how to log custom messages to azure portal analytics monitoring logs

Question

I am trying to add custom logs in my c# asp dot net core web api. I am able to find the api calls logs in Azure portal -> application insights -> logs.

But i am not able to find the custom logs i am entering using below code. whats the place to search for them.

public async Task Invoke(HttpContext httpContext)
{
    // First, get the incoming request
    var request = await FormatRequest(httpContext.Request);

    // TODO: Save log to chosen datastore
    _logger.LogInformation('custommessage101');

    // ------
}

In log analytics query editor i used below query but it didnt fetch anything. Is it even the right place(Azure portal -> application insights -> logs) i am looking at ?

requests | search "custommessage101"

Answer 1

It may be that when you configured your logger you set the log level higher than information.

The following set the log level so that Information logging will be stored:

builder.AddFilter<Microsoft.Extensions.Logging.ApplicationInsights.ApplicationInsightsLoggerProvider>("", LogLevel.Information);

Answer 2

Messages logged to the ILogger interface end up as traces in application insights. An example query would be:

traces | where message == "custommessage101"

Another option would be the Search :

The default log level for messages to application insights is set to Warning . As Shiraz point out, you need to set it to informational. You can do that using code as shown by Shiraz or by adjusting the appsettings.json file:

{
  "Logging": {
    "LogLevel": {
      "Default": "Information"
    },
    "ApplicationInsights": {
      "LogLevel": {
        "Default": "Information"
      }
    }
  }
}