Kubernetes training for developers

Kubernetes is an open-source container orchestration system for automating software deployment, scaling, and management.

High level overview:

source: https://kubernetes.io/docs/concepts/overview/components/

• Node = Worker node
• Control Plane = Master nodes

Node level overview:

• Kubernetes
• Container runtime
  • containerd
  • CRI-O
  • Docker Engine
• OS (mostly linux)

Workloads

• Deployments
• Statefulsets
• DaemonSets
• Jobs
• CronJobs
• Pods

Storage

• Storage Classes
  • allowVolumeExpansion
• Persistance Volumes
  • Volume Mode
    • Filesystem
    • Block
  • Access Modes
    • RWO - ReadWriteOnce
    • ROX - ReadOnlyMany
    • RWX - ReadWriteMany
    • RWOP - ReadWriteOncePod
• Persistance Volume Claims

Configuration

• Config Maps
• Secrets
• Secret managers
  • Hashicorp Vault
    • Secure, store and tightly control access to tokens, passwords, certificates, encryption keys for protecting secrets and other sensitive data using a UI, CLI, or HTTP API.

Network

• Services
• Endpoints
• Ingress
  • Service mesh (service networking layer)
    • Istio
      • Secure cloud-native apps
      • Manage traffic effectively
      • Monitor service mesh
      • Simplify load balancing with advanced features
      • Enforce policies

Custom resources

• Istio used / created custom resources
  • authorizationpolicies
  • destinationrules
  • envoyfilters
  • gateways
  • istiooperators
  • peerauthentications
  • requestauthentications
  • serviceentries
  • sidecars
  • telemetries
  • virtualservices
  • wasmplugins
  • workloadentries
  • workloadgroups

Tools

Name	Description
kubectl	The Kubernetes command-line tool, kubectl, allows you to run commands against Kubernetes clusters. https://github.com/kubernetes/kubectl
kubectx/kubens	Faster way to switch between clusters and namespaces in kubectl. https://github.com/ahmetb/kubectx
kyverno	Kubernetes Native Policy Management. https://github.com/kyverno/kyverno
helm	The package manager for Kubernetes. https://github.com/helm/helm
reckoner	Declaratively install and manage multiple Helm chart releases. https://github.com/FairwindsOps/reckoner
nova	Find outdated or deprecated Helm charts running in your cluster. https://github.com/FairwindsOps/Nova
artifacthub	Find, install and publish Kubernetes packages. https://github.com/artifacthub/hub
lens	Kubernetes Lens is an effective, open-source IDE for Kubernetes. https://github.com/lensapp/lens
rancher desktop	Container Management and Kubernetes on the Desktop https://github.com/rancher-sandbox/rancher-desktop/
oc	The OpenShift Command Line, part of OKD https://github.com/openshift/oc
source-to-image	A tool for building artifacts from source and injecting into container images for Openshift https://github.com/openshift/source-to-image
pluto	A cli tool to help discover deprecated apiVersions in Kubernetes. https://github.com/FairwindsOps/Pluto
kopf	A Python framework to write Kubernetes operators in just a few lines of code. https://github.com/nolar/kopf
trivy	Scanner for vulnerabilities in container images, file systems, and Git repositories, as well as for configuration issues and hard-coded secrets. https://github.com/aquasecurity/trivy
trivy-operator	Kubernetes Operator based on the open-source container vulnerability scanner Trivy. https://github.com/devopstales/trivy-operator

Commands

• Basic kubectl (+ kubectx and kubens) commands.
• Useful administrator commands.
• Basic helm commands.
• Basics of Openshift and commands.
• Basic etcd commands.
• Basics of GCP.
• Basic trivy commands.
• Basic nova commands.
• Basic pluto commands.