Secure Kubernetes Cluster Upgrades: A Step-by-Step Guide
Secure Kubernetes Cluster Upgrades: A Step-by-Step Guide In this post, I’ll document a recent Kubernetes cluster upgrade process I implemented, focusing on security, automation, and best practices. I’ll walk through the entire process from environment assessment to verification, highlighting challenges and solutions along the way. Environment Overview Our setup consisted of a small K3s Kubernetes cluster running on Ubuntu 24.04 with: 1 master node (control plane) 2 worker nodes All nodes running an older kernel version (6.8.0-56-generic) Multiple security updates pending Upgrade Objectives Update all system packages across all nodes Apply kernel updates securely Minimize downtime by implementing a rolling upgrade Establish secure automation for future upgrades Step 1: Setting Up Secure Access The first step was to establish secure, password-less authentication using SSH keys instead of using plaintext passwords. ...