Only supported by 2.2 and above:

(1) Individually assigned to a certain action:

some_routing: path: /some_path host: "{host}.example.com" defaults: { _controller: SomeDemoBundle:Some:exampleAction }

(2) Assign batches to a Controller

First use annotations in this Controller or write yaml routing for it, then import this group of routing, and uniformly restrict the host:

some_routing: resource: "@SomeDemoBundle/Resources/config/routing.yml" host: "host.example.com"