快速上手：DeviceShifu

本文将通过一个简单的“helloworld”虚拟设备的例子，来展示如何向Shifu接入设备，生成DeviceShifu，并进行操作。

参见演示视频获得操作流程演示。

Helloworld 设备

Helloworld设备只有一个功能：每次收到请求时，返回“hello world”信息。

步骤

1. 准备虚拟设备

   本次要创建的虚拟设备是一个软件应用，它每次收到HTTP GET请求时，都会返回“Hello_world from device via shifu!” 这条信息。另外，我们还将使用Shifu的数据收集功能对这条信息进行每秒一次的自动收集。

   在开发路径中，创建一个helloworld.go文件，包含如下内容:

    package main
    import (
      "fmt"
      "net/http"
    )
   
    func process_hello(w http.ResponseWriter, req *http.Request) {
      fmt.Fprintln(w, "Hello_world from device via shifu!")
    }
   
    func headers(w http.ResponseWriter, req *http.Request) {
      for name, headers := range req.Header {
        for _, header := range headers {
          fmt.Fprintf(w, "%v: %v\n", name, header)
        }
      }
    }
   
    func main() {
      http.HandleFunc("/hello", process_hello)
      http.HandleFunc("/headers", headers)
   
      http.ListenAndServe(":11111", nil)
    }

   生成 go.mod 文件:

   go mod init helloworld

   添加 Dockerfile:

   # syntax=docker/dockerfile:1
   
   FROM golang:1.17-alpine
   WORKDIR /app
   COPY go.mod ./
   RUN go mod download
   COPY *.go ./
   RUN go build -o /helloworld
   EXPOSE 11111
   CMD [ "/helloworld" ]    

   创建镜像

   docker build --tag helloworld-device:v0.0.1 .

2. 准备 EdgeDevice:

   EdgeDevice的基本信息: 假设所有配置文件都保存在 <working_dir>/helloworld-device/configuration

   Deployment 配置: helloworld-deployment.yaml

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     labels:
       app: helloworld
     name: helloworld
     namespace: devices
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: helloworld
     template:
       metadata:
         labels:
           app: helloworld
       spec:
         containers:
           - image: helloworld-device:v0.0.1
             name: helloworld
             ports:
               - containerPort: 11111

   硬件和连接信息: helloworld-edgedevice.yaml

   apiVersion: shifu.edgenesis.io/v1alpha1
   kind: EdgeDevice
   metadata:
     name: edgedevice-helloworld
     namespace: devices
   spec:
     sku: "Hello World"
     connection: Ethernet
     address: helloworld.devices.svc.cluster.local:11111
     protocol: HTTP
   status:
     edgedevicephase: "Pending"

   Service: helloworld-service.yaml

   apiVersion: v1
   kind: Service
   metadata:
     labels:
       app: helloworld
     name: helloworld
     namespace: devices
   spec:
     ports:
       - port: 11111
         protocol: TCP
         targetPort: 11111
     selector:
       app: helloworld
     type: LoadBalancer

3. 准备DeviceShifu

   使用下面的配置文件，Shifu将自动生成DeviceShifu的Pod。 假设所有配置文件都保存在 <working_dir>/helloworld-device/configuration.

   ConfigMap: deviceshifu-helloworld-configmap.yaml

   apiVersion: v1
   kind: ConfigMap
   metadata:
     name: helloworld-configmap-0.0.1
     namespace: default
   data:
   #    device name and image address
     driverProperties: |
       driverSku: Hello World
       driverImage: helloworld-device:v0.0.1
   #    available instructions
     instructions: |
       hello:
   #    telemetry retrieval methods
   #    in this example, a device_health telemetry is collected by calling hello instruction every 1 second
     telemetries: |
       device_health:
         properties:
           instruction: hello
           initialDelayMs: 1000
           intervalMs: 1000

