Test Keepalived failovers with Molecule

[tobiashuste]

It is a crucial part to test that the failover procedure works as expected after changes have been made. For that reason we need to test this within Molecule's verify stage. In order to do so we will set up two keepalived / haproxy instances and a back-end server which is a dummy nginx web-server. If one keepalived / haproxy instance is stopped the other need to take over and the back-end still needs to be available.

Created from https://gitlab.com/hifis/ansible/keepalived-role/-/issues/8