MakerSkillTree/Kubernetes Skill Tree/CHANGELOG.md

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog.

Peer Review 1 [Unreleased]

Added

• More steps to create familiarity with commonly used parts of the sprawling kubectl command.
• Steps to bringing your own application to Kubernetes:
  • "Use an image from a private container repository"
  • "Create a container from your app"
• Introduction to additional tools:
  • "Try an alternative to kubectl like K9s"
  • "Install the Kubernetes Dashboard"
• Milestones for beginner/intermediate/advanced use cases:
  • Beginner: "Deploy apps for your personal use"
  • Intermediate: "Run apps for a club on a cluster"
  • Advanced: "Host apps on the Internet from your cluster"
• Places to get more information:
  • "Explore kubectl's "Troubleshooting" section"
  • "Explore the Kubernetes Reference Guide"
  • "Explore the Kubernetes Tutorials"
• More gradual exposure to different concepts:
  • "Set up health check probes on your workloads" for the different kinds of health checks
  • "Set up two workloads that communicate" for in-cluster DNS
  • "Deploy a stateless app" the first major step after a Hello, World Pod is deploying something that doesn't need to store data.
  • "Expose a Deployment using a Service" step to show that Deployments and Pods work similarly.
  • "Create a multi-container Pod" for sidecars
  • "Use headless Services for service discovery" for service discovery
  • "Deploy a non-HTTP workload e.g. FTP server" for TCP networking, which is more primitive
  • "Optimize your workload container sizes" for cost savings and performance
  • "Set up ServiceAccounts for your workloads" for security and cluster sharing
  • "Share your cluster with a second person" for practical RBAC
  • "Configure a Deployment for high availability updates" for proper use of Deployments
• Different options to get Kubernetes clusters:
  • "Deploy a cluster in the cloud" this is what most people do.
  • "Set up a cluster from scratch on Raspberry Pis" a common approach for hobbyists with lots of info and varying degrees of difficulty depending on how deep into it you want to go.
• Basic operations needs:
  • Learn how to backup and restore your cluster
  • Make your cluster reproducible with Terraform

Changed

• "Create a basic Pod" to "Deploy a 'Hello, World!'' Pod" because it's not obvious what "basic" means.
• "Secure sensitive data with Secrets" to "Use a Secret to distribute credentials" because Secrets don't provide much security.
• Merged "Set resource requests for Pods" and "Set resource limits for Pods" to "Set resource requests and limits for workloads" because it's the same topic.
• "Perform rolling updates and rollbacks" to "Roll back a change to a Deployment" rolling updates are the default, but being able to undo a mistake is very important.
• Merged "Control Pod scheduling tolerations" and "Configure Pod affinity and anti-affinity" into "Control scheduling with tolerations and affinity" because they're similar topics.
• Replaced "Set up Persistent Volumes and Claims" and "Create StatefulSets for stateful applications" with " Deploy Wordpress and MySQL with Persistent Volumes" to focus on an outcome. This wil point you at the Kubernetes.io tutorial for stateful workloads.
• Consolidated topics related to operators and CRDs into: "Develop your own operator and CRDs". This is a niche skill, but it's good to know it's possible.
• Consolidated multiple service mesh/advanced networking related solutions to "Deploy a service mesh to your cluster"
• Consolidated multiple monitoring items to: "Set up cluster-wide logging and monitoring" and "Set up alerting for unhealthy workloads". Logging/monitoring are usually the same tool and useful by themselves.
• Many small wording changes to improve cohesion.

Removed

• "Use Kubectl to manage resources" because it has high overlap with the other skills.
• Duplicate "Expose a Pod using a Service"
• "Apply network policies to control traffic between Pods" because only some configurations support this out of the box, it silently fails otherwise which would be frustrating for a beginner.
• Skills that focus on specific parts of deploying your own cluster, these align better with a platform engineer role than a hobbyist. Some of these are now covered by deploying a cluster on a Raspberry Pi:
  • "Set up a container runtime e.g. Containerd, CRI-0"
  • "Set up ingress for external access e.g. NGINX, Traefik"
  • "Set up a multi-node cluster with kubeadm"
  • "Set up a cluster using Kubeadm"
  • "Use Cluster API"
  • "Use Kubernetes on Bare Metal"
  • "Use persistent volume provisioners"
  • "Install and configure a networking solution e.g. Calico, Flannel"
• Removed multiple items related to storage, these should be covered enough to get by with the stateful application tile:
  • "Use external storage solutions with Kubernetes"
  • "Configure storage class"
  • "Implement storage solutions with CSI drivers"
• Removed multiple skills that start to matter when you have lots of people or large clusters:
  • "Optimize costs within Kubernetes" partially covered by optimizing workloads
  • "Use OPA for policies"
  • "Perform cluster performance tuning"
  • "Implement GitOps practices" partially covered elsewhere
  • "Create a blue-green deployment" not best practice in Kubernetes
  • "Create a canary deployment" already covered with Deployments

Fixed

• Various capitalization issues.
  • Kind to kind to match their website
  • MiniKube to minikube to match their website
  • Capitalized Kubernetes types except namespace to be consistent with kubernetes.io