Where should basic logic be placed?

1. Middleware
2. Depends. If they're constants, a simple PHP class with public constants will work just fine. Otherwise, it depends on your use case.

IP Blocking

@learn-by-flying This is intercepting a HTTP request and doing something if a condition isn’t met, which makes it a perfect candidate for middleware.

You could create a class that checks the IP address of the user and redirects if it’s not in your whitelist:

class VerifyUserIsUsingVpn
{
    public function handle($request, Closure $next)
    {
        $ipAddressOfVpn = '123.123.123.123';

        if ($request->ip() === $ipAddressOfVpn) {
            return $next($request);
        }

        return redirect()->to('url-containing-connection-instructions');
    }
}

Is it best practice or appropriate to place these specific small scripts in a blade file and then call them with the @yield method?

No. Blade templates are for rendering content, not for doing complex logic like checking the user’s IP address.

Is there a way to define some master global variables for the entire framework?

I’m guessing you’re using to have a file you include with a load of variables/constants. Instead, you can organise your “global” variables into configuration files.

Without knowing what “global” variables you are wanting to set, I can’t really give an example. But the IP address of your VPN would make a good candidate for a configuration value.

@martinbean & @devfrey thank you very much, I've got plenty to keep going.