docker-compose version important? #4
Description
The default versions of docker.io and docker-compose that you install when you use the standard repos provided via apt-get in Ubuntu 16.04.3 complain when I run docker-compose --build:
$ sudo docker-compose up --build
ERROR: Version in "./docker-compose.yml" is unsupported. You might be seeing this error because you're using the wrong Compose file version. Either specify a version of "2" (or "2.0") and place your service definitions under the `services` key, or omit the `version` key and place your service definitions at the root of the file to use version 1.
For more on the Compose file format versions, see https://docs.docker.com/compose/compose-file/
I switched the version to 2 in the docker-compose.yml file, and it works, but was there something in 3 we needed to make all of this work, or is version 2 of the docker-compose engine sufficient?