KubeEdge使用文档
KubeEdge将Kubernetes的能力延伸到了边缘场景中，为云和边缘之间的网络，应用部署和元数据同步提供基础架构支持。KubeEdge在使用上与Kubernetes保持完全一致，除此之外还扩展了对边缘设备的管理与控制。本节将通过一个简单的例子向用户演示如何通过KubeEdge完成设备边云协同任务。
1. 准备工作
选用示例：KubeEdge Counter Demo
计数器是一个伪设备，用户无需任何额外的物理设备即可运行此演示。计数器在边缘侧运行，用户可以从云侧在Web中对其进行控制，也可以从云侧在Web中获得计数器值。原理图如下：
详细文档参考：https://github.com/kubeedge/examples/tree/master/kubeedge-counter-demo
1）本示例要求KubeEdge版本必须是v1.2.1+，此次选择最新版的KubeEdge v1.8.0
[root@ke-cloud ~]# kubectl get node
NAME STATUS ROLES AGE VERSION
ke-cloud Ready master 13h v1.20.2
ke-edge1 Ready agent,edge 64s v1.19.3-kubeedge-v1.8.0
说明：本文接下来的验证将使用边缘节点ke-edge1进行，如果你参考本文进行相关验证，后续边缘节点名称的配置需要根据你的实际情况进行更改。
2）确保k8s apiserver开启了以下配置：
--insecuret-port=8080
--insecure-bind-address=0.0.0.0
可以通过修改/etc/kubernetes/manifests/kube-apiserver.yaml文件，并重启k8s-apiserver组件的pod来进行更改。
3）下载示例代码：
[root@ke-cloud ~]# git clone https://github.com/kubeedge/examples.git $GOPATH/src/github.com/kubeedge/examples
2. 创建device model和device
1）创建device model
[root@ke-cloud ~]# cd $GOPATH/src/github.com/kubeedge/examples/kubeedge-counter-demo/crds
[root@ke-cloud crds~]# kubectl create -f kubeedge-counter-model.yaml
2）创建device
根据你的实际情况修改matchExpressions：
[root@ke-cloud ~]# cd $GOPATH/src/github.com/kubeedge/examples/kubeedge-counter-demo/crds
[root@ke-cloud crds~]# vim kubeedge-counter-instance.yaml
apiVersion: devices.kubeedge.io/v1alpha1
kind: Device
metadata:
name: counter
labels:
description: 'counter'
manufacturer: 'test'
spec:
deviceModelRef:
name: counter-model
nodeSelector:
nodeSelectorTerms:
- matchExpressions:
- key: 'kubernetes.io/hostname'
operator: In
values:
- ke-edge1
status:
twins:
- propertyName: status
desired:
metadata:
type: string
value: 'OFF'
reported:
metadata:
type: string
value: '0'
[root@ke-cloud crds~]# kubectl create -f kubeedge-counter-instance.yaml
3. 部署云端应用
1）修改代码
云端应用web-controller-app用来控制边缘端的pi-counter-app应用，该程序默认监听的端口号为80，此处修改为8089，如下所示：
[root@ke-cloud ~]# cd $GOPATH/src/github.com/kubeedge/examples/kubeedge-counter-demo/web-controller-app
[root@ke-cloud web-controller-app~]# vim main.go
package main
import (
"github.com/astaxie/beego"
"github.com/kubeedge/examples/kubeedge-counter-demo/web-controller-app/controller"
)
func main() {
beego.Router("/", new(controllers.TrackController), "get:Index")
beego.Router("/track/control/:trackId", new(controllers.TrackController), "get,post:ControlTrack")
beego.Run(":8089")
}
2）构建镜像
注意：构建镜像时，请将源码拷贝到GOPATH对应的路径下，如果开启了go mod请关闭。
[root@ke-cloud web-controller-app~]# make all
[root@ke-cloud web-controller-app~]# make docker
3）部署web-controller-app
[root@ke-cloud ~]# cd $GOPATH/src/github.com/kubeedge/examples/kubeedge-counter-demo/crds
[root@ke-cloud crds~]# kubectl apply -f kubeedge-web-controller-app.yaml
4. 部署边缘端应用
边缘端的pi-counter-app应用受云端应用控制，主要与mqtt服务器通信，进行简单的计数功能。
