Kubernetes Cookbook - Second Edition

Setting up ssh public key authentication

One more thing, as mentioned previously, Ansible is actually the ssh automation tool. If you log on to host via ssh, you have to have an appropriate credential (user/password or ssh public key) to the target machines. In this case, the target machines mean the Kubernetes master and nodes.

Due to security reasons, especially in the public cloud, Kubernetes uses only the ssh public key authentication instead of ID/password authentication.

To follow the best practice, let's copy the ssh public key from your Ansible machine to the Kubernetes master/node machines:

If you've already set up ssh public key authentication between the Ansible machine to Kubernetes candidate machines, you can skip this step. ...