Three fixes from an audit of the repo:
1. setup_contexts() deleted all three k8s-c?-? contexts and recreated none
unless the session was started with --hard. But './exam drill <ids>' and
'./exam drill weak' don't filter by difficulty, so hard tasks land in
hard=False sessions - and 24 of them open with "kubectl config use-context
...", which then fails outright. Q121 was unpassable that way: it says to
deploy into the context's namespace without -n, and its check requires that
namespace, so the context was the only way to learn the name. Contexts are
now created whenever a task in the session references one.
Also fixes how k8s-c2-AC's namespace was chosen: it took the first ns in the
whole session, which is arbitrary when several tasks share a context. A
context has one default namespace, so it belongs to the task that actually
reads it - Q121, now marked "ctx_ns": True.
2. restore_baseline() cleared taint keys dedicated/workload/team, but Q107
draws from pool/lane and Q307 pins maintenance=inprogress, and nothing
uncordoned a node. A leaked cordon or taint silently fails every later task
that counts pods per node (Q26/Q211 DaemonSet coverage, Q212's spread) -
W1 had been cordoned and tainted across sessions for two days. Clears all
six keys now and uncordons all three workers.
3. ttyd was launched with -W (writable) and no interface binding, so it listened
on 0.0.0.0 while the API server correctly bound localhost. That exposed an
unauthenticated root-equivalent shell with the cluster kubeconfig to the whole
network. Pinned to loopback, overridable via CKA_TTYD_INTERFACE.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Fqcio9TXkEXH35UHebTgoL
tracks/cka/solutions.py had drifted out of sync with the actual current
task text for several questions (Q06, 11, 12, 13, 14, 22, 32, 40, 109,
110, 120, 122) - wrong namespaces/resource names, missing required steps,
or output files that were never actually written. Rewrote each to match
its task's real requirements.
tracks/cka/bank_extra.py's Q33 grading check queried
`.spec.aggregationRule` on a ClusterRole, but ClusterRole has no `.spec`
field - `aggregationRule` and `rules` are top-level. Fixed the jsonpath
so a correct answer actually passes.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Fqcio9TXkEXH35UHebTgoL
Task setup scripts regenerate workspace/qNN/ on every seed, so it's
runtime output, not source - same reasoning as the earlier q03/q21
untrack. Ignore workspace/* by default, keeping q03 and q21 as the
two already-tracked seed-template exceptions.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Disruptive tasks corrupt shared state (static pod manifests, kubelet
config, CoreDNS) keyed by a "breaks" target, but a session's setup only
touches the questions it actually contains. If a task isn't re-picked in
a later session, its damage lingers indefinitely - e.g. Q39 wrecking W1's
kubelet config persisted across two unrelated TSHOOT drills that never
included Q39 again.
Add restore_baseline(), run unconditionally in begin_session() before
seeding, that repairs every known "breaks" target (scheduler,
controller-manager, CoreDNS, all three worker kubelets, W1's demo
taints) regardless of which questions are in the new session. Hard-mode-
only breaks (etcd, certs, apiserver) aren't covered yet.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
workspace/q03's Q03 setup script wipes and regenerates this base
every time the task is seeded (rm -rf "$WS/q03"; mkdir -p ...), so
these were runtime output that had been accidentally committed
rather than source files.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
The UI was light everywhere except the embedded terminal, which felt
disjointed. Switch to a cohesive dark palette with layered surfaces,
tinted state colors for pass/fail/warn/flag, and polish on buttons,
cards, overlays, and the question nav (hover/active states, shadows,
custom scrollbars).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
kind load docker-image shells out to the docker CLI internally
regardless of KIND_EXPERIMENTAL_PROVIDER, so it can't see images that
only exist in podman's store and fails when the docker socket isn't
reachable. Save each image with podman save and load the tar via
kind load image-archive, which is runtime-agnostic.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Close two of the four CKA-relevant gaps identified against Killercoda's
scenario catalog:
- Q123 (TSHOOT, hard): kube-apiserver itself crash-loops on a static-pod
manifest typo, same pattern as the existing scheduler/controller-manager
failures (Q20/Q118) but with the added twist that kubectl is completely
unusable until it's fixed, forcing node-level diagnosis (crictl,
journalctl).
- Q124 (ARCH, hard): produce a real node-join handoff file by
independently computing the CA discovery hash kubeadm join verifies
against, and finding the API server's actual in-cluster address rather
than the local kubeconfig's port-forwarded one.
Cluster-upgrade and operator-authoring remain unimplemented and are
documented as genuine infrastructure gaps in CKA_SOLUTIONS_EXPLAINED.md
(kind's node images have no apt-installable multi-version kubelet/kubeadm,
and operator authoring needs a real built/pushed image) rather than faked.
Also updates the Killercoda cross-reference table with the gaps closed,
and logs an ended drill session to history-cka.jsonl/weak-spots-cka.md.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Expand every entry with a concept section explaining the underlying
mechanism, exact commands/YAML pulled from tracks/cka/solutions.py,
and gotchas tied to what each question's grader checks actually
verify. Doc grows from ~750 to ~1540 lines.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Filled six gaps in the solutions guide (Helm, Kustomize generators,
CRD validation, cluster audit, Gateway API canary, context namespace)
so every question id in the bank (1-43, 101-122) has a section.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
The Q02/Q102 seeds tried to copy etcdctl out of the running etcd pod with
`kubectl exec -- cat`, which cannot work: registry.k8s.io/etcd is distroless
(no cat, no sh, no tar). The copy failed, stderr went to /dev/null and seeding
still printed a green tick, so the snapshot task had no etcdctl on the node.
Q102 was worse: it also ran `exec -- sh -c 'etcdctl ... snapshot save'` inside
that container, so its /opt/cka/backup.db was never created at all.
- etcd-tools.sh installs both binaries on the control-plane node, taking them
from the etcd image already in the node's containerd (offline, exactly the
server version), falling back to the upstream release tarball, then apt.
- setup.sh runs it at bootstrap; ensure_etcd_tools in the exam prelude installs
them through CKA_NODE_ACCESS when a task is seeded, so ssh/vagrant clusters
get them too, and both etcd setups now fail with a reason instead of hiding it.
- Q102 takes its snapshot with the node's etcdctl; Q02 no longer documents a
kubectl cp fallback that cannot work on a distroless image.
Co-authored-by: Junie <junie@jetbrains.com>
