Recover capacity and placement after a worker loss
A hands-on CKA lab. You produce the real artefact and 8 automated checks verify it behaves the way the exam expects.
- Certification
- CKA
- Format
- Artifact workspace
- Difficulty
- medium
- Estimated time
- 35 min
- Automated checks
- 8
The brief
Repair invoice.yaml. Preserve apps/invoice (apps/v1 Deployment), three replicas, the invoice container and registry.example/invoice:6 image, with matching controller/template labels. Each replica must request at least 700m CPU and 384Mi memory; declare limits no smaller than requests and no larger than 1600m CPU/1536Mi memory. Requests reserve scheduling capacity; limits do not. Without admission defaults, a missing request inherits that resource's declared limit. All three replicas must fit jointly on eligible nodes in both stages. Normal residual CPU/memory: worker-a=1800m/1024Mi, worker-b=1400m/1024Mi, worker-c=750m/512Mi, overflow=3/2Gi, platform=8/8Gi, cordoned=8/8Gi. The loss stage removes worker-a and changes nothing else. All nodes are Ready and disk=ssd, zone=east. pool=app on worker-a/b/c and cordoned; pool=overflow on overflow; pool=platform on platform. overflow has dedicated=overflow:NoSchedule, platform has reserved=platform:NoSchedule, and cordoned is unschedulable; other nodes have no taints. Approved destinations are worker-a/b/c and overflow. Keep every other node ineligible, even if a witness packing could avoid it. nodeSelector ANDs with required nodeAffinity; terms OR together and expressions within each term AND together. Hard taints need matching tolerations, and tolerations cannot bypass cordon or readiness. Use compact requests on application nodes, or larger requests with approved overflow access. The supported subset is one Deployment with identity/selectors, one container's CPU/memory requests and limits, nodeSelector, required nodeAffinity and untimed tolerations. Inspect each stage's eligible nodes and actual packing, then repair without Reset.
What the checks verify
Your work is graded on 8 independent properties, not on matching one reference answer.
- Supported Deployment API fields, quantities and selector/toleration types are valid.
- The supplied namespace, workload/container identity, image and three replicas are preserved.
- Per-replica requests reserve at least 700m CPU and 384Mi memory.
- Both resource limits cover their requests and respect the 1600m/1536Mi safety budget.
- Every eligible node in every stage is an approved workload destination.
- Placement, readiness, cordon and hard taints leave eligible nodes in both stages.
- All three replicas fit jointly on actual eligible nodes in normal operation.
- All three replicas fit jointly after the supplied worker-a loss.
Where this sits in the CKA blueprint
- Domain
- Workloads and Scheduling
- Objective
- Admission and Scheduling
- Skill
- Resources and Placement Constraints
Part of CKA preparation
Labs are written by ExamNova to teach the decisions the exam tests. They are not reproductions of vendor lab content.