Kubectl configuration for GKE in GCP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is kubectl used for in GKE?

kubectl is a command-line tool that lets you communicate with your Kubernetes cluster on GKE. You use it to deploy applications, inspect resources, and manage the cluster.

beginner

How do you configure kubectl to connect to a GKE cluster?

You run the command gcloud container clusters get-credentials [CLUSTER_NAME] --zone [ZONE] --project [PROJECT_ID]. This updates your local kubeconfig file with the cluster's access info.

beginner

What is the kubeconfig file?

The kubeconfig file stores information about clusters, users, and contexts. It tells kubectl how to connect to your Kubernetes clusters.

beginner

Why do you need to specify the project and zone when configuring kubectl for GKE?

Because GKE clusters are created in specific Google Cloud projects and zones. Specifying these tells gcloud which cluster to get credentials for.

beginner

What command checks if kubectl is properly configured to talk to your GKE cluster?

Use kubectl get nodes. If it returns a list of nodes, your configuration works and you are connected to the cluster.

Which command updates your local kubectl configuration to connect to a GKE cluster?

A kubectl config set-context [CONTEXT_NAME]

B kubectl apply -f cluster.yaml

C gcloud auth login

D gcloud container clusters get-credentials [CLUSTER_NAME] --zone [ZONE] --project [PROJECT_ID]

The gcloud container clusters get-credentials command fetches cluster info and updates your kubeconfig file for kubectl.

What does the kubeconfig file contain?

A Cluster, user, and context information for kubectl

B Source code of your applications

C Google Cloud billing details

D Docker container images

The kubeconfig file stores connection details so kubectl knows how to reach your Kubernetes clusters.

If you run kubectl get nodes and see a list of nodes, what does it mean?

A kubectl is connected to the cluster successfully

B Your cluster is empty

C kubectl is not configured

D You need to restart your computer

Seeing nodes means kubectl can communicate with the cluster and retrieve information.

Why must you specify the project ID when configuring kubectl for GKE?

A To set your billing account

B Because clusters belong to specific Google Cloud projects

C To create a new cluster

D To install kubectl

Clusters are organized under projects, so specifying the project tells gcloud which cluster to access.

Which tool do you use to configure kubectl for GKE?

A terraform

B docker

C gcloud

D helm

The gcloud command-line tool manages Google Cloud resources and configures kubectl for GKE.

Explain the steps to configure kubectl to connect to a GKE cluster.

Think about how you tell kubectl where your cluster lives and how to access it.

Describe the role of the kubeconfig file in kubectl configuration for GKE.

It's like an address book for kubectl.

Practice

1. What is the main purpose of running gcloud container clusters get-credentials when working with GKE?

easy

A. To create a new Kubernetes cluster in GKE

B. To delete an existing GKE cluster

C. To configure kubectl to connect to a specific GKE cluster

D. To update the Kubernetes version of a cluster

Solution

1. Step 1: Understand the command's role

   The command gcloud container clusters get-credentials fetches cluster access credentials and updates the local kubectl config.

2. Step 2: Connect kubectl to the cluster

   This allows kubectl to communicate with the specified GKE cluster for managing resources.

3. Final Answer:

   To configure kubectl to connect to a specific GKE cluster -> Option C

4. Quick Check:

   Get credentials = Setup kubectl connection [OK]

Hint: Remember: get-credentials sets kubectl access [OK]

Common Mistakes:

• Thinking it creates or deletes clusters
• Confusing it with cluster upgrade commands
• Assuming it manages Kubernetes resources directly

2. Which of the following is the correct syntax to configure kubectl for a GKE cluster named my-cluster in zone us-central1-a?

easy

A. gcloud container clusters get-credentials my-cluster --zone us-central1-a

B. kubectl config set-cluster my-cluster --zone us-central1-a

C. gcloud container clusters create my-cluster --zone us-central1-a

D. kubectl get credentials my-cluster --zone us-central1-a

Solution

1. Step 1: Identify the correct command for fetching credentials

   The correct command to configure kubectl is gcloud container clusters get-credentials followed by the cluster name and zone.