   Deployment: deviceshifu-helloworld-deployment.yaml

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     labels:
       app: edgedevice-helloworld-deployment
     name: edgedevice-helloworld-deployment
     namespace: default
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: edgedevice-helloworld-deployment
     template:
       metadata:
         labels:
           app: edgedevice-helloworld-deployment
       spec:
         containers:
           - image: edgehub/deviceshifu-http:v0.0.1
             name: deviceshifu-http
             ports:
               - containerPort: 8080
             volumeMounts:
               - name: edgedevice-config
                 mountPath: "/etc/edgedevice/config"
                 readOnly: true
             env:
               - name: EDGEDEVICE_NAME
                 value: "edgedevice-helloworld"
               - name: EDGEDEVICE_NAMESPACE
                 value: "devices"
         volumes:
           - name: edgedevice-config
             configMap:
               name: helloworld-configmap-0.0.1
         serviceAccountName: edgedevice-mockdevice-sa   

   Service: deviceshifu-helloworld-service.yaml

   apiVersion: v1
   kind: Service
   metadata:
     labels:
       app: edgedevice-helloworld-deployment
     name: edgedevice-helloworld-service
     namespace: default
   spec:
     ports:
       - port: 80
         protocol: TCP
         targetPort: 8080
     selector:
       app: edgedevice-helloworld-deployment
     type: LoadBalancer

4. 创建 DeviceShifu

   下面的步骤都需要要求Shifu平台已经启动并且正在运行, 参见 快速上手：安装

   1. 加载刚刚构建完成的docker镜像

      kind load docker-image helloworld-device:v0.0.1

   2. 让Shifu通过配置创建DeviceShifu的Pod

      kubectl apply -f <working_dir>/helloworld-device/configuration

   3. 启动一个nginx的服务器

      kubectl run nginx --image=nginx:1.21

      现在使用kubectl来查看Pods：

      kubectl get pods --all-namespaces

      集群中应当有以下Pod:

      NAMESPACE            NAME                                                READY   STATUS    RESTARTS   AGE
      crd-system           crd-controller-manager-7bc78896b9-sq72b             2/2     Running   0          28m
      default              edgedevice-helloworld-deployment-6464b55979-hbdhr   1/1     Running   0          27m
      default              nginx                                               1/1     Running   0          8s
      devices              helloworld-5f467bf5db-f5hxh                         1/1     Running   0          25m
      kube-system          coredns-558bd4d5db-qqx92                            1/1     Running   0          30m
      kube-system          coredns-558bd4d5db-zlw8b                            1/1     Running   0          30m
      kube-system          etcd-kind-control-plane                             1/1     Running   0          30m
      kube-system          kindnet-ndrnh                                       1/1     Running   0          30m
      kube-system          kube-apiserver-kind-control-plane                   1/1     Running   0          30m
      kube-system          kube-controller-manager-kind-control-plane          1/1     Running   0          30m
      kube-system          kube-proxy-qkswm                                    1/1     Running   0          30m
      kube-system          kube-scheduler-kind-control-plane                   1/1     Running   0          30m
      local-path-storage   local-path-provisioner-547f784dff-44xnv             1/1     Running   0          30m

      查看创建的EdgeDevice：

      kubectl get edgedevice --namespace devices edgedevice-helloworld
      
      NAME                    AGE
      edgedevice-helloworld   22m

      DeviceShifu的细节信息以及状态可以通过 describe 命令获取：

      kubectl describe edgedevice --namespace devices edgedevice-helloworld

   4. 使用nginx：

      kubectl exec -it --namespace default nginx -- bash

   5. 与DeviceShifu进行交互：

      /# curl http://edgedevice-helloworld-service:80/hello

      应该得到以下输出:

      Hello_world from device via shifu!

   6. 在日志中查看收集到的数据:

      kubectl logs edgedevice-helloworld-deployment-6464b55979-hbdhr

现在 helloworld 设备已经完全整合到Shifu框架中，可以通过上述方式来通过DeviceShifu与其交互。

如果需要更新configuration，请先delete再apply configurtaion:

  /# kubectl delete -f <working_dir>/helloworld-device/configuration
  /# kubectl apply -f <working_dir>/helloworld-device/configuration