Lessons

Lessons live under courses/kubelings/module-N/<n>.<name>/. Each has:

• index.md — frontmatter with the playground and init/verify tasks.
• unit-1.md — the prose: situation, task, hint, the interactive check, and the solution (in a collapsible block).

Catalog — Workloads & Scheduling

Lesson	Scenario	Type
rolling-update	fix unsafe maxSurge/maxUnavailable	Fix-It
daemonset	build a node-level log collector	Build-It
statefulset	StatefulSet + headless Service (stable identity)	Build-It
jobs	make a never-finishing Job complete	Fix-It
cronjobs	stop CronJob pileup via concurrencyPolicy	Fix-It
hpa	autoscale a Deployment with an HPA (1→5)	Build-It
oomkill	right-size memory to stop an OOMKill loop	Debug-It

Running a lesson

scripts/run-challenge-local.sh <lesson> init     # build it
scripts/run-challenge-local.sh <lesson> verify   # check your fix
scripts/run-challenge-local.sh <lesson> reset    # wipe + re-init
scripts/run-challenge-local.sh <lesson> solution # print the lesson (incl. solution)

<lesson> accepts a lesson name (e.g. rolling-update), its slug, or a dir path (confined to the course tree).

Adding a lesson

tools/scaffold-lesson.sh module-2 8 ingress "Fix the broken Ingress" k8s-omni
# edit courses/kubelings/module-2/8.ingress/{index.md,unit-1.md}

# test locally
scripts/run-challenge-local.sh ingress init && scripts/run-challenge-local.sh ingress verify

# publish the whole course
labctl content push course kubelings-dbd840c8 --dir courses/kubelings --force

Task authoring rules

• init tasks build the broken/baseline state; verify exits 0 when solved, non-zero otherwise.
• Keep checks plain kubectl + bash.
• Lesson scripts run inside the kind node, not on your host — see Security. Avoid hostPath/privileged pods; the lesson namespace enforces Pod Security baseline.