Exposing Kubernetes Services with CoreDNS

Thu, 28 Dec 2023 14:30:00 -0600

ℹ️ Note

Originall this article only made mention of the ori-edge/k8s_gateway project. This project is now no longer maintained and development as switched over to k8s-gateway/k8s_gateway.

In my efforts to run a self-hosted Kubernetes cluster(s) in my lab. I needed a way to easily expose services outside of the cluster for easy use by me and the family/friends. In my research, I stumbled upon the Kubernetes Sig ExternalDNS. Its goal is to leverage K8 Service Annotates to provide the desired external DNS entry values and the respective configs to go along with it. However, in my attempt to make this work in a self-hosted environment with minimal deployment in a small footprint on small hardware (RPis mostly), I came across many challenges. Many of the integrations that ExternalDNS supports are focused on Cloud Provider DNS services rather than self-hosted one. Of the self-hosted DNS options, many have large footprints in their deployments. Such as the need for Databases or other services. This left me looking at my favorite DNS service, CoreDNS. However, in an attempt to get the CoreDNS ExternalDNS integration to work. I found out that it requires an etcd service to be available. As well as that the plugins the integration relies on at both the ExternalDNS and CoreDNS sides appear to not be maintained much anymore. Yet alone, the etcd approach is seen as a deprecated one in its own right.

Coredns on NerdyNik

Exposing Kubernetes Services with CoreDNS