1）修改代码与构建镜像
需要将Makefile中的GOARCH修改为amd64才能运行该容器。
[root@ke-cloud ~]# cd $GOPATH/src/github.com/kubeedge/examples/kubeedge-counter-demo/counter-mapper
[root@ke-cloud counter-mapper~]# vim Makefile
.PHONY: all pi-execute-app docker clean
all: pi-execute-app
pi-execute-app:
GOARCH=amd64 go build -o pi-counter-app main.go
docker:
docker build . -t kubeedge/kubeedge-pi-counter:v1.0.0
clean:
rm -f pi-counter-app
[root@ke-cloud counter-mapper~]# make all
[root@ke-cloud counter-mapper~]# make docker
2）部署Pi Counter App
[root@ke-cloud ~]# cd $GOPATH/src/github.com/kubeedge/examples/kubeedge-counter-demo/crds
[root@ke-cloud crds~]# kubectl apply -f kubeedge-pi-counter-app.yaml
说明：为了防止Pod的部署卡在`ContainerCreating`，这里直接通过docker save、scp和docker load命令将镜像发布到边缘端
[root@ke-cloud ~]# docker save -o kubeedge-pi-counter.tar kubeedge/kubeedge-pi-counter:v1.0.0
[root@ke-cloud ~]# scp kubeedge-pi-counter.tar root@192.168.1.56:/root
[root@ke-edge1 ~]# docker load -i kubeedge-pi-counter.tar
5. 体验Demo
现在，KubeEdge Demo的云端部分和边缘端的部分都已经部署完毕，如下：
[root@ke-cloud ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
kubeedge-counter-app-758b9b4ffd-f8qjj 1/1 Running 0 26m 192.168.1.66 ke-cloud <none> <none>
kubeedge-pi-counter-c69698d6-rb4xz 1/1 Running 0 2m 192.168.1.56 ke-edge1 <none> <none>
我们现在开始测试一下该Demo运行效果：
1）执行ON命令 在web页面上选择ON，并点击Execute，可以在edge节点上通过以下命令查看执行结果：
[root@ke-edge1 ~]# docker logs -f counter-container-id
2）查看counter STATUS 在web页面上选择STATUS，并点击Execute，会在Web页面上返回counter当前的status。
3）执行OFF命令 在web页面上选择OFF，并点击Execute，可以再edge节点上通过以下命令查看执行结果：
[root@ke-edge1 ~]# docker logs -f counter-container-id
6. 其它
1）更多的KubeEdge官方示例请参考 https://github.com/kubeedge/examples
| 名称 | 描述 |
|---|---|
| LED-RaspBerry-Pi | Controlling a LED light with Raspberry Pi using KubeEdge platform |
| Data Analysis @ Edge | Analyzing data at edge by using Apache Beam and KubeEdge |
| Security@Edge | Security at edge using SPIRE for identity management |
| Bluetooth-CC2650-demo | Controlling a CC2650 SensorTag bluetooth device using KubeEdge platform |
| Play Music @Edge through WeChat | Play music at edge based on WeChat and KubeEdge |
| Play Music @Edge through Web | Play music at edge based on Web and KubeEdge |
| Collecting temperature @Edge | Collecting temperature at edge based KubeEdge |
| Control pseudo device counter and collect data | Control pseudo device counter and collect data based KubeEdge |
| Play Music @Edge through Twitter | Play music at edge based on Twitter and KubeEdge. |
| Control Zigbee @Edge through cloud | Face detection at cloud using OpenCV and using it to control zigbee on edge using Kubeedge. |
2）使用EdgeMesh做边缘服务发现
https://github.com/kubeedge/edgemesh
3）自定义云边消息路由
https://kubeedge.io/en/docs/developer/custom_message_deliver/
