Revert "Handle exceptions thrown during Key Vault reference resolution during startup (#518)"

This reverts commit 6ce60b9.

Author: amerjusupovic

src/Microsoft.Extensions.Configuration.AzureAppConfiguration/AzureAppConfigurationProvider.cs

@@ -670,17 +670,6 @@ private async Task<bool> TryInitializeAsync(IEnumerable<ConfigurationClient> cli
 
                 throw;
             }
-            catch (KeyVaultReferenceException exception)
-            {
-                if (IsFailOverable(exception))
-                {
-                    startupExceptions.Add(exception);
-
-                    return false;
-                }
-
-                throw;
-            }
             catch (AggregateException exception)
             {
                 if (exception.InnerExceptions?.Any(e => e is OperationCanceledException) ?? false)
@@ -1031,15 +1020,6 @@ private async Task<T> ExecuteWithFailOverPolicyAsync<T>(
                         throw;
                     }
                 }
-                catch (KeyVaultReferenceException kvre)
-                {
-                    if (!IsFailOverable(kvre) || !clientEnumerator.MoveNext())
-                    {
-                        backoffAllClients = true;
-
-                        throw;
-                    }
-                }
                 catch (AggregateException ae)
                 {
                     if (!IsFailOverable(ae) || !clientEnumerator.MoveNext())
@@ -1128,20 +1108,6 @@ innerException is SocketException ||
                    innerException is IOException;
         }
 
-        private bool IsFailOverable(KeyVaultReferenceException kvre)
-        {
-            if (kvre.InnerException is RequestFailedException rfe && IsFailOverable(rfe))
-            {
-                return true;
-            }
-            else if (kvre.InnerException is AggregateException ae && IsFailOverable(ae))
-            {
-                return true;
-            }
-
-            return false;
-        }
-
         private async Task<Dictionary<string, ConfigurationSetting>> MapConfigurationSettings(Dictionary<string, ConfigurationSetting> data)
         {
             Dictionary<string, ConfigurationSetting> mappedData = new Dictionary<string, ConfigurationSetting>(StringComparer.OrdinalIgnoreCase);

tests/Tests.AzureAppConfiguration/FailoverTests.cs

@@ -332,55 +332,5 @@ public void FailOverTests_GetNoDynamicClient()
             // Only contains the client that passed while constructing the ConfigurationClientManager
             Assert.Single(clients);
         }
-
-        [Fact]
-        public void FailOverTests_FailOverOnKeyVaultReferenceException()
-        {
-            // Arrange
-            IConfigurationRefresher refresher = null;
-            var mockResponse = new Mock<Response>();
-
-            var mockClient1 = new Mock<ConfigurationClient>();
-            mockClient1.Setup(c => c.GetConfigurationSettingsAsync(It.IsAny<SettingSelector>(), It.IsAny<CancellationToken>()))
-                       .Throws(new KeyVaultReferenceException("Key vault reference failed.", new RequestFailedException(503, "Request failed.")));
-            mockClient1.Setup(c => c.GetConfigurationSettingAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
-                       .Throws(new KeyVaultReferenceException("Key vault reference failed.", new RequestFailedException(503, "Request failed.")));
-            mockClient1.Setup(c => c.GetConfigurationSettingAsync(It.IsAny<ConfigurationSetting>(), It.IsAny<bool>(), It.IsAny<CancellationToken>()))
-                       .Throws(new KeyVaultReferenceException("Key vault reference failed.", new RequestFailedException(503, "Request failed.")));
-            mockClient1.Setup(c => c.Equals(mockClient1)).Returns(true);
-
-            var mockClient2 = new Mock<ConfigurationClient>();
-            mockClient2.Setup(c => c.GetConfigurationSettingsAsync(It.IsAny<SettingSelector>(), It.IsAny<CancellationToken>()))
-                       .Returns(new MockAsyncPageable(Enumerable.Empty<ConfigurationSetting>().ToList()));
-            mockClient2.Setup(c => c.GetConfigurationSettingAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
-                       .Returns(Task.FromResult(Response.FromValue<ConfigurationSetting>(kv, mockResponse.Object)));
-            mockClient2.Setup(c => c.GetConfigurationSettingAsync(It.IsAny<ConfigurationSetting>(), It.IsAny<bool>(), It.IsAny<CancellationToken>()))
-                       .Returns(Task.FromResult(Response.FromValue<ConfigurationSetting>(kv, mockResponse.Object)));
-            mockClient2.Setup(c => c.Equals(mockClient2)).Returns(true);
-
-            ConfigurationClientWrapper cw1 = new ConfigurationClientWrapper(TestHelpers.PrimaryConfigStoreEndpoint, mockClient1.Object);
-            ConfigurationClientWrapper cw2 = new ConfigurationClientWrapper(TestHelpers.SecondaryConfigStoreEndpoint, mockClient2.Object);
-
-            var clientList = new List<ConfigurationClientWrapper>() { cw1, cw2 };
-            var configClientManager = new ConfigurationClientManager(clientList);
-
-            var config = new ConfigurationBuilder()
-                .AddAzureAppConfiguration(options =>
-                {
-                    options.ClientManager = configClientManager;
-                    options.Select("TestKey*");
-                    options.ConfigureRefresh(refreshOptions =>
-                    {
-                        refreshOptions.Register("TestKey1", "label")
-                            .SetCacheExpiration(TimeSpan.FromSeconds(1));
-                    });
-
-                    refresher = options.GetRefresher();
-                })
-                .Build();
-
-            // The build should be successful since one client was backed off and it failed over to the second client.
-            Assert.Equal("TestValue1", config["TestKey1"]);
-        }
     }
 }