Linux Foundation CKA Quiz 7 Topic 3 Questions 31-35

Question: 1

Create a ETCD backup of kubernetes cluster

Note : You don't need to memorize command, refer -

AETCDCTL_API=3 etcdctl --endpoints=[ENDPOINT] --cacert=[CA CERT]
--cert=[ETCD SERVER CERT] --key=[ETCD SERVER KEY] snapshot save
[BACKUP FILE NAME]
In exam, cluster setup is done with kubeadm , this means ETCD
used by the kubernetes cluster is coming from static pod.
kubectl get pod -n kube-system
kubectl describe pod etcd-master -n kube-system
You can locate the information on
endpoint: --- advertise-client-urls=https://172.17.0.15:2379
ca certificate: --- trusted-cafile=/etc/kubernetes/pki/etcd/ca.crt
server certificate : --- certfile=/etc/kubernetes/pki/etcd/server.crt
key: --- key-file=/etc/kubernetes/pki/etcd/server.key
To Create backup
export ETCDCTL_API=3
(or)
ETCDCTL_API=3 etcdctl ETCDCTL_API=3 etcdctl --
endpoints=https://172.17.0.15:2379 --
cacert=/etc/kubernetes/pki/etcd/ca.crt --
cert=/etc/kubernetes/pki/etcd/server.crt --
key=/etc/kubernetes/pki/etcd/server.key snapshot save etcdsnapshot.db
//Verify
ETCDCTL_API=3 etcdctl --write-out=table snapshot status
snapshot.db

BETCDCTL_API=3 etcdctl --endpoints=[ENDPOINT] --cacert=[CA CERT]
--cert=[ETCD SERVER CERT] --key=[ETCD SERVER KEY] snapshot save
[BACKUP FILE NAME]
In exam, cluster setup is done with kubeadm , this means ETCD
used by the kubernetes cluster is coming from static pod.
kubectl get pod -n kube-system
kubectl describe pod etcd-master -n kube-system
You can locate the information on
endpoint: --- advertise-client-urls=https://172.16.0.18:2379
ca certificate: --- trusted-cafile=/etc/kubernetes/pki/etcd/ca.crt
server certificate : --- certfile=/etc/kubernetes/pki/etcd/server.crt
key: --- key-file=/etc/kubernetes/pki/etcd/server.key
To Create backup
export ETCDCTL_API=3
(or)
ETCDCTL_API=3 etcdctl ETCDCTL_API=3 etcdctl --
endpoints=https://172.17.0.15:2379 --
key=/etc/kubernetes/pki/etcd/server.key snapshot save etcdsnapshot.db
//Verify
ETCDCTL_API=3 etcdctl --write-out=table snapshot status
snapshot.db

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Question: 2

create a pod in a specific node (node1) by placing the pod definition file in a particular folder ''/etc/kubernetes/manifests''.

AGenerate YAML before we SSH to the specific node, then copy the YAML
into the exam notepad to use it after SSH into worker node.
SSH to the node: 'ssh node1'
Gain admin privileges to the node: 'sudo -i'
Move to the manifest-path 'cd /etc/kubernetes/manifests'
kubelet config file -- /var/lib/kubelet/config.yaml
Edit the config file ''vi /var/lib/kubelet/config.yaml'' to add
staticPodPath
staticPodPath: /etc/kubernetes/manifests
Restart the kubelet ''systemctl restart kubelet''

BGenerate YAML before we SSH to the specific node, then copy the YAML
into the exam notepad to use it after SSH into worker node.
SSH to the node: 'ssh node1'
Gain admin privileges to the node: 'sudo -i'
Move to the manifest-path 'cd /etc/kubernetes/manifests'
Place the generated YAML into the folder 'vi nginx.yaml'
Find the kubelet config file path 'ps -aux | grep kubelet' . This
will output information on kubelet process. Locate the kubelet config
file location.
kubelet config file -- /var/lib/kubelet/config.yaml
Edit the config file ''vi /var/lib/kubelet/config.yaml'' to add
staticPodPath
staticPodPath: /etc/kubernetes/manifests
Restart the kubelet ''systemctl restart kubelet''

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Question: 3

Evict all existing pods from a node-1 and make the node unschedulable for new pods.

Akubectl get nodes
kubectl drain node-1 #It will evict pods running on node-1 to
other nodes in the cluster
kubectl cordon node-1 # New pods cannot be scheduled to the
node
// Verify
kubectl get no
When you cordon a node, the status shows ''SchedulingDisabled''

Bkubectl get nodes
kubectl drain node-1 #It will evict pods running on node-1 to
other nodes in the cluster
// Verify
kubectl get no
When you cordon a node, the status shows ''SchedulingDisabled''

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Question: 4

Check nodes which are ready and print it to a file /opt/nodestatus

AJSONPATH='{range .items[*]}{@.metadata.name}:{range
@.status.conditions[*]}{@.type}={@.status};{end}{end}' \
&& kubectl get nodes -o jsonpath='$JSONPATH' | grep
'Ready=True' > /opt/node-status
//Verify
cat /opt/node-status

BJSONPATH='{range .items[*]}{@.metadata.name}:{range
@.status.conditions[*]}{@.type}={@.status};{end}{end}' \
//Verify
cat /opt/node-status

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Question: 5

Install a kubernetes cluster with one master and one worker using kubeadm

AThis is a straightforward question, you need to install kubernetes cluster using kubeadm with one master and one worker.
Refer : https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/

BThis is a straightforward question, you need to install kubernetes cluster using kubeadm with one master and one worker.
Installation is considered success once both master and worker
nodes become available.
Refer : https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/

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Linux Foundation CKA Quiz:7 Topic:3 Questions:31-35