Response body for request/response Logging

Question

I\'m trying to write a Owin midleware component that would LOG every incoming request and response to the database.

Here\'s how far I managed to get.

I got stu

Answer 1

I've solved the problem by applying an action attribute writing the request body to OWIN environment dictionary. After that, the logging middleware can access it by a key.

public class LogResponseBodyInterceptorAttribute : ActionFilterAttribute
{
    public override async Task OnActionExecutedAsync(HttpActionExecutedContext actionExecutedContext, CancellationToken cancellationToken)
    {
        if (actionExecutedContext?.Response?.Content is ObjectContent)
        {
            actionExecutedContext.Request.GetOwinContext().Environment["log-responseBody"] =
                await actionExecutedContext.Response.Content.ReadAsStringAsync();
        }
    }
}

And then in the middleware:

public class RequestLoggingMiddleware
{
    ...
    private void LogResponse(IOwinContext owinContext)
    {
        var message = new StringBuilder()
            .AppendLine($"{owinContext.Response.StatusCode}")
            .AppendLine(string.Join(Environment.NewLine, owinContext.Response.Headers.Select(x => $"{x.Key}: {string.Join("; ", x.Value)}")));

        if (owinContext.Environment.ContainsKey("log-responseBody"))
        {
            var responseBody = (string)owinContext.Environment["log-responseBody"];
            message.AppendLine()
                .AppendLine(responseBody);
        }

        var logEvent = new LogEventInfo
        {
            Level = LogLevel.Trace,
            Properties =
            {
                {"correlationId", owinContext.Environment["correlation-id"]},
                {"entryType", "Response"}
            },
            Message = message.ToString()
        };

        _logger.Log(logEvent);
    }
}