Hands-on Lab·Kubernetes and Cloud Native Security Associate
ResourceQuota and LimitRange as Security Controls
Availability is part of security, and the cheapest denial of service in Kubernetes is a neighbour who asks for everything. A ResourceQuota stops that at admission - and has a side effect people usually meet by accident.
Security Fundamentals Guide 24 of 42 Intermediate
- Kubernetesapiserver v1.36.4, kubelet v1.36.3
- Runtimecontainerd 2.2.6
- CNICilium 1.18.1 - tunnel/VXLAN, with Hubble relay and UI
- Host OSUbuntu 26.04 LTS, kernel 7.0.0-29
- Built withkubeadm v1.36.3 - podSubnet 10.244.0.0/16, serviceSubnet 10.96.0.0/12
- TimeAbout 14 min
- Reviewed25 August 2026
Written against the versions above. ResourceQuota is a built-in admission controller, enabled by default. The mandatory-requests behaviour is a documented consequence of quoting `requests.*`, not a bug.
| Server Name | IP Address | OS | Roles | CPU | RAM | HDD |
|---|---|---|---|---|---|---|
| CKA5001 | 192.168.0.41 | Ubuntu 26.04 LTS | Control Plane Node (tainted NoSchedule) | 2 Core | 4 GB | 50 GB |
| CKA5001-NODE01 | 192.168.0.42 | Ubuntu 26.04 LTS | Worker Node | 2 Core | 4 GB | 50 GB |
| CKA5001-NODE02 | 192.168.0.43 | Ubuntu 26.04 LTS | Worker Node | 2 Core | 4 GB | 50 GB |
| CKA5001-NODE03 | 192.168.0.44 | Ubuntu 26.04 LTS | Worker Node | 2 Core | 4 GB | 50 GB |
Before you start
- guide 23 - the boundary a quota applies to.
-
A small quota, and a Pod that no longer fits the rules
-
The limit, enforced