Installing PostgreSQL on Ubuntu for Ruby on Rails

I currently have Ruby on Rails installed via RVM in Ubuntu 12.04. The default database is set up in SQLite3, but I'd like to switch to PostgreSQL for the purposes of pushing to Heroku. How can I accomplish this?

Here are the steps I've followed:

Install PostgreSQL and development package

$ sudo apt-get install postgresql
$ sudo apt-get install libpq-dev

Set up a user that is the same as my Ubuntu log-in

$ sudo su postgres -c psql
postgres=# CREATE ROLE <username> SUPERUSER LOGIN;
postgres=# \q

Modify Gemfile

# Remove gem 'sqlite3'
gem 'pg'

Modify database.yml in app directory

development:
  adapter: postgresql
  encoding: unicode
  database: appname_development
  pool: 5
  timeout: 5000
  username: <username>
  password:

test:
  adapter: postgresql
  encoding: unicode
  database: appname_test
  pool: 5
  timeout: 5000
  username: <username>
  password:

Run bundle install

$ bundle install

Create databases and migrations

$ rake db:create:all
$ rake db:migrate

Here are the sources I used to help:
http://mrfrosti.com/2011/11/postgresql-for-ruby-on-rails-on-ubuntu/
http://railscasts.com/episodes/342-migrating-to-postgresql
https://devcenter.heroku.com/articles/local-postgresql

For all Ubuntu 13.10 users that open this thread follow the steps below to install postresql:

sudo sh -c "echo 'deb http://apt.postgresql.org/pub/repos/apt/ precise-pgdg main' > /etc/apt/sources.list.d/pgdg.list"
wget --quiet -O - http://apt.postgresql.org/pub/repos/apt/ACCC4CF8.asc | sudo apt-key add -
sudo apt-get update
sudo apt-get install postgresql-common -t saucy
sudo apt-get install postgresql-9.2 libpq-dev

since there isn't an official Postgres repository for Ubuntu 13.10.

Then create the user as Nick explain (you can specify a password too):

sudo su postgres -c psql
postgres=# CREATE ROLE gotqn SUPERUSER LOGIN;
postgres=# \password gotqn
postgres=# \q

Note: Replace the gotqn above with whoami result:

The easiest way to create your rails application is to specify you are using postgresql as follows:

rails new Demo -d postgresql

The code above will automatically add the pg gem in your GemFile and create appropriate database.yml file:

development:
  adapter: postgresql
  encoding: unicode
  database: Demo_development
  pool: 5
  username: gotqn
  password: mypass

Note: You need to change the username and to specify the correct password if you have set such.

Then run rake db:create and start the rails server.

sudo sh -c "echo 'deb http://apt.postgresql.org/pub/repos/apt/ precise-pgdg main' > /etc/apt/sources.list.d/pgdg.list"

wget --quiet -O - http://apt.postgresql.org/pub/repos/apt/ACCC4CF8.asc | sudo apt-key add -

sudo apt-get update

sudo apt-get install postgresql-common

sudo apt-get install postgresql-9.3 libpq-dev