Myths, Glossary, Cheat Sheet
Everything on one page.
Let's finish the technical part with three things you will want to keep. The most common myths, a glossary of the words you now know, and a cheat sheet of commands. Pause on any screen, and take a screenshot. These pages are made to be saved.
- Myths to forget
- Words to remember
- Commands to keep
Four myths about Kubernetes
First, the myths. Myth one, Kubernetes is only for giant companies. In truth, a small team can run a cluster, especially a managed one, and the skills transfer everywhere. Myth two, Kubernetes replaces Docker images. It does not, you still build images. Myth three, pods are permanent. They are disposable, and you design for that. Myth four, Kubernetes makes apps automatically scalable and secure. It gives you the tools, but the design is still up to you.
Myths
- Only for giant companies
- Replaces container images
- Pods are permanent
- Makes apps automatically safe
Reality
- Small teams use managed clusters
- You still build images
- Pods are disposable by design
- It gives tools, you design the rest
Glossary, part one
Now, the glossary. Cluster, all the machines, managed together. Node, one machine in the cluster. Pod, the smallest unit, one or more containers. Deployment, keeps pods running, and updates them. Replica set, keeps a fixed number of pods. Service, a stable address for a group of pods. Ingress, routes outside web traffic to services. And namespace, a virtual folder inside a cluster.
Glossary, part two
More words. ConfigMap, settings outside the image. Secret, sensitive values. Volume, storage for a pod. Persistent volume claim, a request for durable storage. Stateful set, pods with stable identity. Daemon set, one pod on every node. Job and cron job, work that finishes, or repeats. And R B A C, rules for who may do what. You can now read most Kubernetes conversations.
The kubectl cheat sheet
And the cheat sheet. Get lists things. Describe shows details and events. Apply, with dash f, creates or updates from a file. Delete removes. Logs, and exec, look inside pods. Scale changes replicas, and rollout manages updates. Top shows usage. Auth can dash i tests permissions. And explain is documentation, built in. These ten commands cover most days.
| Command | Purpose |
|---|---|
| kubectl get / describe | list and inspect |
| kubectl apply -f file.yaml | create or update |
| kubectl delete | remove |
| kubectl logs / exec | look inside pods |
| kubectl scale / rollout | replicas and updates |
| kubectl top | CPU and memory |
| kubectl auth can-i | test permissions |
| kubectl explain | built-in documentation |
Summary
You now have your myths, your glossary, and your cheat sheet. One lesson remains, and it is about you. Where do you go from here? Let's build your roadmap.
Key takeaways- Myths: forgotten
- Glossary: learned
- Cheat sheet: saved