CKS Online Practice Questions and Answers

Correct Answer: A

master1 $ k get pods -n test --show-labels uk.co.certification.simulator.questionpool.PList@132b47c0 $ vim netpol.yaml uk.co.certification.simulator.questionpool.PList@132b4af0 master1 $ k apply -f netpol.yaml

controlplane $ k get pods -n test --show-labels NAME READY STATUS RESTARTS AGE LABELS test-pod 1/1 Running 0 34s role=test,run=test-pod testing 1/1 Running 0 17d run=testing master1 $ vim netpol1.yaml apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: deny-network namespace: test spec: podSelector: {} policyTypes:

-Ingress

-Egress

Correct Answer: A

Correct Answer: A

Correct Answer: A

Correct Answer: A

Create a PSP that will prevent the creation of privileged pods in the namespace. $ cat clusterrole-use-privileged.yaml apiVersion: rbac.authorization.k8s.io/v1

kind: ClusterRole metadata: name: use-privileged-psp rules:

-apiGroups: ['policy']

resources: ['podsecuritypolicies']

verbs: ['use']

resourceNames:

-default-psp

apiVersion: rbac.authorization.k8s.io/v1 kind: RoleBinding metadata: name: privileged-role-bind namespace: psp-test roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: use-privileged-psp subjects:

-kind: ServiceAccount name: privileged-sa $ kubectl -n psp-test apply -f clusterrole-use-privileged.yaml

After a few moments, the privileged Pod should be created.

Create a new PodSecurityPolicy named prevent-privileged-policy which prevents the creation of privileged pods.

apiVersion: policy/v1beta1

kind: PodSecurityPolicy

metadata:

name: example

spec:

privileged: false # Don't allow privileged pods!

# The rest fills in some required fields.

seLinux:

rule: RunAsAny

supplementalGroups:

rule: RunAsAny

runAsUser:

rule: RunAsAny

fsGroup:

rule: RunAsAny

volumes:

-'*'

And create it with kubectl:

kubectl-admin create -f example-psp.yaml

Now, as the unprivileged user, try to create a simple pod:

kubectl-user create -f- <

apiVersion: v1

kind: Pod

metadata:

name: pause

spec:

containers:

-name: pause

image: k8s.gcr.io/pause

EOF

The output is similar to this:

Error from server (Forbidden): error when creating "STDIN": pods "pause" is forbidden:

unable to validate against any pod security policy: []

Create a new ServiceAccount named psp-sa in the namespace default.

$ cat clusterrole-use-privileged.yaml

apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRole metadata: name: use-privileged-psp rules:

-apiGroups: ['policy']

resources: ['podsecuritypolicies']

verbs: ['use']

resourceNames:

-default-psp

apiVersion: rbac.authorization.k8s.io/v1 kind: RoleBinding metadata: name: privileged-role-bind namespace: psp-test roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: use-privileged-psp subjects:

-kind: ServiceAccount name: privileged-sa $ kubectl -n psp-test apply -f clusterrole-use-privileged.yaml After a few moments, the privileged Pod should be created.

Create a new ClusterRole named prevent-role, which uses the newly created Pod Security Policy prevent-privileged-policy.

apiVersion: policy/v1beta1

kind: PodSecurityPolicy

metadata:

name: example

spec:

privileged: false # Don't allow privileged pods!

# The rest fills in some required fields.

seLinux:

rule: RunAsAny

supplementalGroups:

rule: RunAsAny

runAsUser:

rule: RunAsAny

fsGroup:

rule: RunAsAny

volumes:

-'*'

And create it with kubectl:

kubectl-admin create -f example-psp.yaml

Now, as the unprivileged user, try to create a simple pod:

kubectl-user create -f- <

apiVersion: v1

kind: Pod

metadata:

name: pause

spec:

containers:

-name: pause

image: k8s.gcr.io/pause

EOF

The output is similar to this:

Error from server (Forbidden): error when creating "STDIN": pods "pause" is forbidden:

unable to validate against any pod security policy: []

Create a new ClusterRoleBinding named prevent-role-binding, which binds the created ClusterRole prevent-role to the created SA psp-sa.

apiVersion: rbac.authorization.k8s.io/v1

# This role binding allows "jane" to read pods in the "default" namespace. # You need to already have a Role named "pod-reader" in that namespace.

kind: RoleBinding

metadata:

name: read-pods

namespace: default

subjects:

# You can specify more than one "subject"

-kind: User name: jane # "name" is case sensitive apiGroup: rbac.authorization.k8s.io roleRef: # "roleRef" specifies the binding to a Role / ClusterRole kind: Role #this must be Role or ClusterRole name: pod-reader # this must match the name of the Role or ClusterRole you wish to bind to apiGroup: rbac.authorization.k8s.io

apiVersion: rbac.authorization.k8s.io/v1 kind: Role metadata: namespace: default name: pod-reader rules:

