Most engineers run kubectl apply every day without knowing what happens next.
In this deep dive, we break down all 9 steps — from your YAML file to a
running container — including the parts that bite you at 2am on a Friday.
In this video, you'll learn:
- Why kubectl apply is smarter than kubectl create or replace
- The 3-way merge patch and why it matters for debugging
- What admission controllers are and how they can silently break your deployments
- How etcd, the controller manager, scheduler, and kubelet all play a role
- Server-Side Apply (SSA) in 2026 — and why you should switch now
⏱ Timestamps:
0:40 – Hook: The command you run every day
1:50 – Why understanding internals matters
2:40 – The 9-Step Overview
4:15 – Step 1: File reading
5:55 – Step 2: The last-applied annotation
7:30 – Step 3: The three-way merge patch (3-way merge)
9:35 – Step 4: The HTTP PATCH request to the API server
11:05 – Steps 5–6: Authentication and RBAC authorization
13:02 – Step 7: Admission controllers (mutating + validating webhooks)
15:10 – Step 8: etcd — the single source of truth
17:05 – Step 9: Controller reconciliation loop, Scheduler, kubelet
19:35 – Bonus: Server-Side Apply (kubectl apply --server-side)
24:25 – Summary & key takeaways
🔗 Resources & Links:
- Kubernetes docs – kubectl apply:
https://kubernetes.io/docs/concepts/cluster-administration/manage-deployment/- Server-Side Apply docs:
https://kubernetes.io/docs/reference/using-api/server-side-apply/- OPA/Gatekeeper:
https://open-policy-agent.github.io/gatekeeper/- Kyverno:
https://kyverno.io/📂 Demo Files (GitHub):
https://github.com/shazforiot/k8s-beginner-project🔔 Subscribe for weekly Kubernetes deep dives:
https://www.youtube.com/@Thetips4you📱 Follow for more:
Twitter/X: @Thetips4you
LinkedIn: linkedin.com/in/Thetips4you
#kubernetes #kubectl #devops #cloudnative #k8s #platform #sre #cka #ckad
