.Net Core 3.1 - Set ForContext for Serilog with Microsoft Ilogger interface

Question

How to dynamically set ForContext property for Serilog logger using Ilogger interface from Microsoft.Extensions.Logging?

Here's the code:

private readonly ILogger<UserService> _logger;

//DI code here

....

//inside some method
_logger.ForContext("CorrelationId", correlationId); // Ilogger doesn't contain ForContext extension method 

_logger.LogInformation("message");

I don't really want to use Ilogger interface from the Serilog as I don't want it to be serilog specific and it's not generic

Answer 1

ForContext with Microsoft.Extension.Logging

Microsoft ILogger interface does not have the ForContext property, however, according to several readings I could find on the topic the proper way to pass additional context information this interface is to use it's BeginScope method to pass a dictionary of values and then call your Logging method.

using (logger.BeginScope(new Dictionary<string, object> {{ "ParameterName", 999 }}))
{
    logger.LogInformation("This log entry and any other ones wrapped within this using statement will have context added similar to .ForContext with Serilog");
}

Using an extension method on ILogger

I found myself preferring to write an extension method for this purpose to avoid having using{} statements everywhere and make the intention more clear in my code when I want to add context information to my structured logging:

        public static void LogWithContext(this ILogger logger, Action LogAction, params KeyValuePair<string,object>[] contextDataParam)
        {
            Dictionary<string, object> contextData = new Dictionary<string, object>();
            foreach (KeyValuePair<string,object> kvp in contextDataParam)
            {
                contextData.TryAdd(kvp.Key, kvp.Value);
            }

            using (logger.BeginScope(contextData))
            {
                LogAction.Invoke();
            };

        }

And this can be called like this:

logger.LogWithContext(
    () => logger.LogError("Error with {Database}",_options.database),
        new KeyValuePair<string, object>("CallingFunction", nameof(thisFunction)),
       new KeyValuePair<string, object>("UserErrorType", "DB")