[.NET 6] Implement custom LogProvider with RabbitMQ into ILogger

In .NET 6, ILogger is very easy to use, but on modern project, we will write log to somewhere else and use log viewer to read it. For example: sent log to RabbitMQ and read on Kibana

Here is a demo to show how to lmplement a custom logging provider with RabbitMQ into ILogger in .NET 6 RC1, basically same as this article but with some modify.

Step 0 : Before Start

In this demo we choose RabbitMQ.Client to communite with RabbitMQ, you can choose other client if you want, just install it from nuget, easy.

Another thing is RabbitMQ server, if you don't have one, you can use docker to create one.

docker run -it --rm --name rabbitmq -p 5672:5672 -p 15672:15672 rabbitmq:3.9-management

[.NET 6] System.StackOverflowException after upgrade VS2022 to Preview 4.1 from 3.1

After upgrade VS2022 to Preview 4.1 from 3.1, my project throw StackOverflowException (after fix lots of reference error)

System.StackOverflowException
  HResult=0x800703E9
  Message=Exception of type 'System.StackOverflowException' was thrown.

Stack overflow.
Repeat 2291 times:
--------------------------------
   at Microsoft.Extensions.Primitives.ChangeToken+ChangeTokenRegistration`1[[System.__Canon, System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].OnChangeTokenFired()
   at Microsoft.Extensions.Primitives.ChangeToken+ChangeTokenRegistration`1+<>c[[System.__Canon, System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].<RegisterChangeTokenCallback>b__7_0(System.Object)
   at System.Threading.CancellationTokenSource.Invoke(System.Delegate, System.Object, System.Threading.CancellationTokenSource)
   at System.Threading.CancellationTokenSource.Register(System.Delegate, System.Object, System.Threading.SynchronizationContext, System.Threading.ExecutionContext)
   at System.Threading.CancellationToken.Register(System.Delegate, System.Object, Boolean, Boolean)
   at System.Threading.CancellationToken.Register(System.Action`1<System.Object>, System.Object)
   at Microsoft.Extensions.Configuration.ConfigurationReloadToken.RegisterChangeCallback(System.Action`1<System.Object>, System.Object)
   at Microsoft.Extensions.Primitives.ChangeToken+ChangeTokenRegistration`1[[System.__Canon, System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].RegisterChangeTokenCallback(Microsoft.Extensions.Primitives.IChangeToken)
--------------------------------
   at Microsoft.Extensions.Primitives.ChangeToken+ChangeTokenRegistration`1[[System.__Canon, System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].OnChangeTokenFired()
   at Microsoft.Extensions.Primitives.ChangeToken+ChangeTokenRegistration`1+<>c[[System.__Canon, System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].<RegisterChangeTokenCallback>b__7_0(System.Object)
   at System.Threading.CancellationTokenSource.Invoke(System.Delegate, System.Object, System.Threading.CancellationTokenSource)
   at System.Threading.CancellationTokenSource+CallbackNode+<>c.<ExecuteCallback>b__9_0(System.Object)
   at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object)
   at System.Threading.CancellationTokenSource+CallbackNode.ExecuteCallback()
   at System.Threading.CancellationTokenSource.ExecuteCallbackHandlers(Boolean)
   at System.Threading.CancellationTokenSource.NotifyCancellation(Boolean)
   at System.Threading.CancellationTokenSource.Cancel()
   at Microsoft.Extensions.Configuration.ConfigurationManager.RaiseChanged()
   at Microsoft.Extensions.Configuration.ConfigurationManager.AddSource(Microsoft.Extensions.Configuration.IConfigurationSource)
   at Microsoft.Extensions.Configuration.ConfigurationManager.Microsoft.Extensions.Configuration.IConfigurationBuilder.Add(Microsoft.Extensions.Configuration.IConfigurationSource)
   at Microsoft.Extensions.Configuration.ChainedBuilderExtensions.AddConfiguration(Microsoft.Extensions.Configuration.IConfigurationBuilder, Microsoft.Extensions.Configuration.IConfiguration, Boolean)
   at Microsoft.Extensions.Configuration.ChainedBuilderExtensions.AddConfiguration(Microsoft.Extensions.Configuration.IConfigurationBuilder, Microsoft.Extensions.Configuration.IConfiguration)
   at Microsoft.AspNetCore.Builder.WebApplicationBuilder.Build()
   at Program.<Main>$(System.String[])

I know post to MS's developer forum is useless, and VS2022 can't downgrade now, so the only way is try and error by myself.

Turn out, the stackoverflow exception cause by Microsoft.Extensions.Configuration from this code:

builder.Services.AddSingleton<IConfiguration>(builder.Configuration);

After more dig-in, I found the framework already called this on Hosting , so maybe the duplicate call cause the stackoverflow exception, but still not sure why it worked on VS2022 preview 3.1, not work on preview 4.1.

Solution

Remove the line

services.AddSingleton<IConfiguration>(configuration);

(or similar) on your Program.cs

[JAVA] HMAC SHA384 example code

It was a bit hard to find correct HMAC SHA384 code for JAVA, so here to share my example code, hope can save some time to try and error.

import java.security.NoSuchAlgorithmException;
import javax.crypto.spec.SecretKeySpec;
import javax.crypto.Mac;

public class SecureUtils {

private static String bytesToHex(final byte[] hash) {
    final StringBuffer hexString = new StringBuffer();
    for (int i = 0; i < hash.length; i++) {
        final String hex = Integer.toHexString(0xff & hash[i]);
        if (hex.length() == 1) {
            hexString.append('0');
        }
        hexString.append(hex);
    }
    return hexString.toString();
}

public static void main(String[] args) throws NoSuchAlgorithmException {
    final String nonce = "test"; //your key
    final String message = "Password"; //your plain txt
    SecretKeySpec signingKey = new SecretKeySpec(nonce.getBytes(),"HmacSHA384");
    final Mac mac = Mac.getInstance("HmacSHA384");
    try{
        mac.init(signingKey);
        System.out.println(bytesToHex(mac.doFinal(message.getBytes())));
    }
        catch(Exception ex){    }
    }
}

You can test this example in here 

Check result with online hmac generator

Those code modify from stackoverflow HMAC SHA-384 in Java

[敗家] Alienware m17 R3

Alienware m17 R3

上一台筆電是2013年買的Alienware M14x R2，拿來寫code已經有點慢了，最近終於找了機會買了新筆電，17吋螢幕真的比較適用啊。

不能免俗地附上配備表。

順帶一提，這次順便買了外星人背包，裝17吋筆電剛好，還有些空間可以裝我需要的東西，相當不錯。

這是2020/12月底買的，沒想到一忙就忘記貼文，直到現在。