从 Azure 应用程序配置动态更新 .net 核心配置

Question

我想做什么： 我正在尝试使用 .net core 2.1 mvc web 应用程序在 Azure 应用程序配置中设置 Azure 应用程序配置，目标是能够在 azure 中更改密钥，并且 none 的密钥将更新我的应用程序，直到哨兵值发生变化。理论上，这应该允许我安全地热交换配置。

我的问题是： 当我这样做时，没有 WatchAndReloadAll() 方法可用于监视 IWebHostBuilder 上的哨兵，并且替代的 Refresh() 方法似乎不会像它们声明的那样刷新配置。

背景信息，以及我的尝试： 上周我参加了 VS Live - 圣地亚哥，并观看了有关 Azure App Configuration 的演示。在实现应用程序时，我在尝试让应用程序刷新配置值时遇到了一些问题，因此我还引用了这个 demo 来描述如何执行此操作。相关部分大约在 10 分钟内。但是，该方法似乎在 IWebHostBuilder 上不可用。

我正在引用的文档： 在官方文档中没有提及此方法，请参阅 doc quickstart .net core and doc dynamic configuration .net core

我的环境： 使用来自 Visual Studio Enterprise 2019 的运行的 dot net core 2.1，以及 Microsoft.Azure.AppConfiguration.AspNetCore 2.0.0-preview-010060003-1250

的最新预览 nuget 包

我的代码： 在演示中，他们通过 CreateWebHostBuilder(string[] args) 方法创建了一个 IWebHostBuilder，如下所示：

public static IWebHostBuilder CreateWebHostBuilder(string[] args)
{
    return WebHost.CreateDefaultBuilder(args)
    .ConfigureAppConfiguration((hostingContext, config) =>
    {
        var settings = config.Build();
        config.AddAzureAppConfiguration(options =>
        {
            options.Connect(settings["ConnectionStrings:AzureConfiguration"])
            .Use(keyFilter: "TestApp:*")
            .WatchAndReloadAll(key: "TestApp:Sentinel", pollInterval: TimeSpan.FromSeconds(5));
        }); 
    })
    .UseStartup<Startup>();
}

我也试过这种方法，使用当前的文档：

public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
    WebHost.CreateDefaultBuilder(args)
    .ConfigureAppConfiguration((hostingContext, config) =>
    {
        var settings = config.Build();

        config.AddAzureAppConfiguration(options =>
        {
            // fetch connection string from local config. Could use KeyVault, or Secrets as well.
            options.Connect(settings["ConnectionStrings:AzureConfiguration"])
            // filter configs so we are only searching against configs that meet this pattern
            .Use(keyFilter: "WebApp:*")
            .ConfigureRefresh(refreshOptions =>
            { 
                // In theory, when this value changes, on the next refresh operation, the config will update all modified configs since it was last refreshed.
                refreshOptions.Register("WebApp:Sentinel", true);
                refreshOptions.Register("WebApp:Settings:BackgroundColor", false);
                refreshOptions.Register("WebApp:Settings:FontColor", false);
                refreshOptions.Register("WebApp:Settings:FontSize", false);
                refreshOptions.Register("WebApp:Settings:Message", false);
            });
        });
    })
    .UseStartup<Startup>();

然后，在我的启动中class:

public Startup(IConfiguration configuration)
{
    Configuration = configuration;
}

public IConfiguration Configuration { get; }

// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
    services.Configure<Settings>(Configuration.GetSection("WebApp:Settings"));
    services.Configure<CookiePolicyOptions>(options =>
    {
        // This lambda determines whether user consent for non-essential cookies is needed for a given request.
        options.CheckConsentNeeded = context => true;
        options.MinimumSameSitePolicy = SameSiteMode.None;
    });

    services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
}

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    if (env.IsDevelopment())
    {
        app.UseDeveloperExceptionPage();
    }
    else
    {
        app.UseExceptionHandler("/Home/Error");
        app.UseHsts();
    }

    app.UseAzureAppConfiguration();
    app.UseHttpsRedirection();
    app.UseStaticFiles();
    app.UseCookiePolicy();

    app.UseMvc(routes =>
    {
        routes.MapRoute(
            name: "default",
            template: "{controller=Home}/{action=Index}/{id?}");
    });
}

最后是我的设置配置模型：

public class Settings
{
    public string BackgroundColor { get; set; }
    public long FontSize { get; set; }
    public string FontColor { get; set; }
    public string Message { get; set; }
}

现在，在我的控制器中，我提取这些设置并将它们放入视图包中以显示在视图上。

public class HomeController : Controller
{
    private readonly Settings _Settings;

    public HomeController(IOptionsSnapshot<Settings> settings)
    {
        _Settings = settings.Value;
    }

    public IActionResult Index()
    {
        ViewData["BackgroundColor"] = _Settings.BackgroundColor;
        ViewData["FontSize"] = _Settings.FontSize;
        ViewData["FontColor"] = _Settings.FontColor;
        ViewData["Message"] = _Settings.Message;

        return View();
    }
}

显示更改的简单视图：

<!DOCTYPE html>
<html lang="en">
<style>
    body {
        background-color: @ViewData["BackgroundColor"]
    }
    h1 {
        color: @ViewData["FontColor"];
        font-size: @ViewData["FontSize"];
    }
</style>
<head>
    <title>Index View</title>
</head>
<body>
    <h1>@ViewData["Message"]</h1>
</body>
</html>