-apiGroups: [""] # "" indicates the core API group resources: ["pods"] verbs: ["get", "watch", "list"]

Correct Answer: A

Correct Answer: A

Correct Answer: A

[desk@cli] $ k create sa backend-qa -n qasa/backend-qa created [desk@cli] $ k get role,rolebinding -n qaNo resources found in qa namespace. [desk@cli] $ k create role backend -n qa --resource pods,namespaces,configmaps --verb list# No access to secret [desk@cli] $ k create rolebinding backend -n qa --role backend --serviceaccount qa:backend-qa [desk@cli] $ vim /home/ cert_masters/frontend-pod.yaml uk.co.certification.simulator.questionpool.PList@120e0660 [desk@cli] $ k apply -f /home/cert_masters/frontend-pod.yamlpod created [desk@cli] $ k create sa backend-qa -n qaserviceaccount/backend-qa created [desk@cli] $ k get role,rolebinding -n qaNo resources found in qa namespace. [desk@cli] $ k create role backend -n qa --resource pods,namespaces,configmaps --verb listrole.rbac.authorization.k8s.io/backend created [desk@cli] $ k create rolebinding backend -n qa --role backend --serviceaccount qa:backendqarolebinding.rbac.authorization.k8s.io/backend created [desk@cli] $ vim /home/cert_masters/frontend-pod.yaml apiVersion: v1 kind: Pod metadata: name: frontend spec: serviceAccountName: backend-qa # Add this image: nginx name: frontend [desk@cli] $ k apply -f /home/cert_masters/frontend-pod.yamlpod/frontend createdhttps://kubernetes.io/docs/tasks/configure-pod-container/configure-service-account/

Correct Answer: A

Correct Answer: A

Create psp to disallow privileged container uk.co.certification.simulator.questionpool.PList@11600d40 k create sa psp-denial-sa -n development uk.co.certification.simulator.questionpool.PList@11601040 namespace: development Explanationmaster1 $ 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 developmentmaster1 $ 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

Correct Answer: A

se kubectl to create a CSR and approve it.

Get the list of CSRs:

kubectl get csr

Approve the CSR:

kubectl certificate approve myuser

Get the certificateRetrieve the certificate from the CSR:

kubectl get csr/myuser -o yaml

here are the role and role-binding to give john permission to create NEW_CRD resource:

kubectl apply -f roleBindingJohn.yaml --as=john

rolebinding.rbac.authorization.k8s.io/john_external-rosource-rb created

kind: RoleBinding

apiVersion: rbac.authorization.k8s.io/v1

metadata:

name: john_crd

namespace: development-john

subjects:

-kind: User name: john apiGroup: rbac.authorization.k8s.io roleRef: kind: ClusterRole name: crd-creation

kind: ClusterRole apiVersion: rbac.authorization.k8s.io/v1 metadata: name: crd-creation rules:

-apiGroups: ["kubernetes-client.io/v1"] resources: ["NEW_CRD"] verbs: ["create, list, get"]

Correct Answer: A

Correct Answer: A

Correct Answer: A

Kubernetes auditing provides a security-relevant chronological set of records about a cluster. Kube-apiserver performs auditing. Each request on each stage of its execution generates an event, which is then pre-processed according to a

certain policy and written to a backend. The policy determines what's recorded and the backends persist the records. You might want to configure the audit log as part of compliance with the CIS (Center for Internet Security) Kubernetes

Benchmark controls.

The audit log can be enabled by default using the following configuration in cluster.yml:

services:

kube-api:

audit_log:

enabled: true

When the audit log is enabled, you should be able to see the default values at /etc/kubernetes/audit-policy.yaml

The log backend writes audit events to a file in JSONlines format. You can configure the log audit backend using the following kube-apiserver flags:

--audit-log-path specifies the log file path that log backend uses to write audit events. Not specifying this flag disables log backend. - means standard out --audit-log-maxage defined the maximum number of days to retain old audit log files

--audit-log-maxbackup defines the maximum number of audit log files to retain

--audit-log-maxsize defines the maximum size in megabytes of the audit log file before it gets rotated

If your cluster's control plane runs the kube-apiserver as a Pod, remember to mount the hostPath to the location of the policy file and log file, so that audit records are persisted.

For example:

--audit-policy-file=/etc/kubernetes/audit-policy.yaml \

--audit-log-path=/var/log/audit.log

Correct Answer: A

ssh-add ~/.ssh/tempprivate eval "$(ssh-agent -s)" cd contrib/terraform/aws vi terraform.tfvars terraform init terraform apply -var-file=credentials.tfvars ansible-playbook -i ./inventory/hosts ./cluster.yml -e ansible_ssh_user=core -e bootstrap_os=coreos -b --become-user=root --flush-cache -e ansible_user=core