How to reliably identify master nodes in a cluster?

General Discussions
1

Hi,

I have a use case where I want to ensure that a pod runs on one of the master nodes. I am planning to use “Node affinity” feature to achieve this but I need a label that is set only on master nodes. It seems that “node-role.kubernetes.io/master” fits that bill even though I can’t find any reliable documentation pointing to this label as any kind of standard.

Can someone clarify if this label is indeed a standard? If not, is there any other label on master server that can be used reliably for this purpose?

Thanks in advance,
Raghu

2

There is not an official standard. Different tools are free to set up clusters in different ways, and there may not even be a concept of a “master node” in some environments. Kubeadm uses the node-role label, as do some others.