Kubernetes Fundamentals and Cluster Operations — Lesson 4: RBAC, service accounts, network policies, security contexts, logging, metrics, health probes, backup, node maintenance, upgrades, troubleshooting, and recovery

Learning Objectives

• Identify the architecture and operational choices that shape RBAC, service accounts, network policies, security contexts, logging, metrics, health probes, backup, node maintenance, upgrades, troubleshooting, and recovery.
• Run normal and boundary tests and record the outcome in cluster operations runbook and incident evidence pack.
• Separate root cause from symptom when investigating a readiness probe removing healthy pods because the threshold is unsuitable for startup behavior.

Detailed Topics

• RBAC
• Service accounts
• Network policies
• Security contexts
• Logging
• Metrics
• Health probes
• Backup
• Node maintenance
• Upgrades
• Troubleshooting
• And recovery
• Decision ownership, prerequisites, and acceptance evidence for RBAC, service accounts, network policies, security contexts, logging, metrics, health probes, backup, node maintenance, upgrades, troubleshooting, and recovery
• Relevant access, security, capacity, dependency, performance, recovery, and support considerations

Instructor Demonstration

Using realistic infrastructure, identities, and workloads, the instructor demonstrates RBAC, service accounts, network policies, security contexts, logging, metrics, health probes, backup, node maintenance, upgrades, troubleshooting, and recovery. Checkpoints are captured in cluster operations runbook and incident evidence pack, with discussion of alternatives, side effects, and acceptance conditions.

Hands-On Exercise

Complete a guided task covering RBAC, service accounts, network policies, security contexts, logging, metrics, health probes, backup, node maintenance, upgrades, troubleshooting, and recovery. Establish a working baseline, reproduce “a readiness probe removing healthy pods because the threshold is unsuitable for startup behavior,” isolate the responsible configuration or dependency, apply a reversible fix, and update cluster operations runbook and incident evidence pack with before-and-after proof.

1. Confirm scope, access, sample workloads, and acceptance criteria.
2. Perform the configuration or operation using a controlled sequence.
3. Inspect outputs and downstream effects rather than relying on task status alone.
4. Close with a support note, preventive action, and reproducible validation step.

Scenario Analysis

• Clarify the service trigger, affected components and roles, prerequisites, and acceptable result for RBAC, service accounts, network policies, security contexts, logging, metrics, health probes, backup, node maintenance, upgrades, troubleshooting, and recovery.
• Compare at least two implementation or correction choices and identify which evidence would distinguish them.
• Decide how cluster operations runbook and incident evidence pack should be reviewed, approved, retained, and handed to the next owner.

Troubleshooting Guidance

When RBAC, service accounts, network policies, security contexts, logging, metrics, health probes, backup, node maintenance, upgrades, troubleshooting, and recovery produces an unexpected result, reproduce the issue with the same scope, identity, workload, and time context. Inspect cluster operations runbook and incident evidence pack, test whether “a readiness probe removing healthy pods because the threshold is unsuitable for startup behavior” explains the evidence, apply the smallest reversible correction, and retest an unaffected path for regression.

Validation Checklist

• Prerequisites and role permissions for RBAC, service accounts, network policies, security contexts, logging, metrics, health probes, backup, node maintenance, upgrades, troubleshooting, and recovery are confirmed before execution.
• The observed result agrees with expected values documented in cluster operations runbook and incident evidence pack.
• Exceptions are explained with evidence instead of being hidden by manual correction.
• The final record names the approver, monitoring point, and next improvement action.

Lesson Outcome

Learners can apply RBAC, service accounts, network policies, security contexts, logging, metrics, health probes, backup, node maintenance, upgrades, troubleshooting, and recovery, explain the decisions made, and defend the result with cluster operations runbook and incident evidence pack.