Centralized Configuration Management using Azure App Configuration: Setting Up Offline Caching

using Azure.Identity;
using Microsoft.Extensions.Configuration.AzureAppConfiguration;

namespace MusicStore.Web
{
  public class Program
  {
    ..

    public static IHostBuilder CreateHostBuilder(string[] args) =>
      Host.CreateDefaultBuilder(args)
        .ConfigureWebHostDefaults(webBuilder => {
          webBuilder.UseStartup<Startup>();
        })
        .ConfigureAppConfiguration((context, config) => {
          var settings = config.Build();
          var appConfigEndpoint = settings["AppSettings:AppConfiguration:Endpoint"];
          var userAssignedIdentityClientId = settings["AppSettings:Identity:ClientId"];

          if (!string.IsNullOrEmpty(appConfigEndpoint))
          {
            var endpoint = new Uri(appConfigEndpoint);

            config.AddAzureAppConfiguration(options =>
            {
              options
                // Use managed identity to access app configuration
                .Connect(endpoint, new ManagedIdentityCredential(clientId: userAssignedIdentityClientId))

                // Setup dynamic refresh
                .ConfigureRefresh(refreshOpt =>
                {
                    refreshOpt.Register(key: "AppSettings:Version", refreshAll: true, label: LabelFilter.Null);
                    refreshOpt.SetCacheExpiration(TimeSpan.FromSeconds(10));
                })

                // Setup offline cache
                .SetOfflineCache(new OfflineFileCache())
                .UseFeatureFlags();
            });
          }
        });
  }
}