I have a Azure Function App running on .NET 6, I am using Microsoft.Extension.Logging for logging and everything is working perfectly.

Now I have a new requirement to support structured logging, so I decided to use Serilog, but even after doing all configurations, structured logs are not showing up in application insights as expected.

This is my startup.cs configuration for Serilog:

public override void Configure(IFunctionsHostBuilder builder)
{
    var telemetryConfiguration = TelemetryConfiguration.CreateDefault();
    telemetryConfiguration.ConnectionString = Settings.ApplicationInsightsConnectionString;

    // Create and initialize the dependency tracking module
    var dependencyModule = new DependencyTrackingTelemetryModule();
    dependencyModule.Initialize(telemetryConfiguration);

    // Create the custom telemetry processor
    var telemetryProcessorChainBuilder = telemetryConfiguration.DefaultTelemetrySink.TelemetryProcessorChainBuilder;
    var configuration = builder.Services.BuildServiceProvider().GetService<IConfiguration>();

    telemetryProcessorChainBuilder.Use(next => new CustomTelemetryProcessor(next, configuration));

    // Build the telemetry processor chain
    telemetryProcessorChainBuilder.Build();

    Log.Logger = new LoggerConfiguration()
                           .WriteTo.ApplicationInsights(telemetryConfiguration, TelemetryConverter.Traces)
                           .CreateLogger();

    builder.Services.AddSingleton(telemetryConfiguration);
    builder.Services.AddSingleton(typeof(IAppLogger<>), typeof(AppLogger<>));
  
    // rest of the code...
}

And this is the log I’m logging using AppLogger which uses Microsoft.Extension.Logging:

_logger.LogInformation("Log message {@LogMessage}", new LogMessage { ApplicationName = ApplicationDetails.ApplicationName, MethodName = AzureFunctionNames.Function1, IngressEvent = inputMessage.Payload.EventBody });

It’s logging in Application Insight as serialised JSON of LogMessage, instead of logging in structured log format so that I should be able to query on each entity of LogMessage class.

What could be the reason that I am not able to see structured logs in Application Insights?