How can i get logs/debugging for an error 500? - asp.net

Question

I'm working on a .NET Core 2.0 web application. I got a mocked database where application works good. Today i created a clean database and got this error 500 both on IIS Express and on regular IIS.
The thing is: i couldn't debug why is throwing the error 500. The application just run.
I've currently tried:
Check IIS logs by activating stdoutLogEnabled="true" and the only log created was:
Hosting environment: Production Content root path:
C:\Users\pistolon\Downloads\peto Now listening on:
http://localhost:13361 Application started. Press Ctrl+C to shut down.
Debugging from start the startup.cs file.
When I switch back to the mocked db it works without error.
Do you any of you could point me on where could i get an exception or log for this?

Answer 1

You can use Event Viewer or Visual Studio Remote Debugging to debug your deployed applications.
Also, you can use a logging framework like Serilog and use one of it sinks like file sink and create a middleware which catches and logs your exceptions and write their StackTrace, Message, Source to a log file that you can read them.
Here is ErrorHandlingMiddleware implementation :
public class ErrorHandlingMiddleware
{
readonly RequestDelegate _next;
static ILogger<ErrorHandlingMiddleware> _logger;
public ErrorHandlingMiddleware(RequestDelegate next,
ILogger<ErrorHandlingMiddleware> logger)
{
_next = next;
_logger = logger;
}
public async Task Invoke(HttpContext context)
{
try
{
await _next(context);
}
catch (Exception ex)
{
await HandleExceptionAsync(context, ex);
}
}
static async Task HandleExceptionAsync(
HttpContext context,
Exception exception)
{
string error = "An internal server error has occured.";
_logger.LogError($"{exception.Source} - {exception.Message} - {exception.StackTrace} - {exception.TargetSite.Name}");
context.Response.StatusCode = (int)HttpStatusCode.InternalServerError;
context.Response.ContentType = "application/json";
await context.Response.WriteAsync(JsonConvert.SerializeObject(new
{
error
}));
}
}
Usage :
app.UseMiddleware<ErrorHandlingMiddleware>();

Answer 2

I don't believe this is enough information to go off of, however if you're seeing that 500 error when using the real database and the mock database is working appropriately, I would bet that your issue is with the connection string. You can also check to ensure that you're in the development environment as well.
Update: You can also try to use app.UseDeveloperExceptionPage();