[BUG] Error "must be a boolean" with yes scalar in Docker Compose v2.17.0

[advanceboy]

Description

I encountered an error with Docker Compose v2.17.0 when trying to load the following compose file:

version: '3'
services:
  ttt-test-pg:
    image: postgres
    environment:
      POSTGRES_PASSWORD: mysecretpassword 
    volumes:
      - type: bind
        source: ./data
        target: /var/lib/postgresql/data
        read_only: yes

The error message is below:

services.ttt-test-pg.volumes.0.read_only must be a boolean

This issue did not occur in v2.16.

Steps To Reproduce

1. Windows 10
2. Docker compose v2.17.0
3. Copy the above compose.yml
4. Then docker compose build
5. You will see the error

Compose Version

Docker: Docker version 20.10.24, build 297e128
Compose: Docker Compose version v2.17.2 @ Windows 10

Docker Environment

No response

Anything else?

Like #10411, it seems that the update to go-yaml/v3 is the root cause of this issue. While there was a breaking change from YAML 1.1 to 1.2 where yes/no and on/off are no longer considered booleans, go-yaml/v3 does support decoding to typed bool.

For compatibility reasons, it would be desirable for Docker Compose to accept yes/no and on/off as booleans when a boolean scalar is expected.

[ndeloof]

see compose-spec/compose-go#382

yes as a boolean value is indeed a legacy yaml syntax which has been removed from the YAML spec with 1.2 release in 2009 (before docker compose existed), that's just sad compose was built with a 1.0/1.1 yaml parser and did not adopted this earlier

[advanceboy]

compose-spec/compose-go#382 has been updated from the original pull request to stop support for the legacy boolean.

So, I've post a separate pull request, compose-spec/compose-go#390, solely to add support for the legacy boolean.

[ndeloof]

@advanceboy no need to start a PR competition :)
we can just debate here. I agree with you having backward compatible support with warning, at least for a transition period, would be a nicer approach. I'll discuss this with the team