Hands-on Lab·Certified Kubernetes Administrator
What Kubernetes Is and What It Does
Kubernetes is a database of desired state with programs that keep reality matching it. That one sentence explains almost every behaviour, including the ones that surprise people, and every claim in it can be shown with a command.
Foundations Guide 1 of 103 Beginner
- Kubernetes1.36.4
- Cluster1 node
- Runtimecontainerd 2.2.6
- TimeAbout 30 min
- Reviewed21 August 2026
Written against the versions above. Nothing here is version-specific. The resource and group counts vary with what is installed on a cluster.
| Server Name | IP Address | OS | Roles | CPU | RAM | HDD |
|---|---|---|---|---|---|---|
| CKA4001 | 192.168.0.191 | Ubuntu 26.04 LTS | Control Plane Node, Worker Node | 2 Core | 4 GB | 50 GB |
Before you start
- A cluster you can reach with
kubectl. Any cluster, including a single-node one. - Familiarity with containers, though not with Kubernetes.
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It is an API before it is anything else
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Every object is a wish and a report
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Declarative means the same file twice is a no-op
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Delete a Pod and watch a controller put it back
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The ownership chain, and why it is deterministic
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Level-triggered, not event-driven
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What it will not do for you