Azure IoT Hub DPS custom allocation policies by functions- 在DPS中啓用設備自定義分配策略
視頻介紹：
azure iot hub DPS 自定義策略
圖文介紹：
本問參考官網文檔：https://docs.microsoft.com/zh-cn/azure/iot-dps/how-to-use-custom-allocation-policies
在實際的業務中，可能存在某個DPS服務根據特定的策略將設備分配到不同的Azure IoT Hub 的情況，比如：
1. 大型項目中，將不同客戶的設備分配到該客戶獨有的IoT Hub中；
2. 根據硬件版本號，將V1.1的版本號分配到中國東部2的IoT Hub，將V1.2的分配到中國北部的IoT Hub；
3. 根據硬件種類，將冰箱分配到冰箱專用的IoT Hub, 將空調分配到空調專用的IoT Hub；
4. 其他場景
這時候的這個分配規則，就是自定義規則，通過Azure functions實現，示意圖如下：
本例中，
1. 創建了兩個IoT Hub，一個是冰箱專用的，Hub名稱包含 fridge字樣，一個是空調專用的，hub名稱包含conditioner字樣；
2. 1個DPS服務，鏈接了上述兩個IoT Hub, 配置了一個Function 自定義分配規則；
3. 1個function app，通過http觸發，規則如上述圖片所示；
4. 使用示例代碼(C#)模擬設備進行測試，下載鏈接：https://codeload.github.com/Azure-Samples/azure-iot-samples-csharp/zip/master
重點步驟：
1.創建兩個IoT Hub, 一個是冰箱專用的，Hub名稱包含 fridge字樣，一個是空調專用的，hub名稱包含conditioner字樣
2. 創建1個DPS服務
3.鏈接兩個IoT Hub:
4. 準備Functions, Http 觸發：
引用如下包：
<PackageReference Include="Microsoft.Azure.Devices.Provisioning.Service" Version="1.5.0" />
<PackageReference Include="Microsoft.Azure.Devices.Shared" Version="1.16.0" />
代碼如下：
using System;
using System.IO;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;
using Microsoft.Azure.Devices.Shared; // For TwinCollection
using Microsoft.Azure.Devices.Provisioning.Service; // For TwinState
namespace Company.Function
{
public static class HttpTriggerCSharp1
{
[FunctionName("HttpTriggerCSharp1")]
public static async Task<IActionResult> Run(
[HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req,
ILogger log)
{
log.LogInformation("C# HTTP trigger function processed a request.");
// Get request body
string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
dynamic data = JsonConvert.DeserializeObject(requestBody);
log.LogInformation("Request.Body:...");
log.LogInformation(requestBody);
// Get registration ID of the device
string regId = data?.deviceRuntimeContext?.registrationId;
string message = "Uncaught error";
bool fail = false;
ResponseObj obj = new ResponseObj();
if (regId == null)
{
message = "Registration ID not provided for the device.";
log.LogInformation("Registration ID : NULL");
fail = true;
}
else
{
string[] hubs = data?.linkedHubs.ToObject<string[]>();
// Must have hubs selected on the enrollment
if (hubs == null)
{
message = "No hub group defined for the enrollment.";
log.LogInformation("linkedHubs : NULL");
fail = true;
}
else
{
// This is a air-conditioner
if (regId.Contains("-conditioner"))
{
//Find the "conditioner" IoT hub configured on the enrollment
foreach(string hubString in hubs)
{
if (hubString.Contains("-conditioner"))
obj.iotHubHostName = hubString;
}
if (obj.iotHubHostName == null)
{
message = "No conditioner hub found for the enrollment.";
log.LogInformation(message);
fail = true;
}
else
{
// Specify the initial tags for the device.
TwinCollection tags = new TwinCollection();
tags["deviceType"] = "conditioner";
// Specify the initial desired properties for the device.
TwinCollection properties = new TwinCollection();
properties["state"] = "code";
// Add the initial twin state to the response.
TwinState twinState = new TwinState(tags, properties);
obj.initialTwin = twinState;
}
}
// This is fridge
else if (regId.Contains("-fridge"))
{
//Find the "-heatpumps-" IoT hub configured on the enrollment
foreach(string hubString in hubs)
{
if (hubString.Contains("-fridge"))
obj.iotHubHostName = hubString;
}
if (obj.iotHubHostName == null)
{
message = "No fridge hub found for the enrollment.";
log.LogInformation(message);
fail = true;
}
else
{
// Specify the initial tags for the device.
TwinCollection tags = new TwinCollection();
tags["deviceType"] = "fridge";
// Specify the initial desired properties for the device.
TwinCollection properties = new TwinCollection();
properties["state"] = "on";
properties["temperatureSetting"] = "-18";
// Add the initial twin state to the response.
TwinState twinState = new TwinState(tags, properties);
obj.initialTwin = twinState;
}
}
// Unrecognized device.
else
{
fail = true;
message = "Unrecognized device registration.";
log.LogInformation("Unknown device registration");
}
}
}
log.LogInformation("\nResponse");
log.LogInformation((obj.iotHubHostName != null) ? JsonConvert.SerializeObject(obj) : message);
return (fail)
? new BadRequestObjectResult(message)
: (ActionResult)new OkObjectResult(obj);
}
}
public class ResponseObj
{
public string iotHubHostName {get; set;}
public TwinState initialTwin {get; set;}
}
}
發佈Function:
5. 在DPS中創建組註冊，策略選擇自定義function，IoT Hub 選擇冰箱和空調兩個
6. 運行設備示例代碼：
修改idScope, primarykey,secondarykey, 可參見《DPS 組註冊示例》
其中registrationId 也就是註冊到iot hub後的設備ID，如果包含“fridge”則註冊到冰箱iot hub，如果包含“conditioner” 則註冊到空調iot hub，
依次修改爲包含fridge和conditioner的字符串後運行程序：
7. 在iot hub中檢查結果：
同時驗證 device twin也由Function 寫好：
