Top Google Kubernetes Engine Interview Questions and Answers

Google Kubernetes Engine (GKE) has become the leading solution for deploying and managing containerized applications in the cloud. Its ability to automate infrastructure management and enable high availability makes it a preferred choice for enterprises aiming at digital transformation.

If you are preparing for a job interview related to Google Kubernetes Engine, there are some key concepts and topics you need to be well versed in. This comprehensive guide provides insights into the most commonly asked GKE interview questions that employers use to test candidates’ knowledge and skills.

Whether you are a beginner looking to break into the field or an experienced professional aiming at your next big career move reviewing these interview questions will help take your preparation to the next level. Let’s get started!

What is Google Kubernetes Engine and how does it work?

Google Kubernetes Engine (GKE) is a managed environment for running containerized applications using Google’s infrastructure. It makes Kubernetes easy to deploy manage and scale.

At its core, GKE consists of multiple compute instances grouped into a container cluster. This cluster is managed by a control plane that handles scheduling containers, maintaining desired state, scaling, and upgrades.

The nodes in the cluster run the container workloads. GKE nodes run the Kubernetes kubelet daemon which communicates with the control plane.

Developers can deploy their containerized applications onto the cluster using Kubernetes concepts like Pods, Deployments, and Services. GKE manages the underlying resources and infrastructure seamlessly.

What are the key components and architecture of GKE?

The key components of Google Kubernetes Engine are:

Cluster – The container cluster which includes a control plane and compute instances or nodes.
Control Plane – Manages and monitors the cluster, handles container scheduling/orchestration.Runs on Google’s infrastructure.
Nodes – The VMs that run your containerized applications. Have Kubernetes kubelet agent installed.
Pods – Smallest unit that can be deployed. Encapsulates one or more containers.
Deployments – Declarative way to manage pods. Handles scaling and updates.
Services – Abstraction to expose applications running on pods and load balance traffic.

The architecture consists of the highly available control plane provisioned by Google which manages the lifecycle of containers on nodes distributed across regions and zones.

Developers interact through kubectl CLI or APIs to deploy applications packaged as containers onto the cluster where they are executed by pods on the nodes.

How does Google Kubernetes Engine simplify Kubernetes management?

Google Kubernetes Engine provides a fully managed Kubernetes service that allows you to deploy Kubernetes clusters without having to install, operate and maintain the control plane infrastructure. This vastly simplifies Kubernetes management.

Specifically, GKE handles tasks like:

Provisioning and managing the Kubernetes control plane
Upgrading control plane versions
Tuning and optimizing control plane configuration for reliability and performance
Ensuring high availability of master components
Securing access to the Kubernetes API
Monitoring health of master and node components
Managing node upgrades, autoscaling, auto-repair

So you don’t have to worry about managing Kubernetes infrastructure and instead focus on your applications and workloads.

How does networking work in Google Kubernetes Engine?

Google Kubernetes Engine utilizes VPC-native clusters allowing pods to have the same IP address range and firewall rules as regular Compute Engine VMs.

This enables seamless communication between containers and VMs using VPC features like routes and firewalls.

Kubernetes Services expose pods to internal or external network endpoints and handle load balancing traffic across pods.

The GKE ingress controller manages external HTTP/S traffic routing to services in the cluster.

Additionally, network policies allow granular control over pod-to-pod and pod-to-endpoint communication based on labels and IP addresses.

How do you handle storage in Google Kubernetes Engine?

Google Kubernetes Engine provides multiple storage options for stateful applications:

Local SSDs – Attached SSD storage to nodes for low latency and high throughput
Google Persistent Disks – Network attached block storage with varying performance tiers
Cloud Filestore – Managed NFS for sharing persistent storage
Cloud Storage Buckets – Object storage, ideal for backups, archives, and images
Third-party storage plugins – Integration with NetApp, Dell EMC, Portworx, etc.

Storage can be provisioned as Kubernetes PersistentVolumes and attached to pods using PersistentVolumeClaims. State is retained across pod restarts.

What strategies are used for high availability in GKE?

Google Kubernetes Engine provides high availability for applications through multiple strategies:

Multiple zones – Spreading applications across zones limits impact of zone failures.
Regional or multi-region clusters – Protects from zone outages.
Multiple node pools – Separates control plane and nodes for resiliency.
Autoscaling – Dynamically scales pods and nodes based on demand.
Auto-healing – Restarts failed containers and replaces unresponsive nodes.
Rolling updates – Incrementally updates deployments with zero downtime.
Cluster autoscaling – Automatically adds/removes nodes based on resource needs.
Stackdriver monitoring – Enables identifying and resolving issues early.

How is security implemented in Google Kubernetes Engine?

Google Kubernetes Engine provides robust security capabilities out of the box:

Private clusters – Nodes and control plane have private IPs only.
Network policies – Isolate pods based on labels and IP addresses.
Cloud IAM – Manage user/service account permissions at project and cluster level.
Pod security policies – Restrict pod permissions based on security standards.
Workload identity – Map Kubernetes service accounts to Google service accounts.
Binary authorization – Ensure only trusted container images are deployed.
Shielded nodes – Nodes boot with verified firmware/kernels to prevent tampering.
Cloud Armor – Ingress DDoS protection and WAF.

