How to set service-node-port-range and then be able to deploy services using the new port range?

Question

I have a requirement that a test server should use the port range 20000 - 22767

I edited the kubeadm-config with the command

kubectl edit cm

Answer 1

I too couldn't find any docs on kubeadm configuration. The following works for me:

# your current k8s version
KUBE_VERSION=v1.14.1
KUBEADM_CONFIG=kubeadm-config.yaml

# save current kubeadm config
kubeadm config view > $KUBEADM_CONFIG

# add desired port range
vi kubeadm-config.yaml

  apiServer:
    extraArgs:
      authorization-mode: Node,RBAC
+       service-node-port-range: 20000-22767

# save kubeadm config into a configmap
kubeadm config upload from-file --config $KUBEADM_CONFIG

# check changes
sudo kubeadm upgrade diff --config $KUBEADM_CONFIG

# apply changes
sudo kubeadm upgrade apply $KUBE_VERSION --config $KUBEADM_CONFIG

Answer 2

It is possible to update the service-node-port-rangefrom it's default values.

I updated the file /etc/kubernetes/manifests/kube-apiserver.yaml with --service-node-port-range=20000-22767.

The apiserver was restarted and the port range was updated.

I wrote a blog post about it.