Kubernetes Components explained

Question 1

A Node is a simple server it can be a

Answer 1

physical or a virtual machine that has the resources to run containers and pods

Question 2

Pod is an abstraction over a container it creates

Answer 2

a running environment or a
layer on top of the container, e.g. Docker container. 🐳

Question 3

Why does Kubernetes abstract away the container runtime or container
technologies?

Answer 3

So you don’t have to work directly with Docker or whatever container technology you use in Kubernetes. can easily replace them if you want to without making
changes to the existing Kubernetes configuration.

Question 4

How does the virtual network inside of Kubernetes facilitate communication inside the cluster?

Answer 4

Each Pod gets its own IP address. They communicate using that IP address, which is a cluster internal IP address.

Question 5

Why are Pods considered to be ephemeral?

Answer 5

They die very easily ☠ This can happen when the server runs out of resources, the
application crashes or the server gets restarted.

Question 5

Why are Pods considered to be ephemeral?

Answer 5

They die very easily ☠ This can happen when the server runs out of resources, the
application crashes or the server gets restarted.

Question 6

To make your application accessible through a browser you need to create an

Answer 6

External Service
Which is a Service that makes the application accessible from external clients, like a browser.

Question 7

Ingress is the entry

Answer 7

point to your Kubernetes cluster. So, instead of a Service,
the request goes first to Ingress, which forwards it to the Service.

Question 8

ConfigMap is an

Answer 8

external configuration for your application.

Question 9

ConfigMap usually contains configuration data like

Answer 9

URLs of databases or some other Services that your application uses.

Question 10

You create a ConfigMap _________________ of the pod and then pass it to the pod on
startup

Answer 10

independently

Question 11

What is the process of changing the name of a service endpoint with and without configMap?

Answer 11

Now, if you change the name of the service endpoint, you just adjust the
ConfigMap, restart the pod and that’s it. 😎 You don’t have to rebuild an image and
go through this whole cycle.

Question 12

Secret’s is another Kubernetes component just like ConfigMap, but the difference is
that it’s used to store

Answer 12

secret data, like credentials or certificates. It’s stored in base64 encoded format

Question 12

Secret’s is another Kubernetes component just like ConfigMap, but the difference is
that it’s used to store

Answer 12

secret data, like credentials or certificates. It’s stored in base64 encoded format

Question 13

You can use the data from ConfigMap or Secret inside your application Pod as

Answer 13

environmental variables or as a properties file.

Question 14

The Secret component has built-in mechanisms like

Answer 14

encryption, defining authorization policies
Not enabled by default

Question 15

What happens to data when a pod dies?

Answer 15

Kubernetes doesn’t provide data persistence out of the box. So the data is lost

Question 16

The Volume component attaches a

Answer 16

physical storage on a hard drive to your Pod

Question 17

The Volume storage location could be (3)

Answer 17

on a local server on-premises
on the same server Node where the Pod is running
or it could be on a remote cloud server

Question 18

Kubernetes explicitly doesn’t manage any data persistence a Kubernetes user or an administrator is responsible for (3)

Answer 18

backing up the data
replicating the data
and managing it to ensure it’s kept on proper hardware

Question 19

If you need to update the docker image for “my-app” what is the most efficient way to get this done without manually updating each pod?

Answer 19

You update it in the deployment, and deployment will then automatically update and restart all running pods.

Question 20

A pod is a layer of _______________ on top of containers and _______________ is another
abstraction on top of _______,

Answer 20

abstraction
Deployment
Pods

Question 21

Services are used to communicate

Answer 21

between the Pods