How to add roles to nodes in Kubernetes?

Question

When I provision a Kubernetes cluster using kubeadm, I get my nodes tagged as "none". It's a known bug in Kubernetes and currently a PR is in progress.

However, I would like to know if there is an option to add a Role name manually for the node.

root@ip-172-31-14-133:~# kubectl get nodes
NAME               STATUS    ROLES     AGE       VERSION
ip-172-31-14-133   Ready     master    19m       v1.9.3
ip-172-31-6-147    Ready     <none>    16m       v1.9.3

Waterlog

Answer 1

This worked for me:

kubectl label node cb2.4xyz.couchbase.com node-role.kubernetes.io/worker=worker

NAME                                          STATUS    ROLES           AGE       VERSION
cb2.4xyz.couchbase.com                          Ready     custom,worker   35m       v1.11.1
cb3.5xyz.couchbase.com                          Ready     worker          29m       v1.11.1

I could not delete/update the old label, but I can live with it.

Ruminant

You can delete "custom" role with command kubectl label node cb2.4xyz.couchbase.com node-role.kubernetes.io/custom- – Caia

same answer <> better answer :) – Collotype

Is there a an actual reason why you need to add worker=worker and not simply node-role.kubernetes.io=worker? Is there a convention people should abide by? – Trifoliate

Oh, I see. My version doesn't change the ROLES column actually :) But this works though and it seems simpler and more elegant: kubectl label node cb2.4xyz.couchbase.com node-role.kubernetes.io/worker="" – Trifoliate

This command removed the master role from my three k8s nodes: kubectl label node k8s1 k8s2 k8s3 node-role.kubernetes.io/master- Hope this helps. (k8s=1.21.13) – Sanjay

Answer 2

A node role is just a label with the format node-role.kubernetes.io/<role>

You can add this yourself with kubectl label

Capillary

Exact command would look like this: kubectl label node aNodeName node-role.kubernetes.io/custom= – Ephrem

just to add that kubernetes.io/role=<role_here> works as well – Afflux

You shouldn't use kubernetes.io/role anymore. github.com/kubernetes/enhancements/blob/master/keps/sig-auth/… – Tuning

Yeah this no longer is supported to set via kubelet args from Kubernetes version 1.16. Does anyone know a way to set it at the time of launching the workers? Thanks in advance. – Imperceptive

I'm also looking for the best way to do this post k8s version 1.16. Any progress here? – Mediatize

Answer 3

Default

Add Role

kubectl label node <node name> node-role.kubernetes.io/<role name>=<key - (any name)>

Remove Role

kubectl label node <node name> node-role.kubernetes.io/<role name>-

Smoothen

Answer 4

Before label:

general@master-node:~$ kubectl get nodes
NAME          STATUS   ROLES    AGE   VERSION
master-node   Ready    master   23m   v1.18.2
slave-node    Ready    <none>   19m   v1.18.2

kubectl label nodes <your_node> kubernetes.io/role=<your_label>

In my case slave-node e.g.

kubectl label nodes slave-node kubernetes.io/role=worker

After label:

general@master-node:~$ kubectl label nodes slave-node kubernetes.io/role=worker
node/slave-node labeled
general@master-node:~$ kubectl get nodes
NAME          STATUS   ROLES    AGE   VERSION
master-node   Ready    master   24m   v1.18.2
slave-node    Ready    worker   21m   v1.18.2

You can also change the label. Just put --overwrite

kubectl label --overwrite nodes <your_node> kubernetes.io/role=<your_new_label>

e.g.

kubectl label --overwrite nodes slave-node kubernetes.io/role=worker1

After overwriting the label:

general@master-node:~$ kubectl label --overwrite nodes slave-node kubernetes.io/role=worker1
node/slave-node labeled
general@master-node:~$ kubectl get nodes
NAME          STATUS   ROLES     AGE   VERSION
master-node   Ready    master    36m   v1.18.2
slave-node    Ready    worker1   32m   v1.18.2

Dickenson

repeatedly running is only appending the role not updating it. – Whose

Answer 5

Add Roles

$ kubectl get nodes 

master  Ready    control-plane,master   166m    v1.21.1
worker1  Ready    worker                 48m     v1.21.1
worker2  Ready    worker                 16m     v1.21.1
worker3   Ready    worker                 9m57s   v1.21.1    

$ kubectl label node worker1  node-role.kubernetes.io/worker=worker

$ kubectl label node worker2  node-role.kubernetes.io/worker=worker

$ kubectl label node worker3  node-role.kubernetes.io/worker=worker

In case if you wanted to overwrite, please use this below command.

$ kubectl label node worker1  node-role.kubernetes.io/worker=worker --overwrite   

Klump

You can choose your node to have any role like node-role.kubernetes.io/testing=testing-worker and node-role.kubernetes.io/system=system-worker... The column ROLES will display the value(s) separated by comma in case multiple values exist – Phalansterian

Answer 6

In my case i was able to do that with below commands

kubectl label nodes ip-10-0-47-13.ec2.internal kubernetes.io/role=worker

Output

node/ip-10-0-47-13.ec2.internal labeled

mansoor.hasan@PURE-DEV-MANSOORHASAN EKS % kubectl get nodes                                                       
NAME                         STATUS   ROLES    AGE    VERSION
ip-10-0-47-13.ec2.internal   Ready    worker   161m   v1.20.15-eks-fb459a0

Elope

Answer 7

On top of everything that has already been answered since k8S 1.16, the kubernetes.io/ and k8s.io/ prefixes are reserved for Kubernetes core components.

The suggested way is to create your own namespace to label a kubernetes node by simply reproducing the kubelet way.

For example as a label key node-role.[your-domain]/[role]=. No label value is needed, the label key is actually a tag.

kubectl label node [node-name] node-role.[your-namespace]/[role]=

Where:

• node-name is your node name (returned by kubectl get node)
• your-namespace is the "domain" of your namespace (eg. acme.org)
• role is the node role, (eg. database)

For example:

kubectl label node node001 node-role.acme.org/database=

Dugan