[keepalived][0] is a free implementation of the Virtual Router
Redundancy Protocol (VRRP), which is a simple method for automatically
assigning an IP address to one of several potential hosts based on
certain criteria. It is particularly useful in conjunction with a load
balancer like HAProxy, to provide layer 3 redundancy in addition to
layer 7. We will use it for both the reverse proxy for the public
websites and the Kubernetes API server.
[0]: https://www.keepalived.org/