Linux Foundation Certified Kubernetes Security Specialist (CKS) : CKS

Correct Answer:

See the Explanation belowExplanation:

Correct Answer:

See the Explanation below for complete solution
Explanation:
Below is the CKS / CKA exam-style, exact step-by-step solution for Upgrading a kubeadm worker node.
Follow in order, type exact commands, no extra actions.
QUESTION - Upgrade node compute-0 (EXAM MODE)
1) Connect to the correct host (control plane)
ssh cks000034
sudo -i
export KUBECONFIG=/etc/kubernetes/admin.conf
2) Identify the control plane Kubernetes version
This is the target version for compute-0.
kubectl get nodes
Example output:
NAME STATUS ROLES VERSION
control-plane Ready control-plane v1.27.4
compute-0 Ready <none> v1.26.6
Note the control-plane version
Example: v1.27.4
3) Drain the compute node (do NOT modify workloads manually)
kubectl drain compute-0 --ignore-daemonsets --delete-emptydir-data
Wait until drain completes successfully.
4) SSH into the compute node
ssh compute-0
sudo -i
5) Check current kubeadm version on compute node
kubeadm version
6) Upgrade kubeadm to match control plane version
Replace 1.27.4 with the exact control-plane version you observed.
apt-get update
apt-get install -y kubeadm=1.27.4-00
Verify:
kubeadm version
7) Run kubeadm upgrade for the node
kubeadm upgrade node
✅ This updates node-specific configs (NO workloads touched).
8) Upgrade kubelet and kubectl to the same version
apt-get install -y kubelet=1.27.4-00 kubectl=1.27.4-00
9) Restart kubelet
systemctl daemon-reload
systemctl restart kubelet
systemctl status kubelet --no-pager
10) Exit the compute node (IMPORTANT)
exit
11) Uncordon the compute node (back on control plane)
kubectl uncordon compute-0
12) Final verification
kubectl get nodes
Expected:
NAME STATUS VERSION
compute-0 Ready v1.27.4

Correct Answer:

See the Explanation belowExplanation:

Correct Answer:

See the Explanation belowExplanation:
$ kubectl get ing -n <namespace-of-ingress-resource>
NAME HOSTS ADDRESS PORTS AGE
cafe-ingress cafe.com 10.0.2.15 80 25s
$ kubectl describe ing <ingress-resource-name> -n <namespace-of-ingress-resource> Name: cafe-ingress Namespace: default Address: 10.0.2.15 Default backend: default-http-backend:80 (172.17.0.5:8080) Rules:
Host Path Backends
---- ---- --------
cafe.com
/tea tea-svc:80 (<none>)
/coffee coffee-svc:80 (<none>)
Annotations:
kubectl.kubernetes.io/last-applied-configuration: {"apiVersion":"networking.k8s.io/v1","kind":"Ingress","metadata":{"annotations":{},"name":"cafe-ingress","namespace":"default","selfLink":"/apis/networking/v1/namespaces/default/ingresses/cafe-ingress"},"spec":{"rules":[{"host":"cafe.com","http":{"paths":[{"backend":{"serviceName":"tea-svc","servicePort":80},"path":"/tea"},{"backend":{"serviceName":"coffee-svc","servicePort":80},"path":"/coffee"}]}}]},"status":{"loadBalancer":{"ingress":[{"ip":"169.48.142.110"}]}}} Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal CREATE 1m ingress-nginx-controller Ingress default/cafe-ingress
Normal UPDATE 58s ingress-nginx-controller Ingress default/cafe-ingress
$ kubectl get pods -n <namespace-of-ingress-controller>
NAME READY STATUS RESTARTS AGE
ingress-nginx-controller-67956bf89d-fv58j 1/1 Running 0 1m
$ kubectl logs -n <namespace> ingress-nginx-controller-67956bf89d-fv58j
------------------------------------------------------------------------------- NGINX Ingress controller Release: 0.14.0 Build: git-734361d Repository: https://github.com/kubernetes/ingress-nginx
-------------------------------------------------------------------------------
....

Correct Answer:

See the Explanation below
Explanation:
$vim /etc/falco/falco_rules.local.yaml
- rule: Container Drift Detected (open+create)
desc: New executable created in a container due to open+create
condition: >
evt.type in (open,openat,creat) and
evt.is_open_exec=true and
container and
not runc_writing_exec_fifo and
not runc_writing_var_lib_docker and
not user_known_container_drift_activities and
evt.rawres>=0
output: >
%evt.time,%user.uid,%proc.name # Add this/Refer falco documentation
priority: ERROR
$kill -1 <PID of falco>
Explanation:
[desk@cli] $ ssh node01
[node01@cli] $ vim /etc/falco/falco_rules.yaml
search for Container Drift Detected & paste in falco_rules.local.yaml
[node01@cli] $ vim /etc/falco/falco_rules.local.yaml
- rule: Container Drift Detected (open+create)
desc: New executable created in a container due to open+create
condition: >
evt.type in (open,openat,creat) and
evt.is_open_exec=true and
container and
not runc_writing_exec_fifo and
not runc_writing_var_lib_docker and
not user_known_container_drift_activities and
evt.rawres>=0
output: >
%evt.time,%user.uid,%proc.name # Add this/Refer falco documentation
priority: ERROR
[node01@cli] $ vim /etc/falco/falco.yaml