Description

A YAML node can be disabled using a "enabled" key with a value:

version: "3.4"
services:
  monitor:
    enabled: "! ${myapp.debug}"

But the code handling this feature says that no value means disabling the node too:

version: "3.4"
services:
  monitor:
    enabled: # monitor is disabled

I suggest we should remove this implicit disable with no value, and error out, as I think that enabling should be explicit too.

⚠️ We should also add unit tests on this part!!