我可以让它在第一时间拉下配置，但是，刷新功能似乎没有任何作用。

在最后一个示例中，我希望配置在哨兵被设置为任何新值时更新，或者至少在值更改 30 秒后更新。没有等待时间更新值，只有完全关闭并重新启动应用程序才能加载新配置。

更新： 添加 app.UseAzureAppConfiguration()；在启动时的配置方法中，并在缓存上设置显式超时以固定刷新方法在固定时间后刷新，但哨兵功能仍然不起作用，刷新方法上的 updateAll 标志也不起作用。

Answer 1

好的，经过多次测试和反复试验，我成功了。

我的问题是 Azure 的配置方法缺少服务。这里有一些有趣的行为，因为它仍然会下拉设置，只是不会更新，如果它丢失了。因此，一旦将其放入，并且根据文档配置了适当的哨兵，它就可以与 updateAll 标志一起使用。但是，目前没有记录。

解决方法如下：

在Program.cs中：

using Microsoft.AspNetCore;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration.AzureAppConfiguration;

namespace ASPNetCoreApp
{
    public class Program
    {
        public static void Main(string[] args)
        {
            CreateWebHostBuilder(args).Build().Run();
        }   // Main

        public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
            WebHost.CreateDefaultBuilder(args)
            .ConfigureAppConfiguration((hostingContext, config) =>
            {
                var settings = config.Build();

                config.AddAzureAppConfiguration(options =>
                {
                    // fetch connection string from local config. Could use KeyVault, or Secrets as well.
                    options.Connect(settings["ConnectionStrings:AzureConfiguration"])
                    // filter configs so we are only searching against configs that meet this pattern
                    .Use(keyFilter: "WebApp:*")
                    .ConfigureRefresh(refreshOptions =>
                    { 
                        // When this value changes, on the next refresh operation, the config will update all modified configs since it was last refreshed.
                        refreshOptions.Register("WebApp:Sentinel", true);
                        // Set a timeout for the cache so that it will poll the azure config every X timespan.
                        refreshOptions.SetCacheExpiration(cacheExpirationTime: new System.TimeSpan(0, 0, 0, 15, 0));
                    });
                });
            })
            .UseStartup<Startup>();
    }
}

然后在 Startup.cs:

using ASPNetCoreApp.Models;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

namespace ASPNetCoreApp
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            // bind the config to our DI container for the settings we are pulling down from azure.
            services.Configure<Settings>(Configuration.GetSection("WebApp:Settings"));
            services.Configure<CookiePolicyOptions>(options =>
            {
                // This lambda determines whether user consent for non-essential cookies is needed for a given request.
                options.CheckConsentNeeded = context => true;
                options.MinimumSameSitePolicy = SameSiteMode.None;
            });

            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            {
                app.UseExceptionHandler("/Home/Error");
                app.UseHsts();
            }
            // Set the Azure middleware to handle configuration
            // It will pull the config down without this, but will not refresh.
            app.UseAzureAppConfiguration();
            app.UseHttpsRedirection();
            app.UseStaticFiles();
            app.UseCookiePolicy();

            app.UseMvc(routes =>
            {
                routes.MapRoute(
                    name: "default",
                    template: "{controller=Home}/{action=Index}/{id?}");
            });
        }
    }
}

我将我的 azure 检索数据绑定到的设置模型：

namespace ASPNetCoreApp.Models
{
    public class Settings
    {
        public string BackgroundColor { get; set; }
        public long FontSize { get; set; }
        public string FontColor { get; set; }
        public string Message { get; set; }
    }
}

将配置设置为 ViewBag 以传递到我们的视图的通用家庭控制器：

using ASPNetCoreApp.Models;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Options;
using System.Diagnostics;

namespace ASPNetCoreApp.Controllers
{
    public class HomeController : Controller
    {
        private readonly Settings _Settings;

        public HomeController(IOptionsSnapshot<Settings> settings)
        {
            _Settings = settings.Value;
        }
        public IActionResult Index()
        {
            ViewData["BackgroundColor"] = _Settings.BackgroundColor;
            ViewData["FontSize"] = _Settings.FontSize;
            ViewData["FontColor"] = _Settings.FontColor;
            ViewData["Message"] = _Settings.Message;

            return View();
        }

        public IActionResult About()
        {
            ViewData["Message"] = "Your application description page.";

            return View();
        }

        public IActionResult Contact()
        {
            ViewData["Message"] = "Your contact page.";

            return View();
        }

        public IActionResult Privacy()
        {
            return View();
        }

        [ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
        public IActionResult Error()
        {
            return View(new ErrorViewModel { RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier });
        }
    }
}

我们的观点：

<!DOCTYPE html>
<html lang="en">
<style>
    body {
        background-color: @ViewData["BackgroundColor"]
    }
    h1 {
        color: @ViewData["FontColor"];
        font-size: @ViewData["FontSize"];
    }
</style>
<head>
    <title>Index View</title>
</head>
<body>
    <h1>@ViewData["Message"]</h1>
</body>
</html>

希望这对其他人有帮助！

从 Azure 应用程序配置动态更新 .net 核心配置

Dynamically update .net core config from Azure App Configuration

c#

azure

azure-app-configuration