Kubernetes notes

Collection of my different Kubernetes notes mostly in context of Azure Kubernetes Service (AKS) or Azure Arc-enabled Kubernetes but also some that are also relevant for vanilla Kubernetes.

Super important topics to understand

• Understand the Kubernetes release cycle
  • ~3 releases per year
  • 3 minor versions supported at a time
  • Support window is one year
• Understand Azure Kubernetes Service (AKS) Kubernetes Release Calendar

All of the above just means that

There is no such thing as Kubernetes Long-term support (LTS)*

and

Due to frequent releases you need to upgrade at least once per year

and

You need to plan your cluster upgrades

because many things might break because of Kubernetes API deprecations. See Don't fall behind the Kubernetes changes blog post for API deprecation examples.

*: Microsoft has added LTS support for AKS clusters. Read more from Long Term Support (LTS).

Playgrounds

Different playgrounds have been created for testing very specific scenario. They also contain simple deployment script either written in bash or PowerShell which you can run line by line and replicate that environment for your own testing purposes.

Storage

Playground AKS Storage

Monitoring

Playground AKS monitoring

Identity

Playground AKS Identity

Cluster with Azure AD Auth

Maintenance

Playground AKS Maintenance

Playground AKS Scaling

Windows

Playground AKS Windows

Networking

Playground AKS Networking

Playground Private AKS

Playground for AKS and AGIC (Application Gateway Ingress Controller)

Development

Kubernetes Probe Demo

Playground AKS GitOps

Playground ACR (with AKS)

Multi-tenancy

Playground-k8s-multi-tenancy

Repository contains discussion topics around multi-tenancy options.

Azure Red Hat OpenShift (ARO)

Playground for Azure Red Hat OpenShift (ARO)

Azure Arc

Azure Arc-enabled Kubernetes

Azure Application Services

Misc

kubernetes webhook controller in C#

End-to-end scenarios

AKS Workshop

Tools

Check tools page for more information about handy tools for your automation scenarios.

Discussion topics

• Development process
• Automation
• Add-ons, extensions, and other integrations with Azure Kubernetes Service

  Add-ons are a fully supported way to provide extra capabilities for your AKS cluster. Add-ons' installation, configuration, and lifecycle is managed by AKS.

  • Support and Who ya gonna call?
• In-cluster vs. out-of-cluster components
  • Database or messaging service from PaaS or DIY
  • Support to handle support for DIY!
• GitOps vs. Traditional CI/CD a.k.a. kubectl apply ...
• Multi-tenancy
• Cluster management
  • RACI
  • Operational tasks
  • Monitoring
  • Cluster upgrades
  • Application manifest updates
  • You need to understand Kubernetes specific details -> Certified Kubernetes Administrator (CKA) required?
• Monitoring
  • App vs. Cluster monitoring
  • Innerloop development & microservice debugging