k8s part 2

Question 1

what is a label in k8s?

Answer 1

In Kubernetes (k8s), labels are key-value pairs that you attach to objects, such as pods, nodes, and services. You can label all pods that belong to a specific application or environment

Question 2

what is the command to label a pod ?

Answer 2

kubectl label pod [pod name] key=value

Question 3

what are selectors

Answer 3

Selectors in Kubernetes are used to filter and identify a set of objects based on their labels

Question 4

what is the command to see all pods with labels?

Answer 4

kubectl get pods - - show-labels

Question 5

what is the command to remove a label from a pod ?

Answer 5

kubectl label pod [pod name] key -

Question 6

what are replica sets?

Answer 6

A ReplicaSet ensures that a specified number of identical pods are running at any given time

Question 7

what is the command to generate a pod manifest on the cli?

Answer 7

kubectl run [pod name] - - image=[image name] - - dry-run=client -o yaml

Question 8

what is a deployment ?

Answer 8

A deployment in Kubernetes (k8s) is a way to manage and update applications. If you need to update your app, the deployment ensures the changes are applied smoothly without downtime using replicaset.

Question 9

what are some challenges you face if you just use a replica set?

Answer 9

• Updating your application requires manual changes to the ReplicaSet
• There is no built-in way to revert to a previous version if an update fails.
• ReplicaSets do not support advanced update strategies like rolling update.

Question 10

what are advantages of using a deployment ?

Answer 10

• updates your application, ensuring new versions are rolled out smoothly.
• If an update fails or causes issues, Deployments can easily revert to a previous version.
• Deployments make it easy to scale your application up or down by simply changing the number of replicas
• Ensures that the desired state of your application is consistently maintained across all replicas.
• Automatically replaces failed or crashed pods to maintain the desired number of replicas.
• Keeps a history of previous versions and updates, making it easier to track changes and diagnose issues.

Question 11

what is the command to output a deployment manifest file?

Answer 11

kubectl run deployment [name] –image=[name] - -dry-run=client -o yaml

Question 12

what is the command to create a deployment using cli?

Answer 12

kubectl run deployment my-deployment - -image=nginx

Question 13

what is the command to generate a deployment manifest file via CLI?

Answer 13

kubectl create deployment [name]
- -image=nginx - -dry-run=client -o yaml