I normally prefer to manage my apps on my OSX with brew
I am able to install docker, docker-compose and docker-machine
docker --version
Docker versio
I had the same problem. Docker running but couldn't access it through CLI.
For me the problem was solved by executing "Docker Quickstart Terminal.app". This is located in the "/Applications/Docker/" folder. As long as I work in this instance of the Terminal app Docker works perfectly. If a second window is needed I have to run the "Quickstart" app once more.
I have a Docker for Mac installation. Therefore I am not sure if my solution is valid for a Homebrew installation.
The "Docker Quickstart Terminal" app seems to be essentially some applescripts to launch the terminal app and a bash start script that initialise all the necessary environment variables.
Hope this helps someone else !