In general I want to migrate old services into kubernetes, but I'm not sure about the possibilities. The old services and the kubernetes cluster are running in two different data centers. I have old vm's/services that I'm migrating to be kubernetes-ready (creating docker-images, etc.), but this is an ongoing job and takes time.

My goal:

• Seamless partial migration of all services and deploy them to kubernetes.
• An ingress controller running in the cluster to add https (nginx,certbot).
• Old services running outside of the "clusters operating data center" should be (anyhow in a secure way) addressable by the ingress controller.

My ideas:

• Some kind of network bridge to route traffic to the other data center.
• Configure (anyhow) Kubernetes Federation with multiple ingress controllers to archive this goal.

I don't know:

• How to route or manage the traffic of the ingress controller (in k8s) to reach the correct data center.

Questions:

• Are there already concepts for such problems?
• How can I setup a secure bridge to the other data center?
• Which approaches of ingress traffic routing would you suggest?

Thank you very much!