2. Step 2: Verify syntax correctness

   gcloud container clusters get-credentials my-cluster --zone us-central1-a matches the correct syntax exactly, while others either use wrong commands or incorrect flags.

3. Final Answer:

   gcloud container clusters get-credentials my-cluster --zone us-central1-a -> Option A

4. Quick Check:

   Correct syntax uses gcloud get-credentials [OK]

Hint: Use gcloud get-credentials with cluster name and zone [OK]

Common Mistakes:

• Using kubectl commands instead of gcloud for credentials
• Mixing create and get-credentials commands
• Omitting the --zone flag or using wrong flags

3. After running gcloud container clusters get-credentials my-cluster --zone us-central1-a, what will be the output of kubectl config current-context?

medium

A. gcloud-context

B. my-cluster-context

C. default

D. gke_project_us-central1-a_my-cluster

Solution

1. Step 1: Understand how get-credentials sets context

   The command sets the current context to the GKE cluster with a name format: gke_PROJECT_ZONE_CLUSTER.

2. Step 2: Match the expected context format

   Given the cluster name and zone, the context will be like gke_project_us-central1-a_my-cluster, where 'project' is your GCP project ID placeholder.

3. Final Answer:

   gke_project_us-central1-a_my-cluster -> Option D

4. Quick Check:

   Current context = gke_project_zone_cluster [OK]

Hint: Current context matches gke_project_zone_cluster format [OK]

Common Mistakes:

• Expecting a simple cluster name as context
• Assuming 'default' context after get-credentials
• Confusing context with namespace or config name

4. You ran gcloud container clusters get-credentials my-cluster --zone us-central1-a but get the error: ERROR: (gcloud.container.clusters.get-credentials) ResponseError: code=404, message=Not found. What is the most likely cause?

medium

A. Your Kubernetes config file is corrupted

B. The cluster name or zone is incorrect or the cluster does not exist

C. You need to update your gcloud SDK version

D. kubectl is not installed on your machine

Solution

1. Step 1: Analyze the 404 Not Found error

   This error means the requested cluster resource was not found in the specified zone or project.

2. Step 2: Check cluster name and zone correctness

   Most likely, the cluster name or zone is wrong, or the cluster was deleted or never created.

3. Final Answer:

   The cluster name or zone is incorrect or the cluster does not exist -> Option B

4. Quick Check:

   404 error = cluster not found [OK]

Hint: 404 means cluster not found; check name and zone [OK]

Common Mistakes:

• Assuming kubectl installation causes this error
• Ignoring the zone or project mismatch
• Thinking SDK update fixes resource not found

5. You want to switch kubectl to manage a different GKE cluster named prod-cluster in zone europe-west1-b. Which sequence of commands correctly updates your kubectl configuration?

hard

A. Run gcloud container clusters get-credentials prod-cluster --zone europe-west1-b then use kubectl config use-context with the new context

B. Run kubectl config set-cluster prod-cluster --zone europe-west1-b only

C. Run gcloud container clusters create prod-cluster --zone europe-west1-b then kubectl config use-context

D. Run kubectl config use-context prod-cluster directly without other commands

Solution

1. Step 1: Fetch credentials for the new cluster

   Use gcloud container clusters get-credentials with the cluster name and zone to update kubectl config with new cluster info.

2. Step 2: Switch kubectl context to the new cluster

   After fetching credentials, use kubectl config use-context with the new context name to switch active cluster.

3. Final Answer:

   Run gcloud get-credentials then kubectl use-context -> Option A

4. Quick Check:

   Get credentials + use-context = switch cluster [OK]

Hint: Always get credentials before switching context [OK]

Common Mistakes:

• Trying to set cluster with kubectl only
• Creating cluster instead of switching
• Using use-context without fetching credentials