CKAD Certified Kubernetes Application Developer (CKAD) Program Questions and Answers

Solution:

ssh ckad00043

You have two deliverables here:

Figure out what RBAC permissions the scraper Deployment needs (the logs will usually show “Forbidden” with the missing verb/resource).

Create a ServiceAccount named scraper in namespace cute-panda (and in practice, you then bind the needed permissions to it and use it in the Deployment so it actually works).

Below is the exact CKAD-style workflow.

1) Find the missing RBAC permissions (use logs + events)

1.1 Identify the pods for the Deployment

kubectl -n cute-panda get deploy scraper

kubectl -n cute-panda get pods -l app=scraper 2>/dev/null || kubectl -n cute-panda get pods

Pick one pod name and check logs:

kubectl -n cute-panda logs deploy/scraper --tail=100

If the pod is crashlooping and logs are short:

POD=$(kubectl -n cute-panda get pods -o jsonpath='{.items[0].metadata.name}')

kubectl -n cute-panda logs "$POD" --previous --tail=200

1.2 Look specifically for “Forbidden” lines

Most apps print errors like:

... is forbidden: User "system:serviceaccount:cute-panda:default" cannot list resource "pods" in API group "" in the namespace "cute-panda"

or cannot get resource "configmaps"...

or cannot watch ...

If you don’t see it in logs, check events:

kubectl -n cute-panda get events --sort-by=.lastTimestamp | tail -n 30

1.3 Extract verb/resource/apiGroup from the error

From a typical Kubernetes RBAC “forbidden” message, capture:

verb: get/list/watch/create/update/patch/delete

resource: pods, configmaps, secrets, deployments, etc.

apiGroup: "" (core), apps, batch, etc.

namespace: cute-panda (this is a namespaced permission if it’s a Role)

You may have multiple “cannot …” lines → you need to allow all of them.

2) Create the ServiceAccount scraper (required by the task)

kubectl -n cute-panda create serviceaccount scraper

kubectl -n cute-panda get sa scraper

3) Create the RBAC objects to grant the needed permissions

The task says “A Deployment needs specific RBAC permissions” — in CKAD, that usually means: Role + RoleBinding (namespaced) bound to your new ServiceAccount.

3.1 Create a Role (template you fill from the log output)

Create scraper-role.yaml:

cat <<'EOF' > scraper-role.yaml

apiVersion: rbac.authorization.k8s.io/v1

kind: Role

metadata:

name: scraper-role

namespace: cute-panda

rules:

# EXAMPLE ONLY: replace these rules with what your logs show

- apiGroups: [""]

resources: ["pods"]

verbs: ["get","list","watch"]

EOF

Apply it:

kubectl apply -f scraper-role.yaml

3.2 Bind the Role to the ServiceAccount

kubectl -n cute-panda create rolebinding scraper-rb \

--role=scraper-role \

--serviceaccount=cute-panda:scraper

Verify:

kubectl -n cute-panda get role scraper-role

kubectl -n cute-panda get rolebinding scraper-rb -o yaml

4) Update the Deployment to use the new ServiceAccount (so it actually works)

Check current SA (likely default):

kubectl -n cute-panda get deploy scraper -o jsonpath='{.spec.template.spec.serviceAccountName}{"\n"}'

Patch it to use scraper:

kubectl -n cute-panda patch deploy scraper -p '{"spec":{"template":{"spec":{"serviceAccountName":"scraper"}}}}'

Rollout:

kubectl -n cute-panda rollout status deploy scraper

Re-check logs to confirm RBAC errors are gone:

kubectl -n cute-panda logs deploy/scraper --tail=100

Solution:

Do this on ckad00027 and edit the given manifest file (that’s what the task expects).

0) Connect to correct host

ssh ckad00027

1) Open the manifest and identify the container + port

cd /home/candidate/spicy-pikachu

ls -l

sed -n '1,200p' app-deployment.yaml

Confirm the container port is 8081 in the YAML (usually under ports:).

