Pods, ReplicaSet, Deployments

Question 1

What format of file does Kubernetes use as input for the creation of objects as pod, deployments, services etc?

Answer 1

YAML files

Question 2

What are the 4 top level or root level properties of a Kubernetes definition YAML files? These are also the required fields?

Answer 2

apiVersion:
kind:
metadata:
spec:

Question 3

What is apiVersion in Kubernetes definition YAML files?

Answer 3

Version of the Kubernetes API used to create the object.
eg. v1, apps/v1beta
apiVersion is a single value

Question 4

What is kind property in Kubernetes definition YAML files?

Answer 4

kind refers to the type of object we want to create.
eg. POD, ReplicaSet, Service
kind is also a single value

Question 5

What is metadata in Kubernetes definition YAML files?

Answer 5

metadata is the data about the object, like name, label etc. This in the form of a dictionary. names and labels are children of metadata.
metadata is a dictionary

Question 6

Can you tell about name and label inside metadata property of a Kubernetes definition YAML file?

Answer 6

name is a single value
label is again a dictionary within the metadata dictionary. It can have any key:value pair as you desire

Question 7

what are labels in metadata used for?

Answer 7

label is like a custom dictionary, where you can add name for your app or any custom key:value pair for that object

Question 8

what is spec property in in Kubernetes definition YAML files used for?

Answer 8

Used to provide additional details pertaining to that object including details such as the container image.
spec is a dictionary that contains a list of containers which in turn is a dictionary which contains key value pairs like
spec:
containers:
- name: name of the container
image: image of that container

Question 9

Command to create pod using YAML definition file?

Answer 9

kubectl create -f pod-definition.yml

Question 10

How to see detailed information about a pod?

Answer 10

kubectl describe pod myapp-pod

Question 11

Which command to create a pod?

Answer 11

kubectl apply
or
kubectl create
Both of these can be used

Question 12

How to specify the pod definition file when creating a pod?

Answer 12

kubectl apply -f pod.yaml
or
kubectl create -f pod.yaml

Question 13

Command to check the status of the pod?

Answer 13

kubectl get pods
kubectl describe pod nginx

Question 14

Create a pod definition file for creating nginx pod with some labels and image specified?