Visual Studio本地运行时ManagedIdentityCredential认证失败求助

近期配置了Azure App Service与Azure SQL Server使用托管身份访问，App Service已配置系统分配托管身份，并拥有SQL数据库的Owner角色，发布至App Service后可正常访问数据库。但在Visual Studio本地运行应用时，无法连接数据库：我的Azure账号已设为SQL Server的Azure Active Directory管理员，且登录后可通过Azure Data Studio连接并执行查询；我在VS中使用同一账号，甚至重新关联了Azure服务认证账号，却仍报错ManagedIdentityCredential authentication unavailable. Multiple attempts failed to obtain a token from the managed identity endpoint.。我未手动获取访问令牌，依赖Microsoft SQLClient通过连接字符串自动处理。

完整错误堆栈信息 #

at Microsoft.Data.ProviderBase.DbConnectionPool.CheckPoolBlockingPeriod(Exception e)
   at Microsoft.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
   at Microsoft.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
   at Microsoft.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   at Microsoft.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   at Microsoft.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection)
   at Microsoft.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   at Microsoft.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry, SqlConnectionOverrides overrides)
   at Microsoft.Data.SqlClient.SqlConnection.Open(SqlConnectionOverrides overrides)
   at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenInternal(Boolean errorsExpected)
   at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.Open(Boolean errorsExpected)
   at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReader(RelationalCommandParameterObject parameterObject)
   at Microsoft.EntityFrameworkCore.Query.Internal.SplitQueryingEnumerable`1.Enumerator.InitializeReader(Enumerator enumerator)
   at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.Execute[TState,TResult](TState state, Func`3 operation, Func`3 verifySucceeded)
   at Microsoft.EntityFrameworkCore.Query.Internal.SplitQueryingEnumerable`1.Enumerator.MoveNext()
   at System.Linq.Enumerable.TryGetSingle[TSource](IEnumerable`1 source, Boolean& found)
   at System.Linq.Queryable.FirstOrDefault[TSource](IQueryable`1 source, Expression`1 predicate)

Azure.RequestFailedException: A socket operation was attempted to an unreachable network. (169.254.169.254:80)
 ---> System.Net.Http.HttpRequestException: A socket operation was attempted to an unreachable network. (169.254.169.254:80)
 ---> System.Net.Sockets.SocketException (10051): A socket operation was attempted to an unreachable network.
   at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.ThrowException(SocketError error, CancellationToken cancellationToken)
   at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.System.Threading.Tasks.Sources.IValueTaskSource.GetResult(Int16 token)
   at System.Net.Sockets.Socket.<ConnectAsync>g__WaitForConnectWithCancellation|277_0(AwaitableSocketAsyncEventArgs saea, ValueTask connectTask, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.ConnectToTcpHostAsync(String host, Int32 port, HttpRequestMessage initialRequest, Boolean async, CancellationToken cancellationToken)
   --- End of inner exception stack trace ---
   at System.Net.Http.HttpConnectionPool.ConnectToTcpHostAsync(String host, Int32 port, HttpRequestMessage initialRequest, Boolean async, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.ConnectAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.CreateHttp11ConnectionAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.AddHttp11ConnectionAsync(HttpRequestMessage request)
   at System.Threading.Tasks.TaskCompletionSourceWithCancellation`1.WaitWithCancellationAsync(CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.GetHttp11ConnectionAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.SendWithVersionDetectionAndRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken)
   at System.Net.Http.DiagnosticsHandler.SendAsyncCore(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
   at System.Net.Http.HttpClient.<SendAsync>g__Core|83_0(HttpRequestMessage request, HttpCompletionOption completionOption, CancellationTokenSource cts, Boolean disposeCts, CancellationTokenSource pendingRequestsCts, CancellationToken originalCancellationToken)
   at Azure.Core.Pipeline.HttpClientTransport.ProcessAsync(HttpMessage message, Boolean async)
   --- End of inner exception stack trace ---
   at Azure.Core.Pipeline.HttpClientTransport.ProcessAsync(HttpMessage message, Boolean async)
   at Azure.Core.Pipeline.HttpPipelineTransportPolicy.ProcessAsync(HttpMessage message, ReadOnlyMemory`1 pipeline)
   at Azure.Core.Pipeline.RequestActivityPolicy.ProcessAsync(HttpMessage message, ReadOnlyMemory`1 pipeline, Boolean async)
   at Azure.Core.Pipeline.ResponseBodyPolicy.ProcessAsync(HttpMessage message, ReadOnlyMemory`1 pipeline, Boolean async)
   at Azure.Core.Pipeline.RedirectPolicy.ProcessAsync(HttpMessage message, ReadOnlyMemory`1 pipeline, Boolean async)
   at Azure.Core.Pipeline.RetryPolicy.ProcessAsync(HttpMessage message, ReadOnlyMemory`1 pipeline, Boolean async)

