Services broken that start with x-

[doanac]

I hit something strange today that seems to be caused by:

https://github.com/compose-spec/compose-go/blob/b5ef325e9175ca7eb38290cc4ce1b5073c9c7b75/loader/loader.go#L209

I have a simple compose file:

version: "3"
services:
  x-kiosk:
    image: busybox:latest
    command: "sleep 10m"

When I call proj.WithServices, I get 2 two services. "x-kiosk" and one named "extensions". I'm not sure I fully understand this portion of the spec. However, I think that groupXFieldsIntoExtensions needs to skip service keys while recursing through the dict.

[ndeloof]

groupXFieldsIntoExtensions indeed applies the x-* reserved prefix logic everywhere, while docker-compose is not that strict. According to the spec https://github.com/compose-spec/compose-spec/blob/master/spec.md#extension

Special extension fields can be of any format as long as their name starts with the x- character sequence. They can be used within any structure in a Compose file.

so, this is valid for an extension to be set within services and MUST NOT be considered a service definition. That's a slight difference between the legacy implementation in docker-compose and the spec. I don't know any use of a services-level extension, but there might be use-cases for it and it would not be relevant to prevent this.

Better not use x-* as your service naming scheme