2) Edit the YAML to add a readinessProbe

Edit the file:

vi app-deployment.yaml

Inside the Deployment, locate:

spec:

template:

spec:

containers:

- name: ...

image: ...

Add this under the container (same indentation level as image, ports, etc.):

readinessProbe:

httpGet:

path: /healthz

port: 8081

initialDelaySeconds: 6

periodSeconds: 3

Notes:

Use port: 8081 (because the app runs on 8081).

Ensure indentation is correct (2 spaces per level commonly).

Save and exit.

3) Apply the updated manifest

kubectl apply -f /home/candidate/spicy-pikachu/app-deployment.yaml

4) Ensure the Deployment rolls out successfully

kubectl -n prod rollout status deploy app-deployment

5) Verify the readiness probe is set

Check the probe from the live object:

kubectl -n prod get deploy app-deployment -o jsonpath='{.spec.template.spec.containers[0].readinessProbe}{"\n"}'

And confirm pods are becoming Ready:

kubectl -n prod get pods -l app=app-deployment

If the label selector differs, just:

kubectl -n prod get pods

kubectl -n prod describe pod | sed -n '/Readiness:/,/Conditions:/p'

That completes the task: readiness probe on /healthz, initialDelaySeconds: 6, periodSeconds: 3.

Solution:

Solution:

Solution:

ssh ckad00028

You’re seeing RBAC errors like:

User "system:serviceaccount:gorilla:default" cannot list resource "pods" … in namespace "gorilla"

That means the Pod is running as the default ServiceAccount and needs permission to list pods (and possibly also get/watch).

You must fix it by updating the Deployment (via its manifest file) and giving it the proper RBAC.

1) Confirm the error in logs

kubectl -n gorilla get deploy honeybee-deployment

kubectl -n gorilla logs deploy/honeybee-deployment --tail=200

If it’s CrashLooping and you need previous logs:

POD=$(kubectl -n gorilla get pods -l app=honeybee -o jsonpath='{.items[0].metadata.name}' 2>/dev/null || kubectl -n gorilla get pods -o jsonpath='{.items[0].metadata.name}')

kubectl -n gorilla logs "$POD" --previous --tail=200

You should see the “cannot list resource pods” line.

2) Create a dedicated ServiceAccount for the app

(Using a dedicated SA is standard practice; the task wants you to “resolve the errors”.)

kubectl -n gorilla create serviceaccount honeybee-sa

kubectl -n gorilla get sa honeybee-sa

3) Create RBAC: Role + RoleBinding (namespaced)

This will allow listing pods in namespace gorilla.

cat <<'EOF' > honeybee-rbac.yaml

apiVersion: rbac.authorization.k8s.io/v1

kind: Role

metadata:

name: honeybee-pod-reader

namespace: gorilla

rules:

- apiGroups: [""]

resources: ["pods"]

verbs: ["get", "list", "watch"]

---

apiVersion: rbac.authorization.k8s.io/v1

kind: RoleBinding

metadata:

name: honeybee-pod-reader-binding

namespace: gorilla

subjects:

- kind: ServiceAccount

name: honeybee-sa

namespace: gorilla

roleRef:

apiGroup: rbac.authorization.k8s.io

kind: Role

name: honeybee-pod-reader

EOF

Apply it:

kubectl apply -f honeybee-rbac.yaml

Quick verification (optional but very useful):

kubectl auth can-i list pods -n gorilla --as=system:serviceaccount:gorilla:honeybee-sa

Should return yes.

4) Update the Deployment manifest to use the new ServiceAccount

The manifest is at:

/home/candidate/prompt-escargot/honey bee-deployment.yaml

Because there’s a space in the filename, quote it.

4.1 Edit the file

cd /home/candidate/prompt-escargot

ls -l

vi "honey bee-deployment.yaml"

In the Deployment YAML, add (or set) this under:

spec.template.spec:

serviceAccountName: honeybee-sa

Example location:

spec:

template:

spec:

serviceAccountName: honeybee-sa

containers:

- name: ...

