Question: how to connect to Azure MySQL / use SSL certificate

The question

I’m trying to connect to Azure MySQL. There SSL certificate is must-have. So that’s what I’m doing. Connection string looks like this: server=imgeneus-test.mysql.database.azure.com;userid=aosyatnik;pwd=password;port=3306;database=whatever;SSL Mode=Required;SslCA=BaltimoreCyberTrustRoot.crt.pem

BaltimoreCyberTrustRoot.crt.pem is located in the same project directory.

I get next exception, when called DbContext.Migrate():

System.InvalidOperationException: "The collection already contains item with same key 'net.transport''"
   at System.Diagnostics.ActivityTagsCollection.Add(String key, Object value)
   at MySqlConnector.Core.ServerSession.<OpenTcpSocketAsync>d__95.MoveNext()
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at MySqlConnector.Core.ServerSession.<ConnectAsync>d__79.MoveNext()
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult()
   at MySqlConnector.Core.ConnectionPool.<ConnectSessionAsync>d__21.MoveNext()
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Threading.Tasks.ValueTask`1.get_Result()
   at System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable`1.ConfiguredValueTaskAwaiter.GetResult()
   at MySqlConnector.Core.ConnectionPool.<GetSessionAsync>d__10.MoveNext()
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at MySqlConnector.Core.ConnectionPool.<GetSessionAsync>d__10.MoveNext()
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Threading.Tasks.ValueTask`1.get_Result()
   at System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable`1.ConfiguredValueTaskAwaiter.GetResult()
   at MySqlConnector.MySqlConnection.<CreateSessionAsync>d__126.MoveNext()
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Threading.Tasks.ValueTask`1.get_Result()
   at System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable`1.ConfiguredValueTaskAwaiter.GetResult()
   at MySqlConnector.MySqlConnection.<OpenAsync>d__27.MoveNext()
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at MySqlConnector.MySqlConnection.Open()
   at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenDbConnection(Boolean errorsExpected)
   at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenInternal(Boolean errorsExpected)
   at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.Open(Boolean errorsExpected)
   at Pomelo.EntityFrameworkCore.MySql.Storage.Internal.MySqlRelationalConnection.Open(Boolean errorsExpected)
   at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReader(RelationalCommandParameterObject parameterObject)
   at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.Enumerator.InitializeReader(Enumerator enumerator)
   at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.Enumerator.<>c.<MoveNext>b__19_0(DbContext _, Enumerator enumerator)
   at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.<>c__DisplayClass31_0`2.<Execute>b__0(DbContext context, TState state)
   at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.ExecuteImplementation[TState,TResult](Func`3 operation, Func`3 verifySucceeded, TState state)
   at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.Execute[TState,TResult](TState state, Func`3 operation, Func`3 verifySucceeded)
   at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.Enumerator.MoveNext()
   at System.Linq.Enumerable.TryGetSingle[TSource](IEnumerable`1 source, Boolean& found)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.Execute[TResult](Expression query)
   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.Execute[TResult](Expression expression)
   at System.Linq.Queryable.Count[TSource](IQueryable`1 source)
   at Imgeneus.Login.Pages.Index.GetNumberOfRegisteredUsers() in C:\Projects\Shaiya\Imgeneus\src\Imgeneus.Login\Pages\Index.razor:line 25

The same code works fine on localhost.

Further technical details

MySQL version: 8.0 Operating system: Win 10 Pomelo.EntityFrameworkCore.MySql version: 6.0.0 Microsoft.AspNetCore.App version: .NET 6.0

P.S. sorry, if it’s wrong repo to ask.

[aosyatnik]

There’s a similar issue in the underlying repo at mysql-net/MySqlConnector#1074 which offers a solution.

You should be able to work around it by adding ; TLS Version = TLS 1.1 to your connection string

However, the Azure documentation at Connect to Azure Database for MySQL - Flexible Server with encrypted connections mentions the following.

Azure Database for MySQL Flexible Server supports encrypted connections using Transport Layer Security (TLS 1.2) by default and all incoming connections with TLS 1.0 and TLS 1.1 will be denied by default.

So try adding TlsVersion=TLS 1.2 to your connection string. @bgrainger Any thoughts/suggestions?

Adding TlsVersion=TLS 1.2 fixed issue. Thank you very much!

[mguinness]

Try updating to Pomelo 6.0.1 which will bring in MySqlConnector 2.1.2 (instead of 2.0.0 currently). If that doesn’t work, you can manually add the latest MySqlConnector package in your csproj file.