我要做什么： 我正在尝试使用.net核心2.1 mvc Web应用程序在Azure App Configuration中设置带有前哨键的Azure App Configuration，目的是能够以天蓝色的方式更改键，并且直到前哨值已更改。从理论上讲，这应该允许我安全地热交换配置。
我的问题是什么 当我这样做时，没有可用的WatchAndReloadAll（）方法来监视IWebHostBuilder上的哨兵，并且备用的Refresh（）方法似乎并未刷新状态。
背景信息以及我尝试过的操作： 上周，我参加了圣地亚哥的VS Live，并观看了有关Azure应用程序配置的演示。我在尝试使应用程序隐含配置值时遇到一些问题，因此我也参考了demo并描述了如何执行此操作。相关部分大约在10分钟后。但是，该方法在IWebHostBuilder上似乎不可用。
我参考的文档： 在官方文档中没有对此方法的引用，请参见doc quickstart .net core和doc dynamic configuration .net core
我的环境： 使用从Visual Studio Enterprise 2019运行的dot net core 2.1，以及适用于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>();
}
我也使用当前文档尝试过这种方式：
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，在我的启动课程中：
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，我将这些设置拉出并放入视图包中以在视图上显示。
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>
我可以通过它第一次拉下配置，但是刷新功能似乎没有任何作用。
在上一个示例中，我希望在哨兵设置为任何新值时更新配置，或者至少在更改后30秒更新值。无需等待太多时间即可更新值，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configure方法中，并在config的缓存上设置显式超时，以固定refresh方法在固定的时间后刷新，但是sendinel功能仍然不起作用，refresh方法上的updateAll标志也不起作用。
答案 0 :(得分：4)
好吧，经过大量的测试和反复试验，我可以正常工作。
我的问题是在configure方法上缺少天蓝色的服务。这里有一些有趣的行为，因为它仍然会下拉设置，如果丢失，它只会更新。因此，一旦将其放入并根据每个文档配置了适当的哨兵，它将与updateAll标志一起使用。但是，目前尚未记录。
这是解决方案：
在Program.cs中：
rm -rf `ls -d */`
然后在Startup.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>();
}
}
我要将我的天蓝色检索到的数据绑定到“设置”模型：
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?}");
});
}
}
}
一个通用家庭控制器，其配置被设置为ViewBag以传递到我们的视图中：
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; }
}
}
我们的观点：
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 });
}
}
}
希望这对其他人有帮助！