Preventing LoadBalancer service traffic from flowing through control plane and etcd nodes in a Kubernetes cluster with the AWS Cloud Provider

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Situation

Task

This article details how to prevent LoadBalancer type service traffic from flowing through control plane and etcd nodes, in a cluster configured with the AWS Cloud Provider.

Pre-requisites

A Rancher Kubernetes Engine (RKE) CLI or Rancher v2.x provisioned Kubernetes cluster, provisioned on EC2 instances
Separate worker nodes from control plane and etcd nodes
The AWS Cloud Provider configured

Making the changes

Nodes of a Kubernetes cluster created by Rancher/RKE, that use AWS as the cloud provider, automatically get added to service load balancers (ELB). The behavior results in both controlplane and etcd nodes routing end-user application traffic, breaking the role separations model. To prevent this, label the control plane and etcd nodes with the label node-role.kubernetes.io/master and the cloud-controller will not automatically add them to the service load balancers.

Disclaimer

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