StaticFiles that return a 404 could use more diagnostic information

[Tratcher]

From @csharpfritz on May 5, 2018 16:36

A little diagnostic information when logging a 404 for a static file would be very helpful.

Perhaps adding something like "searched in folder '/app/wwwroot/lib/WHATEVER'" would be beneficial to help debug simple configuration errors

Copied from original issue: aspnet/KestrelHttpServer#2549

[Tratcher]

There is a debug log:
https://github.com/aspnet/StaticFiles/blob/afdb39309506711a60aaf6ac1a3216cf73989b4c/src/Microsoft.AspNetCore.StaticFiles/StaticFileMiddleware.cs#L89
https://github.com/aspnet/StaticFiles/blob/afdb39309506711a60aaf6ac1a3216cf73989b4c/src/Microsoft.AspNetCore.StaticFiles/LoggerExtensions.cs#L47-L50

It doesn't know the directory, that's abstracted via the IFileProvider.

Also, the static file middleware doesn't return 404's, it falls through and you only get a 404 if you reach the end of the pipeline without something handling it.

[shirhatti]

Closing as this isn't actionable. We believe there is enough fidelity of information in the debug log.