/health endpoint crashes with NotSupportedException on source-generated JSON serializer

[Aaronontheweb]

Description

The /health endpoint returns an anonymous type that is not registered in the source-generated JSON serializer context (SkillServer.Models.SkillServerJsonContext), causing every health check request to throw System.NotSupportedException.

Error

System.NotSupportedException: JsonTypeInfo metadata for type '<>f__AnonymousType13`2[System.String,System.DateTimeOffset]' was not provided by TypeInfoResolver of type '[Microsoft.AspNetCore.OpenApi.OpenApiJsonSchemaContext, SkillServer.Models.SkillServerJsonContext]'. 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.
   at System.Text.Json.ThrowHelper.ThrowNotSupportedException_NoMetadataForType(Type type, IJsonTypeInfoResolver resolver)
   at Microsoft.AspNetCore.Http.HttpResultsHelper.WriteResultAsJsonAsync[TValue](...)

Impact

• Kubernetes HTTP liveness/readiness probes targeting /health cause the pod to crash-loop
• Workaround: use tcpSocket probes instead of httpGet probes

Reproduction

curl http://skillserver:8080/health

Suggested Fix

Replace the anonymous type in the health endpoint response with a named type registered in SkillServerJsonContext, or add Results.Ok("Healthy") as a plain string response.

Environment

• Image: ghcr.io/netclaw-dev/skillserver:0.1.0
• Runtime: Kubernetes (MicroK8s 1.32)