I am trying to evaluate Gravitational Teleport to be for maintaining our own architecture as we will expand soon looking into building clusters. It seems a containerized cluster using Kubernetes is where the bleeding edge is happening and SSH'ing into instances seems more like something you would want to do if you want to manage a lot of VPS yourselves rather than having an immutable infrastructure.
So is Teleport a parallell technology to Container / Kubernetes / Immutable Infrastructure or is it orthogonal, as in, can be used in addition?
Teleport can be used to augment a Kubernetes cluster. Kubernetes gives you access into your pods/container, but does not handle the OS level access and control.
Teleport enterprise has extra features for Kubernetes via TeleKube- http://gravitational.com/teleport/docs/2.0/enterprise/