Kubernetes Fundamentals and Cluster Operations — Lesson 2: Pods, ReplicaSets, Deployments, StatefulSets, DaemonSets, Jobs, ConfigMaps, Secrets, services, DNS, ingress, labels, selectors, and rollout strategies

Learning Objectives

• Break down the prerequisites, components, roles, and decision points involved in Pods, ReplicaSets, Deployments, StatefulSets, DaemonSets, Jobs, ConfigMaps, Secrets, services, DNS, ingress, labels, selectors, and rollout strategies.
• Complete a controlled activity for Pods, ReplicaSets, Deployments, StatefulSets, DaemonSets, Jobs, ConfigMaps, Secrets, services, DNS, ingress, labels, selectors, and rollout strategies and capture workload deployment trace and service-connectivity test.
• Challenge the result with a selector mismatch leaving a service with no endpoints, then justify the corrective action.

Detailed Topics

• Pods
• ReplicaSets
• Deployments
• StatefulSets
• DaemonSets
• Jobs
• ConfigMaps
• Secrets
• Services
• DNS
• Ingress
• Labels
• Selectors
• And rollout strategies
• Decision ownership, prerequisites, and acceptance evidence for Pods, ReplicaSets, Deployments, StatefulSets, DaemonSets, Jobs, ConfigMaps, Secrets, services, DNS, ingress, labels, selectors, and rollout strategies
• Relevant access, security, capacity, dependency, performance, recovery, and support considerations

Instructor Demonstration

The instructor configures and tests Pods, ReplicaSets, Deployments, StatefulSets, DaemonSets, Jobs, ConfigMaps, Secrets, services, DNS, ingress, labels, selectors, and rollout strategies within a scenario aimed at a maintainable Kubernetes cluster practice covering container fundamentals, workload deployment, networking, storage, security, observability, upgrades, and incident handling. The walkthrough contrasts a valid setup with a flawed one and uses workload deployment trace and service-connectivity test to make the difference explicit.

Hands-On Exercise

Complete a guided task covering Pods, ReplicaSets, Deployments, StatefulSets, DaemonSets, Jobs, ConfigMaps, Secrets, services, DNS, ingress, labels, selectors, and rollout strategies. Establish a working baseline, reproduce “a selector mismatch leaving a service with no endpoints,” isolate the responsible configuration or dependency, apply a reversible fix, and update workload deployment trace and service-connectivity test with before-and-after proof.

1. Record the starting state, assumptions, identities, topology, and expected outcome.
2. Execute the planned workflow and collect evidence at each material checkpoint.
3. Test one valid path, one boundary condition, and the stated failure scenario.
4. Document the correction, retest result, rollback option, and follow-up owner.

Scenario Analysis

• Clarify the service trigger, affected components and roles, prerequisites, and acceptable result for Pods, ReplicaSets, Deployments, StatefulSets, DaemonSets, Jobs, ConfigMaps, Secrets, services, DNS, ingress, labels, selectors, and rollout strategies.
• Compare at least two implementation or correction choices and identify which evidence would distinguish them.
• Decide how workload deployment trace and service-connectivity test should be reviewed, approved, retained, and handed to the next owner.

Troubleshooting Guidance

Diagnose Pods, ReplicaSets, Deployments, StatefulSets, DaemonSets, Jobs, ConfigMaps, Secrets, services, DNS, ingress, labels, selectors, and rollout strategies by checking effective state, ownership, dependencies, health, logs, and recent changes. Use workload deployment trace and service-connectivity test to locate the earliest divergence. Treat “a selector mismatch leaving a service with no endpoints” as a hypothesis until the same test passes after correction and under a boundary condition.

Validation Checklist

• Prerequisites and role permissions for Pods, ReplicaSets, Deployments, StatefulSets, DaemonSets, Jobs, ConfigMaps, Secrets, services, DNS, ingress, labels, selectors, and rollout strategies are confirmed before execution.
• The observed result agrees with expected values documented in workload deployment trace and service-connectivity test.
• 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 Pods, ReplicaSets, Deployments, StatefulSets, DaemonSets, Jobs, ConfigMaps, Secrets, services, DNS, ingress, labels, selectors, and rollout strategies, explain the decisions made, and defend the result with workload deployment trace and service-connectivity test.