true
      port: 9060
      server: 127.0.0.1
      timeout: 60

什么是 EventBus 和 ServiceBus

EventBus-边缘消息

    1. 通过MQTT接收外部客户端到消息
    1. 通过MQTT发送消息

ServiceBus-边缘消息

    1. 云端通过 beehive 发送消息
    1. EdgeHub接收消息然后发送给ServiceBus
    1. ServiceBus 提供http调用然后返回消息

三大消息传递

云到边 - eventbus

    1. 用户创建源和目标的规则
    1. 云端APP调用api发送消息，消息到边缘端后通过eventbus 发布到 MQTT Broker
    1. 边缘端应用收到订阅的相关消息

云到边 - servicebus

    1. 用户创建源和目标的规则
    1. 云端 App 调用云端 api 发送消息，到达 servicebus
    1. servicebus 调用 边缘端 App 的 http API

边的 eventbus ->云

    1. 用户创建源和目标的规则
    1. 边缘应用发布消息到 MQTT Broker，eventbus 订阅消息并发布到云端
    1. 云端应用通过配置 router 中定义的规则得到上述消息

exmaple-rule and endpoint

cloud to edge : rest->eventbus

  • cloud-endpoint
    apiVersion: rules.kubeedge.io/v1
    kind: RuleEndpoint
    metadata:
      name: my-rest
      labels:
        description: test
    spec:
      ruleEndpointType: "rest"
      properties: {}
  • edge-endpoint
    apiVersion: rules.kubeedge.io/v1
    kind: RuleEndpoint
    metadata:
      name: my-eventbus
      labels:
        description: test
    spec:
      ruleEndpointType: "eventbus"
      properties: {}
  • rule
    apiVersion: rules.kubeedge.io/v1
    kind: Rule
    metadata:
      name: my-rule
      labels:
        description: test
    spec:
      source: "my-rest"
      sourceResource: {"path":"/a"}
      target: "my-eventbus"
      targetResource: {"topic":"test"}

edge to cloud: eventbus->rest

  • cloud-endpoint
      apiVersion: rules.kubeedge.io/v1
    kind: RuleEndpoint
    metadata:
      name: my-rest
      labels:
        description: test
    spec:
      ruleEndpointType: "rest"
      properties: {}
  • edge-endpoint
    apiVersion: rules.kubeedge.io/v1
    kind: RuleEndpoint
    metadata:
      name: my-eventbus
      labels:
        description: test
    spec:
      ruleEndpointType: "eventbus"
      properties: {}
  • rule
    apiVersion: rules.kubeedge.io/v1
    kind: Rule
    metadata:
      name: my-rule-eventbus-rest
      labels:
        description: test
    spec:
      source: "my-eventbus"
      sourceResource: {"topic": "test","node_name": "xxx"}
      target: "my-rest"
      targetResource: {"resource":"http://a.com"}

cloud to edge : rest->servicebus

  • cloud-endpoint
    apiVersion: rules.kubeedge.io/v1
    kind: RuleEndpoint
    metadata:
      name: my-rest
      labels:
        description: test
    spec:
      ruleEndpointType: "rest"
      properties: {}
  • edge-endpoint
    apiVersion: rules.kubeedge.io/v1
    kind: RuleEndpoint
    metadata:
      name: my-servicebus
      labels:
        description: test
    spec:
      ruleEndpointType: "servicebus"
      properties: {"service_port":"6666"}
  • rule
    apiVersion: rules.kubeedge.io/v1
    kind: Rule
    metadata:
      name: my-rule-rest-servicebus
      labels:
        description: test
    spec:
      source: "my-rest"
      sourceResource: {"path":"/a"}
      target: "my-servicebus"
      targetResource: {"path":"/b"}

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