azure - 我的 Azure Web 应用程序无法从正确的 appsetting.{env}.json 文件中读取参数

Question

我开发了一个 Azure Web 应用程序 (dotnetcore 3.1)，并为每个环境添加了 appsettings 文件，例如

• appsettings.json
• appsettings.Prod.json
• appsettings.Staging.json
• appsettings.Development.json

它按预期在我的本地工作，但当我将其部署到 Azure 门户时，它始终从 appsettings.json 文件中读取参数，即使我将 ASPNETCORE_ENVIRONMENT = Staging 添加到 azure 应用程序设置也是如此。在这种情况下，我希望它应该从 appsettings.Staging.json 文件中读取参数。

我会错过什么？知道可能出什么问题吗？提前致谢...

MVC Web 应用

Startup.cs

public void ConfigureServices(IServiceCollection services)
    {
        var envName = Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT", EnvironmentVariableTarget.Machine);
        IConfigurationBuilder cb = new ConfigurationBuilder()
            .SetBasePath(Directory.GetCurrentDirectory())
            .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
            .AddJsonFile($"appsettings.{envName}.json", optional: true, reloadOnChange: true)
            .AddEnvironmentVariables();
        
        IConfiguration cfg = cb.Build();

        services.AddControllersWithViews().AddRazorRuntimeCompilation();
        services.AddSingleton(cfg);
        services.AddMemoryCache();
        services.AddSession();
        services.AddMvc();
    }

HomeController.cs

public IActionResult Index()
{
    var key = _configuration["Settings:firstKey"].ToString();
    ViewBag.FirstKey = key;
    return View();
}

appsettings.json

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },
  "Settings": {
    "firstKey": "from appsettings.json"
  }
}

appsettings.Staging.json

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },
  "Settings": {
    "firstKey": "from appsettings.Staging.json"
  }
}

appsettings.Development.json

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },
  "Settings": {
    "firstKey": "from appsettings.Development.json"
  }
}

appsettings.Prod.json

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },
  "Settings": {
    "firstKey": "from appsettings.Prod.json"
  }
}

azure 应用程序设置

Answer 1

我通过更新program.cs和startup.cs文件解决了我的问题，如下所示。

Startup.cs

public void ConfigureServices(IServiceCollection services)
{
   // removed appsettings configuration in startup.cs file
   services.AddMemoryCache();
   services.AddSession();
   services.AddMvc();
   services.AddControllersWithViews();
}

Program.cs

public static IHostBuilder CreateHostBuilder(string[] args) =>
  Host.CreateDefaultBuilder(args)
    .ConfigureWebHostDefaults(webBuilder =>
    {
       webBuilder.UseStartup<Startup>()
       .ConfigureAppConfiguration((config)=> {
         var appSetting = $"appsettings.{Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT", EnvironmentVariableTarget.Machine)}.json";
         config.AddJsonFile(appSetting, optional: true, reloadOnChange: true);
       });
    });

我猜 Web 应用程序在部署到 Azure 门户时首先无法读取startup.cs 中的环境变量

结果