Solution (Step by Step) :
1. Create a Network Policy:
- Create a Network Policy that allows access to the web application only from the authorized IP addresses.
- Here's an example network policy:

- Replace '10.0.0.0/24' With the authorized IP addresses you want to allow. - This policy allows outbound traffic to any IP address. - Create the policy using 'kubectl apply -f web-app-allow-list.yaml 2. Create a Network Policy for the Kubernetes API Server: - Create a Network Policy that allows access to the Kubernetes API server from any IP address. - Here's an example network policy:

- Create the policy using 'kubectl apply -f api-server-allow-all.yaml 3. Verify the Network Policies: - Use 'kubectl get networkpolicy -n default' to verify that the 'web-app-allow-list' Network Policy is created and 'kubectl get networkpolicy -n kube- system' to verify that the 'api-server-allow-all' Network Policy is created. 4. Test the Access: - Attempt to access the web application from a machine within the authorized IP address range. You should be able to access the application. - Attempt to access the web application from a machine outside the authorized IP address range. You should be unable to access tne application. 5. Verify API Server Access: - Try to connect to the Kubernetes API server from any machine using 'kubectl'. You should be able to connect successfully. Note: This approach assumes that the web application is running in the 'default' namespace. If it's running in a different namespace, adjust the 'namespaces field in the 'web-app-allow-list' Network Policy accordingly.

Create psp to disallow privileged container
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
name: deny-access-role
rules:
- apiGroups: ['policy']
resources: ['podsecuritypolicies']
verbs: ['use']
resourceNames:
- "deny-policy"
k create sa psp-denial-sa -n development
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: restrict-access-bing
roleRef:
kind: ClusterRole
name: deny-access-role
apiGroup: rbac.authorization.k8s.io
subjects:
- kind: ServiceAccount
name: psp-denial-sa
namespace: development
Explanation
master1 $ vim psp.yaml
apiVersion: policy/v1beta1
kind: PodSecurityPolicy
metadata:
name: deny-policy
spec:
privileged: false # Don't allow privileged pods!
seLinux:
rule: RunAsAny
supplementalGroups:
rule: RunAsAny
runAsUser:
rule: RunAsAny
fsGroup:
rule: RunAsAny
volumes:
- '*'
master1 $ vim cr1.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
name: deny-access-role
rules:
- apiGroups: ['policy']
resources: ['podsecuritypolicies']
verbs: ['use']
resourceNames:
- "deny-policy"
master1 $ k create sa psp-denial-sa -n development master1 $ vim cb1.yaml apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRoleBinding metadata:
name: restrict-access-bing
roleRef:
kind: ClusterRole
name: deny-access-role
apiGroup: rbac.authorization.k8s.io
subjects:
# Authorize specific service accounts:
- kind: ServiceAccount
name: psp-denial-sa
namespace: development
master1 $ k apply -f psp.yaml master1 $ k apply -f cr1.yaml master1 $ k apply -f cb1.yaml Reference: https://kubernetes.io/docs/concepts/policy/pod-security-policy/

See the Explanation below
Explanation:

See the Explanation below for complete solution
Explanation:
1) Connect to the correct host
ssh cks000028
sudo -i
2) Use the right kubeconfig (safe in exam)
export KUBECONFIG=/etc/kubernetes/admin.conf
3) Open the provided Deployment manifest
vi /home/candidate/finer-sunbeam/lamp-deployment.yaml
4) Edit ONLY the Pod template security settings (add/modify these fields) Inside:
spec: -> template: -> spec:
4.1 Set container to run as user 20000
Add (or change) under the container securityContext::
securityContext:
runAsUser: 20000
4.2 Make root filesystem read-only
In the SAME container securityContext: ensure:
readOnlyRootFilesystem: true
4.3 Forbid privilege escalation
In the SAME container securityContext: ensure:
allowPrivilegeEscalation: false
✅ The container section should look like this (example - keep your existing image/ports/etc):
spec:
template:
spec:
containers:
- name: <your-container-name>
image: <unchanged>
securityContext:
runAsUser: 20000
readOnlyRootFilesystem: true
allowPrivilegeEscalation: false
If there are multiple containers, apply the same securityContext to each container.
Save and exit:
:wq
5) Apply the manifest (updates Deployment -> recreates Pods)
kubectl -n lamp apply -f /home/candidate/finer-sunbeam/lamp-deployment.yaml
6) Wait for rollout
kubectl -n lamp rollout status deployment/lamp-deployment
7) Verify the security settings are live
7.1 Check the Pod is running
kubectl -n lamp get pods -l app=lamp -o wide
(if label differs, just kubectl -n lamp get pods)
7.2 Verify the three fields on a running Pod
Pick the Pod name and run:
POD=$(kubectl -n lamp get pods -o jsonpath='{.items[0].metadata.name}') kubectl -n lamp get pod $POD -o jsonpath='{.spec.containers[0].securityContext.runAsUser}{"\n"}{.spec.containers[0].securityContext.readOnlyRootFilesystem}{"\n"}{.spec.containers[0].securityContext.allowPrivilegeEscalation}{"\n"}' Expected output:
20000
true
false
If the pod fails after readOnlyRootFilesystem=true
Don't change the requirement (task demands it). Usually the app needs writable dirs via volumes, but the task doesn't ask for that-so only adjust if the manifest already has volumes and just needs these securityContext fields.