   at Azure.Identity.ImdsManagedIdentitySource.<AuthenticateAsync>d__15.MoveNext()
   at Azure.Identity.ManagedIdentityClient.<AuthenticateCoreAsync>d__17.MoveNext()
   at Azure.Identity.ManagedIdentityClient.<AppTokenProviderImpl>d__18.MoveNext()
   at Microsoft.Identity.Client.Internal.Requests.ClientCredentialRequest.<SendTokenRequestToProviderAsync>d__4.MoveNext()
   at Microsoft.Identity.Client.Internal.Requests.ClientCredentialRequest.<FetchNewAccessTokenAsync>d__3.MoveNext()
   at Microsoft.Identity.Client.Internal.Requests.ClientCredentialRequest.<ExecuteAsync>d__2.MoveNext()
   at Microsoft.Identity.Client.Internal.Requests.RequestBase.<RunAsync>d__12.MoveNext()
   at Microsoft.Identity.Client.ApiConfig.Executors.ConfidentialClientExecutor.<ExecuteAsync>d__3.MoveNext()
   at Azure.Identity.AbstractAcquireTokenParameterBuilderExtensions.<ExecuteAsync>d__0`1.MoveNext()
   at Azure.Identity.MsalConfidentialClient.<AcquireTokenForClientCoreAsync>d__21.MoveNext()
   at Azure.Identity.MsalConfidentialClient.<AcquireTokenForClientAsync>d__20.MoveNext()
   at Azure.Identity.ManagedIdentityClient.<AuthenticateAsync>d__16.MoveNext()
   at Azure.Identity.ManagedIdentityCredential.<GetTokenImplAsync>d__16.MoveNext()
   at 


Azure.Identity.CredentialDiagnosticScope.FailWrapAndThrow(Exception ex, String additionalMessage)
   at Azure.Identity.ManagedIdentityCredential.<GetTokenImplAsync>d__16.MoveNext()
   at Azure.Identity.ManagedIdentityCredential.<GetTokenAsync>d__14.MoveNext()
   at Microsoft.Data.SqlClient.ActiveDirectoryAuthenticationProvider.<AcquireTokenAsync>d__17.MoveNext()
   at Microsoft.Data.SqlClient.SqlInternalConnectionTds.<>c__DisplayClass147_1.<<GetFedAuthToken>b__1>d.MoveNext()
   at Microsoft.Data.SqlClient.SqlInternalConnectionTds.GetFedAuthToken(SqlFedAuthInfo fedAuthInfo)

DbContext代码（使用Microsoft.EntityFrameworkCore 7.0.3） #

public class DbEntities: DbContext
{
    public DbEntities() : base() { }
    //All DbSet<...> classes here
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseSqlServer(Environment.GetEnvironmentVariable("DB_CONNECTION_STRING"));
    }
}

AppSettings JSON配置 #

{
  "ConnectionStrings": {
    "DB_CONNECTION_STRING": "Server=tcp:MY-SERVER.database.windows.net;Initial Catalog=development;Persist Security Info=False;MultipleActiveResultSets=False;Encrypt=True;TrustServerCertificate=False;Authentication=\"Active Directory Managed Identity\";"
  },
}

内容的提问来源于stack exchange，提问作者Dillon Drobena