Azure App Service - write to filesystem - ASP.NET web application

Question

I have an ASP.NET web application, created in Visual Studio 2017.

In the application there is a form, where the users can upload files. When files are uploaded, I proces

Answer 1

You should never use absolute paths on server components. Try something like this for instance

var folder = Environment.GetFolderPath(System.Environment.SpecialFolder.CommonApplicationData);
var filePath = Path.Combine(folder, Request.Files["file"]);

Answer 2

Use %TEMP%, which on Azure App Service (Windows) resolves to d:\local. That's the local machine disk, not network storage, so significantly faster. It gets wiped on app restart so code accordingly.

var tempDirectoryPath = Environment.GetEnvironmentVariable("TEMP");
var filePath = Path.Combine(tempDirectoryPath, Request.Files["file"]);

If you want durability use Blob Storage instead.