Installing PostgreSQL

PostgreSQL (https://www.postgresql.org/) is a powerful and popular open source SQL database. Even though it has nothing to do with Continuous Integration, we will need it to install the next tool, SonarQube. We will make use of PostgreSQL in the later chapters of the book, so we are not going through all this trouble just for SonarQube (but trust me, SonarQube alone is already worth it!).

Installing PostgreSQL on Ubuntu

First, we need to install PostgreSQL and some popular extensions. Ubuntu has some pretty good documentation on how to install PostgreSQL (https://help.ubuntu.com/community/PostgreSQL):

sudo apt-get update
sudo apt-get install postgresql postgresql-contrib

The installation creates a default...