RH358 – Red Hat Services Management and Automation — Lesson 3: Certificates, Authentication, Firewalls, SELinux, and Service Security

Learning Objectives

• Evaluate security, resilience, integration, and exception handling for TLS certificates, authentication, and firewalls.
• Apply SELinux and service hardening while preserving reviewable technical evidence.
• Recognize and correct the risk where the design works normally but fails under scale, dependency loss, policy enforcement, or integration delay.

Detailed Topics

• TLS certificates: apply the concept to a Linux infrastructure team deploying and automating shared enterprise services, record the relevant settings or decisions, and explain the operational consequence.
• authentication: apply the concept to a Linux infrastructure team deploying and automating shared enterprise services, record the relevant settings or decisions, and explain the operational consequence.
• firewalls: apply the concept to a Linux infrastructure team deploying and automating shared enterprise services, record the relevant settings or decisions, and explain the operational consequence.
• SELinux: apply the concept to a Linux infrastructure team deploying and automating shared enterprise services, record the relevant settings or decisions, and explain the operational consequence.
• service hardening: apply the concept to a Linux infrastructure team deploying and automating shared enterprise services, record the relevant settings or decisions, and explain the operational consequence.

Instructor Demonstration

The instructor demonstrates certificates, authentication, firewalls, selinux, and service security by tracing the relevant architecture, commands, configuration, messages, and evidence. The walkthrough highlights how the design works normally but fails under scale, dependency loss, policy enforcement, or integration delay and shows how to isolate the cause without masking dependent issues.

Hands-On Exercise

Introduce a controlled boundary condition and test recovery for Certificates, Authentication, Firewalls, SELinux, and Service Security. Add verified outcomes to the service configuration portfolio, Ansible automation repository, security evidence, and support runbook.

1. Confirm the scope, versions, access, dependencies, and success criteria.
2. Perform the workflow while recording commands, settings, output, and platform events.
3. Test one expected case and one controlled exception specific to this lesson.
4. Retest the correction and document ownership, rollback, and follow-up actions.

Scenario Analysis

• Identify which dependency most strongly influences TLS certificates in the stated scenario.
• Compare two approaches for SELinux and explain the security, reliability, and support trade-offs.
• Decide what evidence must be retained in the service configuration portfolio, Ansible automation repository, security evidence, and support runbook before operational acceptance.

Troubleshooting Guidance

Begin with the first observable difference from the expected result. Check security, integration, boundary conditions, and resilience separately, then correlate logs, events, commands, and configuration history. Do not accept the initial assumption that the design works normally but fails under scale, dependency loss, policy enforcement, or integration delay; confirm the cause with a reproducible retest.

Validation Checklist

• The required security, integration, boundary conditions, and resilience were checked and recorded.
• The normal path and a course-specific exception were tested.
• The service configuration portfolio, Ansible automation repository, security evidence, and support runbook links conclusions to commands, configuration, logs, or other objective evidence.
• Corrective actions, rollback steps, ownership, and handover notes are complete.

Lesson Outcome

Learners can apply Certificates, Authentication, Firewalls, SELinux, and Service Security, explain the observed Red Hat platform behavior, and support the result with a reviewable service configuration portfolio, Ansible automation repository, security evidence, and support runbook.