With Docker for Mac, the Docker team removed a pretty hefty load of frustration from developers - no more docker-machine and setting environment variables for docker tcp communication.

There are drawbacks though - the big one for me is separation of project spaces. docker-machine lets a developer logically group containers into a VM that can be reset or destroyed without affecting the others. Container ports won’t collide between projects, and you can bind DNS for a given project to be able to refer to it locally.

That last one is important to me. When I spin up a web application locally, I don’t want to have to run docker-machine ip vm-name to find out where to point my browser or API client. (Plus, a local IPV4 address isn’t very descriptive.) I could edit my /etc/hosts file, but if the machine’s IP changes then I have to edit it.

The solution is to spin up a small Avahi container alongside my web application with docker-compose. Avahi is a Linux implementation of multi-casting DNS, which is shipped on Mac OSX as Bonjour. This lets you use <VM-name>.local as the DNS entry for the VM on your local network.

So, for example, with a basic wordpress setup:

version: '2'
        image: 'enernoclabs/avahi:latest'
            driver: 'none'
        network_mode: 'host'
        image: 'mariadb'
            MYSQL_ROOT_PASSWORD: 'foobarbazzhands'
        image: 'wordpress'
            - '8080:80'
            WORDPRESS_DB_PASSWORD: 'foobarbazzhands'

Put the above in your docker-compose.yml, then:

# Start the VM
$ docker-machine create -d virtualbox wordpress

# Set your environment variables
$ eval "$(docker-machine env wordpress)"

# Start the containers
$ docker-compose up

Then in your browser, go to http://wordpress.local:8080 to see your running Wordpress app!