POD Design - Labels, Selectors, Annotations

Question 1

How can you select pods with a certain label?

Answer 1

kubectl get pods –selector app=App1,…

Question 2

How do Kubernetes Objects use Labels and Selectors?

Answer 2

• to connect objects internally
• like ReplicaSet that controls pods with a certain label

Question 3

For what are Annotations used and what are they?

Answer 3

• used to record other data for information purposes
• like buildVersion

Question 4

How do we define annotations?

Answer 4

With the metadata in a yaml.
Below name and labels
~~~
metadata:
name:
labels:
annotations:
buildVersion: 1.34
~~~

Question 5

How can you search for multiple labels?

Answer 5

kubectl get pods -lapp=guestbook,role=replica

Question 6

How can you count the numbers of result lines for a command?

Answer 6

kubectl get pods –selector env=dev –no-headers | wc -l

(wc = word count)