In order to add PPA repositories, you'll need to make sure you have the necessary pacakges installed to manage PPAs on your server. These may already be installed on a desktop Ubuntu distribution, but may not be present on a minimal server image.
$ sudo apt-get install python-software-properties
$ sudo apt-get install software-properties-common
$ sudo apt-add-repository ppa:hockeypuck/ppa
$ sudo apt-get update
If you want to run the PostgreSQL database on the same server as Hockeypuck, install it now:
$ sudo apt-get install postgresql
Install Hockeypuck with:
$ sudo apt-get install hockeypuck
Configure your Hockeypuck instance.