apiVersion: quota.openshift.io/v1
kind: ClusterResourceQuota
metadata:
  name: team-quotas
spec:
  quota:
    hard:
      pods: "500"
      requests.cpu: "200"
      requests.memory: 1Ti
  selector:
    annotations:
      openshift.io/requester: "dev-team"

Project Quota Enforcement

oc describe quota -n development-team

# Check cluster quota status
oc get clusterresourcequota

Pro Tip: Combine quotas with LimitRanges (covered next) for comprehensive control.

1.2 Limit Ranges: Setting Pod Boundaries

Limit ranges define default, minimum, and maximum resource allocations:

Multi-Tier LimitRange Configuration

apiVersion: v1
kind: LimitRange
metadata:
  name: tiered-limits
spec:
  limits:
  - type: Pod
    max:
      cpu: "8"
      memory: 16Gi
  - type: Container
    default:
      cpu: "500m"
      memory: 512Mi
    min:
      cpu: "100m"
      memory: 128Mi

Common Use Cases:

• Preventing “noisy neighbor” issues

• Enforcing development vs. production standards

• Optimizing cluster resource utilization

1.3 Self-Service Project Provisioning

Enable developers while maintaining control:

# Grant self-provisioner role
oc adm policy add-cluster-role-to-group \
  self-provisioner dev-team

# Create project template
oc create -f project-template.yaml

Security Consideration: Always combine with quotas and network policies.

Section 2: Cluster Updates 

2.1 The OpenShift Update Process

Update Channels Explained:

• stable-4.12 (production recommendation)

• fast-4.12 (earlier access)

• candidate-4.12 (pre-release testing)

Update Verification Steps:

# Check available updates
oc adm upgrade

# View cluster version
oc get clusterversion

# Monitor update progress
oc logs -n openshift-cluster-version \
  -l k8s-app=cluster-version-operator

2.2 Handling Deprecated APIs

API Migration Toolkit:

# Detect deprecated APIs
oc adm inspect cluster --check-deprecated-api

# Generate migration report
oc adm migrate storage --include=deprecated-api-report

Common API Migrations:

• extensions/v1beta1 → apps/v1

• rbac.authorization.k8s.io/v1beta1 → v1

• networking.k8s.io/v1beta1 → v1

2.3 Operator Update Strategies

Approval Policy Comparison

	
Strategy
Description
Use Case




	
Automatic
Immediate updates
Non-critical workloads


	
Manual
Admin approval required
Production environments


	
Single
Stay on specific version
Legacy compatibility

Section 3: Managing Kubernetes Operators

3.1 Understanding the Operator Lifecycle Manager

OLM Architecture Components:

• CatalogSources (operator repositories)

• Subscriptions (update channels)

• InstallPlans (installation automation)

• ClusterServiceVersions (CSVs)

OLM Status Check

oc get csv -n openshift-operators
oc get subscriptions -A

3.2 Operator Installation: Console vs CLI

Web Console Method:

1. Navigate to Operators → OperatorHub

2. Search/filter operators (e.g., “PostgreSQL”)

3. Select installation mode (All namespaces/Specific namespace)

CLI Installation Workflow:

# Search available operators
oc get packagemanifests -n openshift-marketplace

# Create Subscription
cat <<EOF | oc apply -f -
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: postgresql-operator
  namespace: operators
spec:
  channel: stable
  name: postgresql-operator
  source: operatorhubio-catalog
  sourceNamespace: olm
EOF

3.3 Advanced Operator Management

Approving Manual Installations:

oc get installplan -n operators
oc patch installplan <uid> --type merge \
  -p '{"spec":{"approved":true}}'

Custom Catalog Creation:

apiVersion: operators.coreos.com/v1alpha1
kind: CatalogSource
metadata:
  name: custom-catalog
  namespace: openshift-marketplace
spec:
  sourceType: grpc
  image: quay.io/yourorg/catalog:v1

Operator Troubleshooting:

# Check operator logs
oc logs -n openshift-operators \
  -l control-plane=controller-manager

# Verify CRD availability
oc get crd | grep postgresql

Conclusion & Next Steps

This Learn OpenShift Online administration guide has equipped you with:

✔ Resource governance through quotas and limit ranges
✔ Operator lifecycle management best practices
✔ Security hardening via SCCs and network policies
✔ Update management strategies for stability

Recommended Learning Path:

1. Practice all examples in a sandbox cluster

2. Explore Red Hat’s official OpenShift courses

3. Prepare for EX280 certification with hands-on labs

4. Implement these techniques in staging environments

Final Pro Tip: Always test updates and configuration changes in a non-production environment before applying them to critical clusters.

Click here: Watch out the session 

FAQs

1. How can I learn OpenShift online for free?

Red Hat offers free OpenShift interactive learning portals like Red Hat Developer Sandbox and hands-on labs. This guide also provides free CLI exercises for cluster quotas, operators, and security configurations.

2. What’s the difference between OpenShift and Kubernetes?

OpenShift is Red Hat’s enterprise Kubernetes distribution with added features:

• Built-in CI/CD (OpenShift Pipelines)

• Developer self-service (Quotas, Templates)

• Enhanced security (SCCs, OLM)

• Simplified updates (ClusterVersion Operator)

3. How long does it take to learn OpenShift administration?

With focused OpenShift online training, you can master basics in 2-3 weeks. Certification prep (EX280) typically takes 1-2 months, depending on prior Kubernetes experience.

4. Is Red Hat EX280 certification worth it?

Yes! The EX280 exam (OpenShift Administrator) validates skills in:

• Managing cluster resources (quotas, limit ranges)

• Deploying operators via OLM

• Configuring SCCs and RBAC

• Executing cluster updates

5. Can I practice OpenShift without a paid cluster?

Absolutely! Use:

• Red Hat Developer Sandbox (Free 30-day OpenShift cluster)

• CodeReady Containers (CRC) (Local OpenShift cluster)

• Katacoda Labs (Browser-based scenarios)

6. What are the most critical Learn OpenShift Online admin skills?

From this guide’s topics:
✅ Resource Management (Quotas, LimitRanges)
✅ Operator Lifecycle Manager (OLM)
✅ Security Context Constraints (SCCs)
✅ Cluster Version Updates

7. How do OpenShift quotas improve cluster stability?

Quotas prevent resource starvation by:

• Limiting CPU/memory per project

• Restricting pod counts

• Enforcing storage requests
  (See Section 1 of this guide for YAML examples.)

8. What’s the best way to learn OpenShift security?

Start with:

• Security Context Constraints (SCCs) (Section 3)

• Network Policies (Isolating pod traffic)

• RBAC for API Access (RoleBindings, ClusterRoles)

9. How often does OpenShift release updates?

Red Hat provides:

• Minor updates every 6-8 weeks

• Major releases annually

• Long-term support for stable versions

10. Where can I find advanced Learn OpenShift Online training?

After mastering this guide:

• Red Hat Training Courses (DO280, DO380)

• OpenShift Documentation

• Community Operators (OperatorHub.io)