CKAD field manual

k8s ResourceQuota YAML example

A Quota rejects the create if the namespace would go over. A LimitRange mutates the Pod if requests were omitted.

Two cruisers, a lattice, one corridor left open. Two cruisers, a lattice, one corridor left open.
Create 
kubectl create quota app --hard=pods=5,cpu=2,memory=2Gi -n app
ResourceQuota 
apiVersion: v1
kind: ResourceQuota
metadata:
  name: app
  namespace: app
spec:
  hard:
    pods: "5"
    requests.cpu: "2"
    requests.memory: 2Gi
    limits.cpu: "4"
    limits.memory: 4Gi
LimitRange 
apiVersion: v1
kind: LimitRange
metadata:
  name: app
  namespace: app
spec:
  limits:
    - type: Container
      default:
        cpu: "200m"
        memory: 256Mi
      defaultRequest:
        cpu: "100m"
        memory: 128Mi
      max:
        cpu: "500m"
        memory: 1Gi

Fields

hard
Ceiling for the whole namespace. pods, cpu, memory, requests.cpu, limits.memory.
default
LimitRange. Injected as the container limit when the Pod omitted it.
defaultRequest
Injected as the request when the Pod omitted it. Quota often needs this.
max
Per-container ceiling. Over this, the Pod is rejected.
kubectl create quota
--hard=pods=5,cpu=2,memory=2Gi. Memory 2Gi and 2G are the same quantity.

Watch

  • A Quota on requests.cpu rejects a Pod with no CPU request. Put a LimitRange defaultRequest next to it.
  • LimitRange default is the limit, defaultRequest is the request. max is per container, not the namespace.
  • 2Gi and 2G are the same. Do not fight kubectl over the suffix.

Official docs Resource Quotas Limit Ranges

Practice these objects on a live cluster →