What is Kubernetes - Practice Questions & Exercises

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the primary purpose of Kubernetes?

Kubernetes is a popular tool in DevOps. What is its main job?

A It is a tool for designing user interfaces.

B It is a programming language used to write cloud apps.

C It manages and runs containers across many computers automatically.

D It is a database system for storing app data.

💡 Hint

Think about how apps run in many small parts called containers.

Kubernetes helps run and manage containers on many machines, making apps reliable and easy to scale.

💻 Command Output

intermediate

What does the command 'kubectl get pods' show?

When you run kubectl get pods, what information do you get?

A A list of running containers (pods) in the current Kubernetes cluster.

B The current version of Kubernetes installed.

C The logs of a specific container.

D The configuration files of the cluster.

💡 Hint

Pods are the smallest units that run containers in Kubernetes.

The command lists all pods, which are groups of containers running in the cluster.

🔀 Workflow

advanced

Order the steps to deploy an app on Kubernetes

Put these steps in the correct order to deploy an app on Kubernetes.

A 1,2,3,4

B 2,1,3,4

C 1,3,2,4

D 1,2,4,3

💡 Hint

Think about writing config first, then applying it, checking status, and finally exposing.

You first write the deployment file, then apply it to create resources, check pods, and expose the app.

❓ Troubleshoot

advanced

What error occurs if a pod's container image is not found?

You deploy a pod but it never starts. The image name is wrong. What error will Kubernetes show?

A PodEvicted

B ImagePullBackOff

C CrashLoopBackOff

D NodeNotReady

💡 Hint

Think about errors related to pulling container images.

ImagePullBackOff means Kubernetes tried but failed to download the container image.

✅ Best Practice

expert

Which practice helps ensure high availability in Kubernetes?

To keep your app always running even if some pods fail, what should you do?

A Deploy pods only on one node to simplify management.

B Use a single pod with a large resource limit.

C Manually restart pods when they fail.

D Run multiple replicas of your pods using a Deployment.

💡 Hint

Think about spreading risk by having copies of your app running.

Running multiple replicas ensures if one pod fails, others keep serving the app.

Practice

1. What is the main purpose of Kubernetes?

easy

A. To design websites with HTML and CSS

B. To manage and run many copies of programs across multiple computers

C. To write code for mobile applications

D. To create databases for storing data

Solution

1. Step 1: Understand Kubernetes role

   Kubernetes is a tool that helps run many copies of programs on many computers.

2. Step 2: Compare options

   Only To manage and run many copies of programs across multiple computers describes managing programs across computers, which matches Kubernetes' purpose.

3. Final Answer:

   To manage and run many copies of programs across multiple computers -> Option B

4. Quick Check:

   Kubernetes = Manage many program copies [OK]

Hint: Kubernetes manages many program copies on many computers [OK]

Common Mistakes:

• Confusing Kubernetes with programming languages
• Thinking Kubernetes is for website design
• Mixing Kubernetes with database creation

2. Which command is used to interact with Kubernetes from the command line?

easy

A. kubectl

B. docker

C. git

D. npm

Solution

1. Step 1: Identify Kubernetes command-line tool

   The tool to control Kubernetes is called kubectl.

2. Step 2: Check other options

   Docker manages containers, git manages code versions, npm manages JavaScript packages, so they are not correct.

3. Final Answer:

   kubectl -> Option A

4. Quick Check:

   Kubernetes CLI = kubectl [OK]

Hint: Use kubectl to control Kubernetes from terminal [OK]

Common Mistakes:

• Using docker instead of kubectl for Kubernetes
• Confusing git with Kubernetes commands
• Thinking npm controls Kubernetes

3. What happens if a program managed by Kubernetes crashes on one computer?

medium

A. Kubernetes deletes all copies of the program

B. The program stays crashed and Kubernetes does nothing

C. Kubernetes automatically restarts the program on the same or another computer

D. You must manually restart the program yourself

Solution

1. Step 1: Understand Kubernetes fault handling

   Kubernetes watches programs and restarts them automatically if they crash.

2. Step 2: Evaluate options

   Only Kubernetes automatically restarts the program on the same or another computer describes automatic restart, which matches Kubernetes behavior.

3. Final Answer:

   Kubernetes automatically restarts the program on the same or another computer -> Option C

4. Quick Check:

   Kubernetes auto-restarts crashed programs [OK]

Hint: Kubernetes auto-restarts crashed programs [OK]

Common Mistakes:

• Thinking Kubernetes ignores crashed programs
• Believing Kubernetes deletes programs on crash
• Assuming manual restart is always needed

4. You run kubectl get pods but get an error saying "connection refused". What is the likely problem?

medium

A. Kubernetes cluster is not running or unreachable

B. The kubectl command is misspelled

C. Your computer has no internet connection

D. You typed the wrong pod name

Solution

1. Step 1: Analyze error message

   "Connection refused" means kubectl cannot reach the Kubernetes cluster.

2. Step 2: Check options

   Misspelling would cause command not found, no internet is unrelated if cluster is local, wrong pod name gives different error.

3. Final Answer:

   Kubernetes cluster is not running or unreachable -> Option A

4. Quick Check:

   Connection refused = cluster unreachable [OK]

Hint: Connection refused means cluster is down or unreachable [OK]

Common Mistakes:

• Assuming internet is required for local cluster
• Thinking typo causes connection refused
• Confusing pod name errors with connection errors

5. You want to keep a program running with 3 copies at all times using Kubernetes. Which Kubernetes object should you create?

hard

A. Namespace

B. Service

C. ConfigMap

D. Deployment

Solution

1. Step 1: Identify object for managing program copies

   A Deployment manages multiple copies (replicas) of a program and keeps them running.

2. Step 2: Review other objects

   Service exposes programs to network, ConfigMap stores config data, Namespace groups resources, none manage replicas.

3. Final Answer:

   Deployment -> Option D

4. Quick Check:

   Multiple copies managed by Deployment [OK]

Hint: Use Deployment to keep multiple program copies running [OK]

Common Mistakes:

• Confusing Service with Deployment
• Using ConfigMap to manage replicas
• Thinking Namespace controls program copies