#What is kubernetes nodeport how to

This way to expose a service remembers the approach used by docker: the big difference is that in docker there is one-one mapping between the NodePort and a only container in the kubernetes the NodePort, accessible to physical ip address of any node of the cluster, balances to a set of Pods that matches the label selector of the kubernetes service.įollowing a easy example that shows how to expose, by NodePort, a simple echo-server deployment running in the kubernetes cluster that has been created following the procedure described in this my article #]# vi echo-NodePort.yaml The NodePort kubernetes service gives the possibility to espose, externally to cluster, a set of pods, that share the same labels, using a port in the range 30000-32767. Let’s start to talk about the first kubernetes service: NodePort. You can find all the details on my previous article.

In this direction, after different years to work with kubernetes, I can say that the best solution doesn’t exists and it depends on your requirements: a NodePort could be preferred to ingress in a particular scenario and in other case the ingress could be better and it will be enough clear in the next part of my article.Īnother important thing to say, before starting with my dissertation, is that the NodePort is native because implemented directly by k8s-proxy daemon running in any node of the cluster instead the ingress is implemented by a external controller that, according to the information provided in the ingress kubernetes object, configures an outside or inside reverse proxy.įor better explain and compare these two approaches, I will provide some example running on a kubernetes cluster created with kubeadm. I write this article for sharing my experience in the configuration of kubernetes services to expose outside, explaining advantages and disadvantages of the two different solutions most used: NodePort and Ingress controller.