use native docker, not require docker-machine about sbt-docker-compose

[kurtkopchik]

Hi @fommil, the plugin supports:

• Docker Toolbox
• Docker for Mac
• Native Docker on Linux (which we also use on our CI servers)

docker-machine should not be required as our CI servers also run native docker. Can you provide me with the logs and error that you are seeing? Which environment the plugin detects is in the output from dockerComposeUp.

We check if docker-machine should be used based on the existence of the environment variable DOCKER_MACHINE_NAME. Is that defined on your linux build machines for some reason?
def isBoot2DockerEnvironment: Boolean = sys.env.get("DOCKER_MACHINE_NAME").isDefined

[fommil]

ok, thanks. This is probably a false route of me trying to investigate #70