Kubernetes visual lab

Learn Kubernetes by watching the cluster think.

A lightweight canvas-style teacher for pods, nodes, scheduling, labels, resources, taints, and tolerations. This first version is a fake cluster with real scheduling rules explained step by step.

Lessons

Nodes

Pods

First Pod Scheduling

Understand that Kubernetes schedules Pods onto Nodes.

Control Plane

API Server

Scheduler

Controllers

etcd state store

worker-a

4 CPU, 8 Gi memory

zone=eastdisk=standard

CPU0/4

Memory0/8

Run scheduler to place pods

worker-b

4 CPU, 8 Gi memory

zone=westdisk=standard

CPU0/4

Memory0/8

Run scheduler to place pods

Pods Waiting For Scheduling

web-pod

1 CPU / 1 Gi

Concept

The API server records the desired Pod. The scheduler chooses a suitable worker node. The kubelet on that node starts the containers.

Try This

Find the desired Pod in the control plane.
Follow the scheduler event that chooses a node.
Notice the Service selects pods by label, not by node.

Service Selector

app=web

Services route to pods whose labels match this selector, even if those pods move to another node.

Scheduler Events

Prediction mode

Before running the scheduler, inspect selectors, taints, and requests. Then compare your guess with the events.

Mental Model

desired state
  -> API server records objects
  -> scheduler filters nodes
  -> scheduler binds pods
  -> kubelet starts containers
  -> controllers keep reconciling

The lab starts small on purpose. The aim is to make the invisible control loop visible before adding real manifests or a terminal.