Heroku-like Deployment With Dokku And DigitalOcean

Over the weekend I sat down to play around with Docker/Dokku and was able to set up a small machine on DigitalOcean that basically offers Heroku-like deployment. It was surprisingly simple so here is some rough outline that should get you going.

Create a Droplet at Digitalocean

Go to DigitalOcean and create a droplet (note the comments below the screenshots):

Make sure the hostname is a fully qualified domain name, as it will be the git remote you'll push to to deploy.
When selecting the image, go to Applications and select the Dokku one.

There are some unresolved problems with Dokku on Ubuntu 13+ so if you are not just playing around you might want to setup Dokku manually. After that you're ready to hit the create button and a droplet will be created within the next minute. The last bit of server-setup that’s required is Dokku’s.

Setting up Dokku

To get to Dokku’s setup screen just steer your browser to the IP shown in the droplet’s detail view:

What you’ll see next is Dokku’s setup screen:

Add an SSH key, tick the virtualhost checkbox, and make sure the hostname is correct.

DNS Setup

To get the hostname you chose earlier actually point to your machine running Dokku you need to add two A records to the zonefile of your domain. This strongly varies between domain/DNS providers so I can’t exactly say how it’d be done for yours. Whats important is that your provider supports wildcard entries. Also the value of an A record should be only the subdomain part of the hostname you set earlier, not the complete domain.

A       <subdomain-of-hostname>      <droplet-ip>
A       *.<subdomain-of-hostname>    <droplet-ip>

# in a zonefile it’d look like this:
*.apps 10800 IN A 107.170.35.171
apps 10800 IN A 107.170.35.171

Deploying

After you’ve waited three hours for DNS servers to propagate the changes you should be able to do something like the following:

git clone git@github.com:heroku/node-js-sample.git
cd node-js-sample
git remote add digital-ocean dokku@apps.example.com:nodeapp
git push digital-ocean master

Now going to nodeapp.<dokku-hostname> should bring up “Hello World” from the app we just cloned and pushed.

If you want to add have a custom domain point to your app you'll need to either push to a remote like dokku@apps.example.com:example.com or edit the nginx.conf that comes with Dokku’s nginx plugin.

Thanks to Dokku’s Buildstep that utilizes Heroku’s opensource buildpacks you can now deploy almost every application you can deploy to Heroku to Dokku as well.

Have fun!

@martinklepsch, March 2014