Docker compose problem with services key

[maurapintor]

Docker compose file format is incompatible with old versions.

Expected Behavior

The command:

docker build . -t pandavision && docker-compose build && docker-compose up

should build the container and run smoothly.

Current Behavior

The command produces, with some Docker-compose versions, the following output:

Successfully tagged pandavision:latest
ERROR: The Compose file './docker-compose.yml' is invalid because:
Unsupported config option for services: 'worker'

Possible Solution

The problem seems related to the docker-compose versions that have incompatible specifications for the expected yaml: https://docs.docker.com/compose/compose-file/compose-versioning/#versioning

A suggested solution, from this StackOverflow question, is to upgrade the docker-compose version, and specify the version number in the top of the yaml file.

Possible Implementation

1. add line in the yaml file, stating version: "3" in the header.
2. suggest minimum version required for docker-compose, i.e. at least 1.6, in the readme file.