How ports and https are handled for Docker deploy

I’m having a similar problem. After the suggestions here, I fixed it, but autodetection is a little slow.

Perhaps a silly question, but if I want to do this in YAML, would I do it for this specific service? IE:

services:
 - type: web
    name: foo
    ... other bits and bobs ...
    envVars:
      - key: PORT
        value: 4242