Configure / Bind application with Azure Key Vault

As good development practice teams should not check-in any secrets/configuration setting like DB connection strings, usernames, passwords. Instead they should be be kept in safe stores like key vault and accessed directly from your application, without much ado/difficulty. 

 If you need to configure your application with Azure key vault for reading all your application configuration keys / settings, then do the following changes in your application and it would bind the appsettings.config with the keyvault of your settings/configuration. 

Here the following settings you need to do in your code : 

using Microsoft.AspNetCore.Hosting;
using Microsoft.Azure.KeyVault;
using Microsoft.Azure.Services.AppAuthentication;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Configuration.AzureKeyVault;
using Microsoft.Extensions.Hosting;

namespace Sample.Parag.KeyVaultExample.TestWF
{
    public class Program
    {
        public static void Main(string[] args)
        {
            CreateHostBuilder(args).Build().Run();
        }

        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
             .ConfigureAppConfiguration(async (builder) =>
             {
                 var builtConfig = builder.Build();
                 var keyVaultName = builtConfig["KeyVaultName"];
                 var azureServiceTokenProvider = new AzureServiceTokenProvider();
                 var keyVaultClient = new KeyVaultClient(new KeyVaultClient.AuthenticationCallback(azureServiceTokenProvider.KeyVaultTokenCallback));
                 builder.AddAzureKeyVault(
                   $"https://{keyVaultName}.vault.azure.net/", keyVaultClient, new DefaultKeyVaultSecretManager());
             })
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup<Startup>();
                });
    }
}

Here KeyVaultName in buildConfig["KeyVaultName"], is defined in appsettings.json , and it is the name of keyvault name. 

like 

...

"KeyVaultName": "azureApp-key-vaultName",

...

Next you can start accessing any secret stored in Azure Key Vault like this : 

        public string GetFooFunc()
        {
            return this.config["SomeKeyName"];
        }