How to reliably identify master nodes in a cluster?


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 “” 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,

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.