kubectl get for listing resources in Kubernetes - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Output of kubectl get pods with label filter

What is the output of the command kubectl get pods -l app=web if the cluster has three pods: web-1 (Running), web-2 (Pending), and db-1 (Running)?

Kubernetes

kubectl get pods -l app=web

A

NAME   READY   STATUS    RESTARTS   AGE
web-1  1/1     Running   0          5m
web-2  0/1     Pending   0          2m

B

NAME   READY   STATUS    RESTARTS   AGE
db-1   1/1     Running   0          10m

C

NAME   READY   STATUS    RESTARTS   AGE
web-1  1/1     Running   0          5m
db-1   1/1     Running   0          10m

D No resources found.

💡 Hint

The label selector -l app=web filters pods with label app=web only.

The command lists pods with label app=web. Only web-1 and web-2 match. db-1 is excluded.

🧠 Conceptual

intermediate

Understanding kubectl get resource types

Which resource type will kubectl get svc list in a Kubernetes cluster?

A Pods

B Services

C Deployments

D Nodes

💡 Hint

The abbreviation svc stands for a common Kubernetes resource that exposes an application.

svc is short for Services, which expose pods to network traffic.

❓ Troubleshoot

advanced

Troubleshooting kubectl get with namespace option

You run kubectl get pods --namespace=dev but get the error: error: the server doesn't have a resource type "pods". What is the most likely cause?

A The cluster does not have any pods in the 'dev' namespace.

B The namespace 'dev' does not exist in the cluster.

C The kubectl version is incompatible with the cluster API.

D The kubectl command is missing the resource type before the namespace flag.

💡 Hint

Check the command syntax and order of arguments.

The error occurs because the resource type 'pods' is not specified before the namespace flag. The correct command is kubectl get pods --namespace=dev or kubectl get pods -n dev.

🔀 Workflow

advanced

Correct order to list all resources in all namespaces

Which command correctly lists all pods in all namespaces with wide output showing node names?

A kubectl get pods -A -o wide

B kubectl get pods -o wide --all-namespaces

C kubectl get pods -A --output=wide

D kubectl get pods --all-namespaces -o wide

💡 Hint

Short flags can be combined and order matters for readability.

Option A uses the short flag -A for all namespaces and -o wide for detailed output. This is the most common and correct usage.

✅ Best Practice

expert

Choosing the best kubectl get command for resource monitoring

You want to monitor the status of all deployments in the 'production' namespace, refreshing every 5 seconds. Which command is best?

A kubectl get deployments -n production --watch --watch-interval=5s

B kubectl get deployments -n production --watch -w 5

C kubectl get deployments -n production --watch --interval=5

D kubectl get deployments -n production --watch-only --interval=5s

💡 Hint

Check the official kubectl flags for watching resources.

The --watch flag enables live updates. The --interval flag sets the refresh rate in seconds. Option C uses correct flags and syntax.

Practice

1. What does the command kubectl get pods do in Kubernetes?

easy

A. Lists all pods in the current namespace

B. Deletes all pods in the cluster

C. Creates a new pod

D. Shows logs of a pod

Solution

1. Step 1: Understand the command structure

   kubectl get is used to list resources, and pods specifies the resource type.

2. Step 2: Interpret the command effect

   The command lists all pods in the current namespace without modifying or deleting anything.

3. Final Answer:

   Lists all pods in the current namespace -> Option A

4. Quick Check:

   kubectl get pods lists pods [OK]

Hint: Remember: 'get' means list resources, not delete or create [OK]

Common Mistakes:

• Confusing 'get' with 'delete' or 'create'
• Thinking it shows logs instead of listing
• Assuming it lists resources cluster-wide by default

2. Which of the following is the correct syntax to list all services in all namespaces using kubectl?

easy

A. kubectl get services -a

B. kubectl get services --all-namespaces

C. kubectl list services --all

D. kubectl show services --all-namespaces

Solution

1. Step 1: Identify the correct command to list services

   kubectl get services is the correct base command to list services.

2. Step 2: Use the correct flag for all namespaces

   The flag --all-namespaces lists resources across all namespaces; -a is not valid here.

3. Final Answer:

   kubectl get services --all-namespaces -> Option B

4. Quick Check:

   Use --all-namespaces to list across namespaces [OK]

Hint: Use full flag --all-namespaces, not short or wrong ones [OK]

Common Mistakes:

• Using incorrect short flag '-a' which is invalid
• Using 'list' or 'show' instead of 'get'
• Forgetting to specify namespaces flag for cluster-wide listing

3. What will be the output of the command kubectl get pods mypod -o wide if mypod exists in the current namespace?

medium

A. An error saying pod not found

B. Only the pod name will be shown

C. Logs of the pod will be displayed

D. Detailed information about the pod including node and IP

Solution

1. Step 1: Understand the command and flags

   kubectl get pods mypod fetches the pod named 'mypod'. The -o wide flag adds extra details like node name and IP.

2. Step 2: Predict the output

   The output will show the pod's name, status, node, IP, and other extended info, not just the name or logs.

3. Final Answer:

   Detailed information about the pod including node and IP -> Option D

4. Quick Check:

   -o wide shows extra pod details [OK]

Hint: Use -o wide to get more pod details in output [OK]

Common Mistakes:

• Expecting only pod name without details
• Confusing output with logs
• Assuming error if pod exists

4. You run kubectl get pod mypod but get the error: error: the server doesn't have a resource type "pod". What is the likely cause?

medium

A. You typed 'pod' instead of 'pods' for resource type

B. The pod 'mypod' does not exist

C. You need to add --all-namespaces flag

D. kubectl is not installed

Solution

1. Step 1: Analyze the error message

   The error says the server doesn't recognize resource type 'pod'. Kubernetes resource types are plural, e.g., 'pods'.

2. Step 2: Identify the syntax mistake

   The command should use pods not pod. This causes the server to reject the request.

3. Final Answer:

   You typed 'pod' instead of 'pods' for resource type -> Option A

4. Quick Check:

   Resource types are plural like 'pods' [OK]

Hint: Always use plural resource names like 'pods', 'services' [OK]

Common Mistakes:

• Using singular resource names
• Assuming pod doesn't exist causes this error
• Thinking missing flag causes resource type error

5. You want to list all deployments in the namespace 'production' with their labels shown. Which command achieves this?

hard

A. kubectl list deployments -namespace production -labels

B. kubectl get deployment production --labels

C. kubectl get deployments -n production --show-labels

D. kubectl get deployments --namespace=production -o labels

Solution

1. Step 1: Specify the resource and namespace correctly

   kubectl get deployments lists deployments; -n production sets the namespace.

2. Step 2: Use the correct flag to show labels

   The flag --show-labels adds labels column to the output. Other options use incorrect flags or syntax.

3. Final Answer:

   kubectl get deployments -n production --show-labels -> Option C

4. Quick Check:

   Use -n for namespace and --show-labels to display labels [OK]

Hint: Use -n for namespace and --show-labels to see labels [OK]

Common Mistakes:

• Using singular 'deployment' instead of 'deployments'
• Wrong flags like '--labels' or '-labels'
• Using 'list' instead of 'get'