Poor Docker performance on macOS is a well documented issue. This is not an Ember issue, but rather, an issue with Docker and macOS.

After months of working with a hobbled and hacked together Docker build environment, I gave docker-sync with Unison a try and it has worked wonderfully.

I can finally use Ember with Docker without a horrible performance hit! Thank you docker-sync and Unison!

I would like to point out that docker-sync has extensive documentation and you should read their docs.

For the sake of this article, I am using the Ember super-rentals demo app for demonstration.


I am assuming you have already installed Docker and are comfortable installing ruby gems on your system.

Install docker-sync.

gem install docker-sync

Clone the super-rentals app.

git clone https://github.com/ember-learn/super-rentals


Create a docker-sync.yml file in the root of super-rentals.

version: 2
    src: '.'

Create a docker-compose.yml file in the root of super-rentals.

version: '2'
    image: 'node:8.9.1'
    command: '/bin/bash'
      - super-rentals-sync:/app:nocopy

    external: true


Start docker-sync.

docker-sync start

Run our container with the synced volume.

docker-compose \
    run \
    --rm \
    --name=super-rentals \
    -p 4200:4200 \
    -p 7020:7020 \
    -w /app \

Install ember-cli in the container.

npm install -g ember-cli

Install node modules.

yarn install

Run the ember server.

ember s --live-reload-port 7020

You should now be able to access your app at http://localhost:4200 and update it like normal!


You can stop the docker-sync container like so.

docker-sync stop

At this point you should be able to use Docker and Ember like normal. You can create your own Docker image and customize these steps as you see fit.