.NET 7 map file pattern to static file serving

I there a way to serve static files with .NET 7 only for certain file patterns?

Currently I have the plain old:

app.UseStaticFiles(new StaticFileOptions
{
    FileProvider = new PhysicalFileProvider(storageDirectory),
    RequestPath = "/",
});

But I'm looking for something more link

app.UseStaticFiles(new StaticFileOptions
{
    FileProvider = new PhysicalFileProvider(storageDirectory),
    RequestPath = "/[a-b0-9\-]+/.+"
});

Is that possible somehow?

[Update 1]
I can see in the source that the path is checked with StartsWithSegments:

https://github.com/dotnet/aspnetcore/blob/main/src/Middleware/StaticFiles/src/Helpers.cs

internal static bool TryMatchPath(HttpContext context, PathString matchUrl, bool forDirectory, out PathString subpath)
{
    var path = context.Request.Path;

    if (forDirectory && !PathEndsInSlash(path))
    {
        path += new PathString("/");
    }

    if (path.StartsWithSegments(matchUrl, out subpath))
    {
        return true;
    }
    return false;
}

Seems like I need to write a custom middleware?

As per docs:

> RequestPath
> The relative request path that maps to static resources. This defaults to the site root '/'.

i.e. it will allow only to specify the folder where static resources are located.

One option you can try is the option to branch the middleware pipeline via UseWhen:

app.UseWhen(ctx => Regex.IsMatch(ctx.Request.Path.Value ?? "", ""), appBuilder =>
    appBuilder.UseStaticFiles(new StaticFileOptions
    {
        FileProvider = new PhysicalFileProvider(storageDirectory),
    }));