Kubernetes

roadmap.sh: https://roadmap.sh/kubernetes

Suggested path through the Kubernetes nodes. Each node links to its lesson when written.

Nodes

Foundations

• What is Kubernetes
• Why Kubernetes / problems it solves
• Containers and container orchestration
• Kubernetes vs Docker Swarm vs Nomad
• Declarative vs imperative
• Desired state and reconciliation
• Cluster concepts overview

Architecture

• Control plane vs worker nodes
• kube-apiserver
• etcd
• kube-scheduler
• kube-controller-manager
• cloud-controller-manager
• kubelet
• kube-proxy
• Container runtime (containerd / CRI-O)
• Add-ons (DNS, dashboard, metrics)

Setup & distributions

• kubectl
• Minikube
• kind
• k3s / k3d
• kubeadm
• Managed Kubernetes (EKS, GKE, AKS)
• kubeconfig and contexts

Core objects — workloads

• Pods
• Multi-container pods and sidecars
• ReplicaSets
• Deployments
• Rolling updates and rollbacks
• StatefulSets
• DaemonSets
• Jobs
• CronJobs
• Init containers

Configuration

• Labels and selectors
• Annotations
• Namespaces
• ConfigMaps
• Secrets
• Environment variables
• Resource requests and limits
• Probes (liveness, readiness, startup)

Networking

• Kubernetes networking model
• Services (ClusterIP, NodePort, LoadBalancer)
• Headless services
• Service discovery and DNS
• Ingress
• Ingress controllers
• Gateway API
• Network policies
• CNI plugins (Calico, Cilium, Flannel)

Storage

• Volumes
• PersistentVolumes
• PersistentVolumeClaims
• StorageClasses
• Dynamic provisioning
• CSI drivers
• Volume access modes

Scheduling

• How the scheduler works
• Node selectors
• Affinity and anti-affinity
• Taints and tolerations
• Topology spread constraints
• Pod priority and preemption
• Resource quotas and LimitRanges

Security

• Authentication
• Authorization and RBAC
• Service accounts
• Admission controllers
• Pod security standards / admission
• Security contexts
• Secrets encryption at rest
• Image and supply-chain security

Scaling & availability

• Horizontal Pod Autoscaler
• Vertical Pod Autoscaler
• Cluster Autoscaler
• Pod Disruption Budgets
• Self-healing and reconciliation
• High-availability control plane

Observability & operations

• kubectl logs and exec
• Events
• Metrics Server
• Prometheus and Grafana
• Logging (Loki, EFK stack)
• Tracing
• Debugging pods and nodes

Extending & ecosystem

• Custom Resource Definitions (CRDs)
• Operators and the operator pattern
• Helm
• Kustomize
• GitOps (Argo CD, Flux)
• Service meshes (Istio, Linkerd)
• Cluster upgrades and lifecycle

Resources

See resources.md.

Project ideas

• Stand up a local kind cluster and deploy a 3-tier app with Deployments, a Service, an Ingress, and a Postgres StatefulSet backed by a PersistentVolumeClaim.
• Package an application as a Helm chart with configurable values, then set up Argo CD to deploy it from a Git repo via GitOps.
• Configure Horizontal Pod Autoscaling on a CPU-bound workload, load-test it, and dashboard the scaling behavior in Prometheus + Grafana.