Symfony Routing Host Regular Expression

I have a route in my Symfony project that should be restricted only to hosts that contains a specific word in a subdomain, a domain is not important and it will vary. Lets say this specific word is 'pre', so I want only hosts build like this (pre.anything.com, pre.anything2.co.uk, pre.anything3.us) to access certain route. Is it possible to configure it as such in a symfony routing?

routes.yaml

base_register:
    path:     /register/
    host:     "/pre/"
    defaults: { _controller: App\Controller\AppController::registerAction }

Using:

• Symfony 4.2
• PHP 7.2

Your use case is similar to the docs for subdomains : https://symfony.com/doc/4.1/routing/hostname_pattern.html#using-placeholders

You can use this config:

base_register:
    path:     /register/
    host:     "pre.{domain}"
    controller: App\Controller\AppController::register
    defaults:
        domain: '%domain%'
    requirements:
        domain: '%domain%'

and then in your parameters.yml you define your domain param where you set your default domain.

In your domain requirement you can set (.*) to catch both domain and subdomain.