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javascript - 尝试从 Visual Studio 代码连接到 Azure 数字孪生：DefaultAzureCredential(); .getToken 错误

问题描述

我正在尝试使用适用于 Azure 数字孪生的 Javascript API 从 Visual Studio Code 连接到 Azure Digital wins 实例。

我跑了npm install @azure/identity ，而且npm install @azure/digital-twins-core。

az login我可以使用VS Code 中的 Powershell 终端登录到 Azure 门户。它找到我的帐户和订阅并登录。

az account get-access-token --output json返回我的令牌。

这是我要运行的代码。它应该在 Azure 数字孪生实例中创建两个模型：

    const { DefaultAzureCredential } = require("@azure/identity");
    const { DigitalTwinsClient } = require("@azure/digital-twins-core");
    const { v4 } = require("uuid");
    const { inspect } = require("util");
    
    
    async function main() {
      const modelId = `dtmi:model_${v4()
        .split("-")
        .join("")};1`;
      const componentId = `dtmi:component_${v4()
        .split("-")
        .join("")};1`;
      const digitalTwinId = `digitalTwin-${v4()}`;
    
      const temporaryComponent = {
        "@id": componentId,
        "@type": "Interface",
        "@context": "dtmi:dtdl:context;2",
        displayName: "Component1",
        contents: [
          {
            "@type": "Property",
            name: "ComponentProp1",
            schema: "string"
          }
        ]
      };
    
      const temporaryModel = {
        "@id": modelId,
        "@type": "Interface",
        "@context": "dtmi:dtdl:context;2",
        displayName: "TempModel",
        contents: [
          {
            "@type": "Property",
            name: "Prop1",
            schema: "double"
          },
          {
            "@type": "Component",
            name: "Component1",
            schema: componentId
          }
        ]
      };
    
      const temporaryTwin = {
        $dtId: digitalTwinId,
        $metadata: {
          $model: modelId
        },
        Prop1: 42,
        Component1: {
          $metadata: {},
          ComponentProp1: "value1"
        }
      };
    
      // AZURE_DIGITALTWINS_URL: The URL to your Azure Digital Twins instance
      const url = 'https://ParADIM-ADT-Dev.api.wcus.digitaltwins.azure.net';
      if (url === undefined) {
        throw new Error("Required environment variable AZURE_DIGITALTWINS_URL is not set.");
      }
    
      // DefaultAzureCredential is provided by @azure/identity. It supports
      // different authentication mechanisms and determines the appropriate
      // credential type based of the environment it is executing in. See
      // https://www.npmjs.com/package/@azure/identity for more information on
      // authenticating with DefaultAzureCredential or other implementations of
      // TokenCredential.
      const credential = new DefaultAzureCredential();
      const serviceClient = new DigitalTwinsClient(url, credential);
    
      // Create models
      const newModels = [temporaryComponent, temporaryModel];
      const models = await serviceClient.createModels(newModels);
      //console.log(`Created Models:`);
      //console.log(inspect(models));
      
    }
    
    main().catch((err) => {
      console.log("error code: ", err.code);
      console.log("error message: ", err.message);
      console.log("error stack: ", err.stack);
    });

这是我得到的错误：

C:\Program Files\nodejs\node.exe .\index.js
error code:  undefined
error message:  Unexpected end of JSON input
error stack:  Error: Unexpected end of JSON input
    at AzureCliCredential.getToken (c:\ADTProject\node_modules\@azure\identity\dist\index.js:1529:27)
    at processTicksAndRejections (internal/process/task_queues.js:95:5)
    at async DefaultAzureCredential.getToken (c:\ADTProject\node_modules\@azure\identity\dist\index.js:1358:25)

因此，JSON 输入意外结束。这个错误来自@azure\identity\dist\index.js哪个是azure\identity包的一部分，所以不是我写的代码。我使用的代码来自教程，并且 JSON 是兼容的。getToken似乎执行该功能时出错。

任何帮助表示赞赏！我在这个问题上碰壁了！

标签： javascriptazureadt

解决方案

从文档中提取代码时，查看错误跟踪它无法从指定凭据检索令牌，这可能是我们如何传递它的问题。下面是我们通常在 JavaScript 中的连接方式：

const client = new SecretClient(keyVaultUrl, new DefaultAzureCredential());

下面是与 Cosmos 和存储通信的示例代码：

import { SecretClient } from '@azure/keyvault-secrets';
import { DefaultAzureCredential } from '@azure/identity';
import { CosmosClient } from '@azure/cosmos';

const keyVaultUrl = process.env('APP_KEY_VAULT_URI');
const credential = new DefaultAzureCredential();
let storageClient;
let cosmosClient;

async function configureClients() {
    const kvClient = new SecretClient(keyVaultUrl, credential);
    const storageUri = await client.getSecret('storageUri');
    const cosmosDbConnectionString = await client.getSecret('cosmosDb');

    cosmosClient = new CosmosClient(cosmosDbConnectonString);
    storageClient = new BlobServiceClient(storageUri, credential);
}

有关环境变量、设置 keyvault 的更多信息，请参阅 azure sdk博客以了解身份验证

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