Save and exit.

4.2 Apply the updated manifest

kubectl apply -f "/home/candidate/prompt-escargot/honey bee-deployment.yaml"

5) Ensure rollout succeeds and errors are gone

kubectl -n gorilla rollout status deploy honeybee-deployment

kubectl -n gorilla logs deploy/honeybee-deployment --tail=200

Also confirm the pods now run with the right ServiceAccount:

kubectl -n gorilla get pods -o jsonpath='{range .items[*]}{.metadata.name}{" sa="}{.spec.serviceAccountName}{"\n"}{end}'

You should no longer see the RBAC “cannot list pods” errors.

To allow a pod to send and receive traffic only to and from specific pods, you can use network policies in Kubernetes.

First, you will need to create a network policy that defines the allowed traffic. You can create a network policy yaml file with the following rules:

apiVersion: networking.k8s.io/v1

kind: NetworkPolicy

metadata:

name: newpod-network-policy

namespace: default

spec:

podSelector:

matchLabels:

app: kdsn00201-newpod

ingress:

- from:

- podSelector:

matchLabels:

app: web

- podSelector:

matchLabels:

app: storage

This policy will only allow incoming traffic to the pod with the label app=kdsn00201-newpod from pods with the label app=web or app=storage. If you have different labels on your web and storage pods please update the matchLabels accordingly.

Once you have created the network policy, you can apply it to the cluster by running the following command:

kubectl apply -f .yaml

This will apply the network policy to the cluster, and the newpod will only be able to send and receive traffic to and from the web and storage pods.

Please note that, NetworkPolicy resource is not available by default, you need to enable the NetworkPolicy feature on your Kubernetes cluster. This feature is enabled by default on some clusters and must be explicitly enabled on others. You can check if NetworkPolicy is available by running the command kubectl api-versions | grep networking

Also, you need to ensure that the pods that you want to allow traffic to and from are running on the same namespace.

ssh ckad00025

You need to expose the existing app “web-app” externally at:

Host: external.sterling-bengal.local

Path: / (and anything starting with /) → route to web-app

In CKAD labs, this is almost always done with an Ingress pointing to the Service web-app.

1) Find where web-app Service lives (namespace + port)

kubectl get svc -A | grep -w web-app

You’ll get something like:

web-app ClusterIP ... /TCP

Set the namespace:

NS=

Check the service port(s):

kubectl -n $NS get svc web-app -o yaml

Note the service port number (commonly 80).

Also verify it has endpoints (so it actually routes to pods):

kubectl -n $NS get endpoints web-app -o wide

If endpoints are empty, the Service selector doesn’t match pods — tell me and I’ll give the exact fix. But usually it’s fine.

2) Create the Ingress to route / to web-app

Create a manifest (use the service port you saw; I’ll assume 80 below):

cat <<'EOF' > web-app-ingress.yaml

apiVersion: networking.k8s.io/v1

kind: Ingress

metadata:

name: web-app-ingress

spec:

rules:

- host: external.sterling-bengal.local

http:

paths:

- path: /

pathType: Prefix

backend:

service:

name: web-app

port:

number: 80

EOF

Apply it:

kubectl -n $NS apply -f web-app-ingress.yaml

Verify:

kubectl -n $NS get ingress web-app-ingress

kubectl -n $NS describe ingress web-app-ingress

If your Service port is not 80, change number: 80 to the correct value and re-apply.

3) Test external reachability (as instructed)

Run exactly:

curl -i http://external.sterling-bengal.local/

If curl still fails (quick checks)

A) Is there an ingress controller running?

kubectl get pods -A | egrep -i 'ingress|nginx'

kubectl get svc -A | egrep -i 'ingress|nginx'

B) Does Ingress show an address?

kubectl -n $NS get ingress web-app-ingress -o wide

C) Do we have endpoints?

kubectl -n $NS get endpoints web-app -o wide

Solution: