appengine safer dispatch.yaml routing to modules / services

This is a basic sense check question as i'm deploying a few new modules:

dispatch.yaml:

application: my-app
# No version required; this does routing independent of version.

dispatch:
  # Default module serves the typical web resources and all static resources.
  - url: "*/favicon.ico"
    module: default

  # Default module serves simple hostname request.
  - url: "simple-sample.appspot.com/"
    module: default

  # Send all mobile traffic to the mobile frontend.
  - url: "*/mobile/*"
    module: mobile-frontend

  # Send all work to the one static backend.
  - url: "*/work/*"
    module: static-backend

Wouldn't it be safer to put "*.com/mobile/*" instead of "*/mobile/*" ? In case other modules could use /mobile/ in their urls somewhere and accidentally get routed to mobile-frontend?

What if I have domain names other than .com e.g. .io?

Solution

Yes, it could be considered safer in the way you're looking at it.

For the additional .io (or other) domains you can add a rule for each of those suffixes:

- url: "*.com/mobile/*"
  module: mobile-frontend
- url: "*.io/mobile/*"
  module: mobile-frontend

Side note: you don't actually need to specify the rules for the default module - all requests not matching any rules in the dispatch files are by default routed to the default module, making such rules redundant. You can test this by making a request not matching any of your dispatch.yaml rules and watching the default module's logs.