Red Hat OpenShift Developer II: Building Kubernetes Applications (DO288) — Lesson 3: Persistent Storage, Health Probes, Resources, Scaling, and Application Security

Learning Objectives

• Explain the structures, services, data, settings, roles, and dependencies governing persistent volumes and health probes.
• Implement and validate resources, autoscaling, and security contexts using reviewable evidence.
• Evaluate the condition where operators cannot explain the outcome because logs, commands, settings, and acceptance evidence were not captured consistently and select a proportionate corrective response.

Detailed Topics

• persistent volumes applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• health probes applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• resources applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• autoscaling applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• security contexts applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.

Instructor Demonstration

The instructor traces an application team packaging and delivering a production-ready service through OpenShift-native development workflows. The walkthrough connects navigation, commands, configuration logic, system messages, and evidence captured in the containerized application repository, OpenShift manifests, test evidence, and delivery pipeline design. It also tests the exception where operators cannot explain the outcome because logs, commands, settings, and acceptance evidence were not captured consistently.

Hands-On Exercise

Complete a controlled Red Hat exercise covering Persistent Storage, Health Probes, Resources, Scaling, and Application Security and preserve the verified result in the containerized application repository, OpenShift manifests, test evidence, and delivery pipeline design.

1. Confirm scope, prerequisites, versions, identities, dependencies, and acceptance criteria.
2. Execute the workflow while recording commands, settings, outputs, events, and system messages.
3. Test normal behavior, one boundary condition, and the stated exception.
4. Document corrections, evidence, ownership, retest criteria, rollback, and handover actions.

Scenario Analysis

• Identify which object, service, policy, setting, or sequence most strongly influences persistent volumes.
• Compare two defensible responses and explain technical, security, operational, and support trade-offs.
• Determine how the containerized application repository, OpenShift manifests, test evidence, and delivery pipeline design should be approved, retained, retested, and updated.

Troubleshooting Guidance

Start where expected behavior first differs from the observed result. Check prerequisites, identity, configuration order, version compatibility, connectivity, status, resource limits, and evidence separately. Treat “operators cannot explain the outcome because logs, commands, settings, and acceptance evidence were not captured consistently” as a hypothesis until commands, logs, settings, and retest outcomes confirm the cause.

Validation Checklist

• Required platform components, identities, permissions, settings, and dependencies are present.
• The containerized application repository, OpenShift manifests, test evidence, and delivery pipeline design connects each conclusion to objective, reviewable evidence.
• Normal processing, a boundary condition, dependency behavior, and the stated exception were tested.
• Corrections, ownership, retest criteria, rollback, documentation, and operational handover are complete.

Lesson Outcome

Learners can apply Persistent Storage, Health Probes, Resources, Scaling, and Application Security, explain the resulting platform behavior, and defend the outcome through the containerized application repository, OpenShift manifests, test evidence, and delivery pipeline design.