There are several options for running automation. The easiest way to run it is to install Leiningen and its runproject plugin
Run
$ lein runproject com.redhat.qe/katello.auto 1.0.0-SNAPSHOT -h
to get a list of command line options.
An example command line would be
$ lein runproject com.redhat.qe/katello.auto 1.0.0-SNAPSHOT -s https://my.host/katello katello.tests.suite/katello-tests katello.tests.suite
where the last argument is the test group to run. See suite file for list of available groups.
By default this will start up several firefox browsers and run the specified tests in parallel.
After the tests finish running, there will be a file testng-report.xml in the current directory. You can either view this file directly in an editor or browser, or if you prefer a nicely formatted HTML report, Jenkins with the TestNG plugin can generate one for you. The internal Red Hat QE Jenkins server has a job set up to display the result - just upload the xml file.
If you are running your own Jenkins server, this job is very easy to set up. Just add a file parameter testng-report.xml, and then check the box Publish TestNG Results and fill in *.xml.