如何為 ASP.NET Core 3.1 配置 Azure App Service 應用程序設置？

Question

此 ASP.NET Core 3.1 應用程序在本地計算機上運行良好，但在 Azure App Service 中托管時，它不使用“應用程序設置”下設置的配置變量。

以下變量已在 App Service 配置中創建，其值與appsettings.json中設置的值相同：

• 搜索服務名稱
• SearchServiceQueryApiKey

下面的controller file方法如何改成本地使用appsettings.json文件，雲端的Azure App服務配置設置？ appsettings.json未包含在構建並部署到 Azure 應用服務的 Azure DevOps 存儲庫中。

控制器文件方法：

私有無效 InitSearch()

{
    // Create a configuration using the appsettings file.
    _builder = new ConfigurationBuilder().AddJsonFile("appsettings.json");
    _configuration = _builder.Build();

    // Pull the values from the appsettings.json file.
    string searchServiceName = _configuration["SearchServiceName"];
    string queryApiKey = _configuration["SearchServiceQueryApiKey"];

    // Create a service and index client.
    _serviceClient = new SearchServiceClient(searchServiceName, new SearchCredentials(queryApiKey));
    _indexClient = _serviceClient.Indexes.GetClient("example-index");
}

應用設置.json

{
  "SearchServiceName": "example-search-service",
  "SearchServiceQueryApiKey": "example-query-api-key",
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },
  "AllowedHosts": "*"
}

Answer 1

Azure 應用服務中設置的配置設置使用環境變量提供給應用本身。 考慮到這一點，您只需將環境變量提供程序添加到您的ConfigurationBuilder ，如下所示：

_builder = new ConfigurationBuilder()
    .AddJsonFile("appsettings.json")
    .AddEnvironmentVariables();

有關詳細信息，請參閱使用 Azure 門戶覆蓋應用程序配置。

Answer 2

這奏效了。 必須使用依賴注入模式將“IWebHostEnvironment”引入控制器類。

public class MyController : Controller
{
    private readonly IWebHostEnvironment _environment;

    public MyController(IWebHostEnvironment env)
    {
        this._environment = env;
    }

    private void InitSearch(IWebHostEnvironment env)
    {
        // Create a configuration using the appsettings file.
        _builder = new ConfigurationBuilder()
            .SetBasePath(env.ContentRootPath)
            .AddJsonFile("appsettings.json", optional: true)
            .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
            .AddEnvironmentVariables();

        _configuration = _builder.Build();

        // Pull the values from the appsettings.json file.
        string searchServiceName = _configuration["SearchServiceName"];
        string queryApiKey = _configuration["SearchServiceQueryApiKey"];

        // Create a service and index client.
        _serviceClient = new SearchServiceClient(searchServiceName, new SearchCredentials(queryApiKey));
        _indexClient = _serviceClient.Indexes.GetClient("example-index");
    }
}