How does Node Auto-Provisioning work in GKE?

GKE Node Auto-Provisioning allows cluster nodes to be automatically created and managed based on resource needs.

To enable it, you define an autoscaling profile including the machine types, minimum/maximum nodes, provisioning limits etc.

The Kubernetes cluster autoscaler monitors pod resource requests and node utilization. When additional resources are required, it requests GKE to deploy new nodes matching the profile up to the maximum.

When nodes are underutilized for an extended period, the autoscaler removes them to optimize costs. This provides a hands-off approach to managing node pools.

How can you implement CI/CD workflows for GKE applications?

Here are some ways to implement CI/CD for GKE applications:

Use Jenkins and install plugins like Kubernetes Continuous Deploy.
Create Jenkins pipeline with stages for building, testing, and deploying your app.
Integrate your repo to trigger pipeline runs when code changes.
Build Docker images and push them to Container Registry in build stage.
Run tests against newly built images in the test stage.
Use Kubernetes deployments to rollout new images.
Perform canary or blue-green deployments to reduce risk.
Add monitoring/alerting to detect problems with new versions.
Leverage managed CI/CD platforms like Codefresh, CircleCI etc.

How does Kubernetes handle sensitive data and secrets management?

Kubernetes provides multiple options for managing sensitive data:

Secrets – Encrypt sensitive data like passwords at rest. Stored securely in etcd.
ConfigMaps – Decouple configurations from container images.
Volume mounts – Expose secrets/config data to pods via volumes.
Third party tools – Integrate secret stores like HashiCorp Vault for advanced capabilities.
Google Cloud KMS – Encrypt secrets before storing in Kubernetes.
IAM Roles – Restrict access to sensitive data only to authorized pods/users.
Auditing – Record all access requests to etcd and secrets.

How can you optimize GKE costs and resource usage?

Some ways to optimize GKE costs include:

Choose preemptible VMs for non-critical workloads.
Enable auto-scaling of nodes and pods to meet demand.
Use node auto-provisioning to automatically rightsizing node pools.
Choose machine types based on workload requirements.
Delete unused resources like old deployments, stale nodes.
Analyze usage patterns and adjust cluster sizing accordingly.
Use vertical pod autoscaling to optimize resource limits.
Adopt serverless options like Cloud Run for event-driven apps.
Purchase committed use discounts and utilize them fully.
Use Cloud Monitoring to identify underutilized or overprovisioned resources.

How can you migrate applications from on-prem or other platforms to GKE?

Here is a high-level approach:

2 What is minikube?

Minikube is a software that helps the user to run Kubernetes. It runs on the single nodes that are inside VM on your computer. This tool is also used by programmers who are developing an application using Kubernetes.

4 What are the objectives of the replication controller?

The objectives of the replication controller are:

It is responsible for controlling and administering the pod lifecycle.
It checks to see if the maximum number of replicas are running or not.
The user can check the status of the pods with the help of the replication controller.
It enables to alter a pod. The user can move it around to where they want it.

Kubernetes Interview Questions | DevOps Interview Questions | Kubernetes Scenario Based Questions

FAQ

What is Kubernetes in DevOps interview questions?

Kubernetes, also known as K8s, is a container orchestration platform for managing containerized workloads and services. It allocates application workloads across the Kubernetes cluster and automates container networking needs.

Can pods never be automatically destroyed?

Pod lifetime In general, Pods do not disappear until someone destroys them. This might be a human or a controller. The only exception to this rule is that Pods with a phase of Succeeded or Failed for more than some duration (determined by the master) will expire and be automatically destroyed.

How do you explain Kubernetes architecture in an interview?

The Kubernetes Architecture has mainly 2 components – the master node and the worker node. As you can see in the below diagram, the master and the worker nodes have many inbuilt components within them. The master node has the kube-controller-manager, kube-apiserver, kube-scheduler, etcd.

What’s the difference between Docker and Kubernetes?

While Docker is a container runtime, Kubernetes is a platform for running and managing containers from many container runtimes. Kubernetes supports numerous container runtimes including Docker, containerd, CRI-O, and any implementation of the Kubernetes CRI (Container Runtime Interface).

What questions do you need to know about Kubernetes?

Basic Kubernetes Interview Questions This section of questions will consist of all those basic questions that you need to know related to the working of Kubernetes. Q1. How is Kubernetes different from Docker Swarm? Setup is very complicated, but once installed cluster is robust. Installation is very simple, but the cluster is not robust.

What should a Kubernetes interviewer expect?

In this Kubernetes interview question, the interviewer would expect a thorough explanation. You can explain what it is and also it has been useful to you (if you have used it in your work so far!). A Heapster is a performance monitoring and metrics collection system for data collected by the Kublet.

How do you prepare for a Kubernetes interview?

Since Kubernetes is commonly used by professionals in these positions, hiring managers want to get a sense of your knowledge and experience with Kubernetes to ensure you’ll be successful in the role. One of the best ways to prepare for challenging interview questions is to set up a mock interview.

How long does it take to hire a Kubernetes developer?

Hire top vetted developers within 4 days. The above-mentioned Kubernetes technical interview questions will help the candidates improve their interview preparation. It will also help recruiters weigh the candidate’s skills appropriately.