Description

I noticed when running docker compose build on a project that some warnings were printed in the output

 => WARN: FromAsCasing: 'as' and 'FROM' keywords' casing do not match (line 4) 

I found that the base docker command supports

docker build --check .

• https://docs.docker.com/build/checks/
• https://docs.docker.com/reference/build-checks/

And this will flag and fail if there are any warnings present. This would be very valuable to have in CI, and something that Compose could make convenient for Compose projects:

docker compose build --check

This would output the same as docker build --check . for each service that is built and return a failing status code if any do not pass the checking.