Why kube-router listens at 8080 on my localhost?

All about k0s
#1

Hi,

The default k0s configuration starts the kube-router service and listens at port 8080 on my localhost.

That port is only for collecting metrics from the kube-router service. I wonder how the port can bind to my localhost. Isn’t the k8s network stack separated from the localhost?

Thanks

#2

kube-router, as all/most Kubernetes networking components, is running on the host network namespace. Hence it is able to bind to hosts localhost.

Is that causing some problems or concerns?

#3

8080 is also commonly used for local HTTP test servers. It surprised me when my script stopped working. I did not expect someone would take that port.

#4

Right. It’s bit unfortunate kube-router has chosen that as the default port for metrics.

But the happy side is that you can actually configure this via k0s config:
https://docs.k0sproject.io/stable/configuration/#specnetworkkuberouter