[Question] Elastic.CommonSchema.NLog and System.Text.Json with source generation

[markdsitu]

Hi, we are planning to use Elastic.CommonSchema.NLog package in our C# Lambda which is performing logging using NLog already. The code package is produced with AOT compilation and we are using source generation for System.Text.Json for maximum AOT compatibility.

When I plugged EcsLayout into my console logs I started getting these errors.

JsonTypeInfo metadata for type 'System.DateTimeOffset' was not provided by TypeInfoResolver of type '<null>'. If using source generation, ensure that all root types passed to the serializer have been annotated with 'JsonSerializableAttribute', along with any types that might be serialized polymorphically.

With stack traces like this:

   at System.Text.Json.ThrowHelper.ThrowNotSupportedException_NoMetadataForType(Type type, IJsonTypeInfoResolver resolver)
   at System.Text.Json.JsonSerializerOptions.GetTypeInfoInternal(Type type, Boolean ensureConfigured, Nullable`1 ensureNotNull, Boolean resolveIfMutable, Boolean fallBackToNearestAncestorType)
   at System.Text.Json.JsonSerializerOptions.GetConverterInternal(Type typeToConvert)
   at Elastic.CommonSchema.Serialization.EcsJsonConfiguration..cctor() in C:\stash\ecs-dotnet\src\Elastic.CommonSchema\Serialization\JsonConfiguration.cs:line 39

I have a couple of questions.

1. Is there some configuration currently I can perform to make this work?
2. If not, could this be made to work in Elastic.CommonSchema.NLog?

I've pulled the ecs-dotnet repo and made local changes directly. I could get it to work with my use case with the following changes.

However I don't understand enough of how everything hangs together to know if this will work for all use-cases.

Appreciate your assistance.

[Mpdreamz]

Thank you for reporting this @markdsitu

We recently spent time making:

• https://github.com/elastic/elastic-ingest-dotnet
• https://github.com/elastic/elastic-transport-net

AOT compatible but until now could not find time to do the same for the ECS.NET libraries.

I opened #527 to ensure we utilize JsonSerializerContext everywhere including passing them down properly to the ingestion libraries.

I still need to follow up that PR with appropiate AOT msbuild properties and annotations.

[markdsitu]

Thanks for the update @Mpdreamz.

[Mpdreamz]

Hey @markdsitu we just released 8.19 and 9.0 which should address our AOT compatibility issues. We now have AOT tests which uncovered several other places we needed to address. #529

Note that you need a minimum of NLog 6 to get its AOT compatibility included too.

Hope this unblocks you!

[markdsitu]

Thanks heaps @Mpdreamz. I've pulled the updated package (v9 with NLog 6), and it now works expected from my prelim testing.