This blog post covers a brief overview of the topics covered and some common questions asked on Day 7 and Day 8 Live Interactive training on Docker and Kubernetes Certification i.e. CKA / CKAD .
In the Day 5 & 6 CKA/CKAD Live session we covered Introduction to Kubernetes, its Architecture, installation, Basic building blocks, Static Pod, and Kubernetes Basic Networking. And in this week, Day 7 and Day 8 we covered
We also covered hands-on Lab 14, Lab 15, Lab 16, Lab 17 Lab 22 & Lab 24 out of our 30+ extensive labs.
Know everything about the CKA Certification
Here are some of the Q/A’s asked during the Live session:
Kubernetes Deployment
A Kubernetes Deployment instructs Kubernetes on how to build or change instances of the pods that comprise a containerized application. Deployments can expand the number of replica pods, enabling controlled distribution of new code, or roll back to an older deployment version if necessary.
Q) What are the types of service in Kubernetes?
Ans: A Kubernetes Service is a logical abstraction for a deployed group of pods in a cluster. Pods are ephemeral a service that enables a group pod, which provide specific functions to assign a name and a unique IP address.
- ClusterIP – Expose a service that can only be accessed within the cluster.
- NodePort – Exposes a service via a static port on each node’s IP.
- LoadBalancer – Exposes the service via the cloud provider’s load balancer.
- ExternalName – Maps service to a predefined externalName field by returning a value for the CNAME record
↦ Read more about the Kubernetes Services
Q) What is the difference between deployment and service?
Ans: A deployment is a method of launching a pod with containerized application and ensuring the desired number of replicas is always running in the cluster. A service is responsible for exposing an interface to the pod. which is used to access networks within-cluster or between external services and processes.
Q) What is Istio?
Ans: Istio is a service mesh. It was developed by Google in collaboration with IBM and Lyft. It is a modernized service networking layer that provides a transparent and language-independent way to automate application network functions. It is used to manage different microservices that make up the cloud-native application
Q) What is the use of the controller manager?
Ans: Kubernetes controller manager takes care of the running cluster. It consists of several controllers functions and manages as one. The controller checks with the scheduler and makes sure the correct number of pods are running. If any pods go down controllers respond. It can also be used to connect services to pods.
Q)What are selectors and labels
Ans:
Labels are key-value that are attached to pods, replication controllers and services. Labels are used to identify attributes objects like pods and replication controllers. It can be added at object creation time and can be modified at run time.
Selectors are core grouping primitive in Kubernetes.it is used to select a set of objects labels.
↦ Read more about the Kubernetes labels and selectors
Q) What is the use of ReplicaSet?
Ans: A replica set ensures the guaranteed number of pods replicas are running at a time. A replica set is defined using fields with selectors it specifies how to identify pods it can acquire and the number of replicas indicating how many pods it should be maintaining and it also has a template. When a replica set needs to create new pods it uses its pod template.
Introduction to HPA and Kubernetes Networking
Q) What is HPA
Ans: HPA or Horizontal Pod Autoscalar is a mechanism available in Kubernetes to scale the number of pods in a replication controller, deployment, replica set, stateful set or a set of them, based on observed usage of CPU, Memory, or using custom-metrics.It works as a control loop when ever required metric is less or more than the threshold we declared. it will automatically scale up or scale down resources automatically.
Configuring Auto-scaling with HPA
Based on observed CPU use, the Horizontal Pod Auto-scaler automatically scales the number of Pods in a replication controller, deployment, replica set, or stateful set.
Q) What is Horizontal v/s Vertical AutoScaler?
Ans: Horizontal scaling means increasing its Running instance.It can be like adding new nodes to a cluster or increasing the number of pods by the replica count. Vertical Scaling means increasing the resources of nodes in a cluster. It will increase the capacity of the existing nodes by adding more resources(like CPU or Memory).
↦ Read more about the high availability in Kubernetes
Q) Do we have Vertical scaling also available with Kubernetes?
Ans: Yes
Q) What Kubernetes metric Server?
Ans: Metric server is used to measure resource usage across clusters. Kubernetes metric server collects resource metrics from the kubelet running on each node and exposes them to the Kubernetes API server through the Kubernetes Metrics API.
Deploy and Update Daemonset Controller
Kubernetes Dashboard
Cluster Resource Limit (Resource Quota)
Quiz Time (Sample Exam Questions)!
With CKA training program, we are going to cover 100+ sample exam questions to help you prepare for CKA certification. Check out the questions and see if you can solve this.
Here is the answer to the question shared last week
Ques) To create a new deployment in kubernetes which command you will use from the following options?
A. Kubectl run
B. Kubernetes get deployment
C. Kubernetes set deployment
D. None of the above
Write down the right answer in the comment box. The right answer will be revealed in my next week’s blog.
Related/References
- Visit our YouTube channel “K21Academy”
- Certified Kubernetes Administrator (CKA) Certification Exam
- (CKA) Certification: Step By Step Activity Guides/Hands-On Lab Exercise & Learning Path
- Certified Kubernetes Application Developer (CKAD) Certification Exam
- (CKAD) Certification: Step By Step Activity Guides/Hands-On Lab Exercise & Learning Path
- [Recap] Day 4: Dockerfile, Multistage Dockerfile, Docker Compose & Docker Image Scanning [CKA/D]
- Create AKS Cluster: A Complete Step-by-Step Guide
- Container (Docker) vs Virtual Machines (VM): What Is The Difference?
- How To Setup A Three Node Kubernetes Cluster For CKA: Step By Step
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