Demo Request Quota

This lesson shows how to create and validate a namespace-wide ResourceQuota in OpenShift that limits the total memory requested by pods. You’ll:

Create a namespace (project).
Apply a ResourceQuota manifest that restricts requests.memory.
Deploy a sample application that requests memory and observe quota usage.

1) Create a project (namespace)

In the OpenShift web console:

Click Home → Projects → Create Project
Name: limittester (Display name can be the same)
Description: namespace for resource testing

Screenshot of the Red Hat OpenShift web console with a "Create Project" modal open showing the Name and Display name set to "limittester" and a description field being edited. The left sidebar shows the Administrator menu with Projects selected.

2) Create a ResourceQuota manifest

ResourceQuota is in the core API group (apiVersion: v1). The example below enforces a namespace-wide cap on the sum of all pod/container memory requests in the limittester namespace.

apiVersion: v1
kind: ResourceQuota
metadata:
  name: memlimit
  namespace: limittester
spec:
  hard:
    requests.memory: 512Mi

This manifest ensures the total requests.memory across the namespace cannot exceed 512Mi. Apply the manifest:

oc apply -f limit.yaml
# example output:
# resourcequota/memlimit created

Verify the quota exists:

oc get resourcequota -n limittester

Example output:

PS C:\Users\mike\Desktop> oc get resourcequota -n limittester
NAME       AGE   REQUEST                 LIMIT
memlimit   35s  requests.memory: 0/512Mi

The requests.memory column shows current usage (0 of 512Mi in this example).

ResourceQuota tracks resource requests and/or limits depending on which keys you set. In this example, we restrict requests.memory, so only memory requests are counted toward the quota.

Quick reference: ResourceQuota keys

Field	Description	Example
`requests.memory`	Sum of all container memory requests in the namespace	`512Mi`
`limits.cpu`	Sum of all container CPU limits in the namespace	`2`
`pods`	Maximum number of pods allowed in the namespace	`10`

For full available keys, see the official Kubernetes ResourceQuota documentation (link below).

3) Test the quota with a Deployment

Create a Deployment that sets a resources.requests.memory value. ResourceQuota counts the requests field, not limits (unless you also set a quota for limits.memory).

apiVersion: apps/v1
kind: Deployment
metadata:
  name: carts-db
  namespace: limittester
  labels:
    name: carts-db
spec:
  replicas: 1
  selector:
    matchLabels:
      name: carts-db
  template:
    metadata:
      labels:
        name: carts-db
    spec:
      containers:
      - name: carts-db
        image: centos/mongodb-34-centos7
        resources:
          requests:
            memory: "100Mi"
        ports:
        - name: mongo
          containerPort: 27017

Apply the Deployment:

oc apply -f deployment.yaml
# you may see a PodSecurity warning; the deployment will still be created

If you see PodSecurity warnings when applying the deployment, the resource may still be created. However, a strict PodSecurity admission policy or other admission controllers could block pod creation—verify pods are running with oc get pods -n limittester.

Check the Deployment and pods:

oc get deployments -n limittester
oc get pods -n limittester

Re-check the ResourceQuota usage after the Deployment is running:

oc get resourcequota -n limittester

Example output showing quota consumption:

PS C:\Users\mike\Desktop> oc get resourcequota -n limittester
NAME       AGE     REQUEST                       LIMIT
memlimit   3m14s   requests.memory: 100Mi/512Mi
PS C:\Users\mike\Desktop>

Now requests.memory shows 100Mi/512Mi because the Deployment requests 100Mi. If you create additional pods or increase requests, the quota usage will update. The API will refuse creation of resources that would cause the namespace to exceed the configured hard limits.

Links and references

OpenShift Documentation: https://docs.openshift.com/
Kubernetes ResourceQuota: https://kubernetes.io/docs/concepts/policy/resource-quotas/
oc CLI reference: https://docs.openshift.com/container-platform/latest/cli_reference/openshift_cli/getting-started-cli.html

Introduction

Pre-Requisite – Docker and Kubernetes

Getting Started with OpenShift

OpenShift Concepts – Projects and Users

Concepts – Builds and Deployments

Networks, Services, Routes and Scaling

Storage, Templates and Catalog

OpenShift Security

Conclusion and APPENDIX

Demo Request Quota

1) Create a project (namespace)

2) Create a ResourceQuota manifest

Quick reference: ResourceQuota keys

3) Test the quota with a Deployment

Links and references

Watch Video

​1) Create a project (namespace)

​2) Create a ResourceQuota manifest

​Quick reference: ResourceQuota keys

​3) Test the quota with a Deployment

​Links and references

Watch Video

1) Create a project (namespace)

2) Create a ResourceQuota manifest

Quick reference: ResourceQuota keys

3) Test the quota with a Deployment

Links and references