CDN in a Box: services.edge.build contains unsupported option: 'target'

[zrhoffman]

This Bug Report affects these Traffic Control components:

• CDN in a Box

Current behavior:

Running CDN in a Box with docker-compose version 1.25.5 fails:

ERROR: The Compose file './docker-compose.yml' is invalid because:
services.edge.build contains unsupported option: 'target'
services.mid-01.build contains unsupported option: 'target'
services.mid-02.build contains unsupported option: 'target'

According to the Compose file version 2 spec, the target option should only be supported in Compose file versions 2.3 and higher.

Expected behavior:

CDN in a Box should work for all docker-compose versions supporting the Compose file version used by CDN in a Box (currently 2.1).

Steps to reproduce:

cd infrastructure/cdn-in-a-box
curl -LO https://github.com/docker/compose/releases/download/1.25.5/docker-compose-Darwin-x86_64
chmod +x docker-compose-Darwin-x86_64
./docker-compose-Darwin-x86_64 ps