Chapter 6. Labels and Annotations

Question 1

What are labels ?

Answer 1

Labels provide identifying metadata for objects. These are fundamental qualities of the object that will be used for grouping, viewing, and operating.

Question 2

Command to create labels:

Answer 2

kubectl run alpaca-prod \

• -image=gcr.io/kuar-demo/kuard-amd64:blue \
• -replicas=2 \
• -labels=”ver=1,app=alpaca,env=prod”

Question 3

Command to show labels:

Answer 3

kubectl get deployments –show-labels

Question 4

Command to edit labels:

Answer 4

kubectl label deployments alpaca-test “canary=true”

Question 5

Command to show a label value as a column:

Answer 5

kubectl get deployments -L canary

Question 6

Command to remove a label:

Answer 6

kubectl label deployments alpaca-test “canary-“

Question 7

Command to list pods based on a specific label:

Answer 7

kubectl get pods –selector=”ver=2”

Question 8

Command to specify to selector ( will behave as an AND operation):

Answer 8

kubectl get pods –selector=”app=bandicoot,ver=2”

Question 9

Command to ask if a label is in a set of values:

Answer 9

kubectl get pods –selector=”app in (alpaca,bandicoot)”

Question 10

Command to ask if a label is set at all:

Answer 10

kubectl get deployments –selector=”canary”

Question 11

What are annotations ?

Answer 11

Annotations provide a place to store additional metadata for Kubernetes objects with the sole purpose of assisting tools and libraries.

Question 12

What are labels selectors ?

Answer 12

Label selectors are used to filter Kubernetes objects based on a set of labels.

Question 13

Command to clean all deployments:

Answer 13

kubectl delete deployments –all