Kubernetes interview questions 2

Q21) Describe a few words about Kuberntes Controller Manager?

Answer: Kube-controller-manager is a divinity that embeds the crucial core control loops shipped with the Kubernetes. In most of the robotic and automation applications, control loops are the non-terminating loops that regulate the state of the particular system. In Kubernetes, the controller itself is the control loop that watches the shared state of the cluster using the apiserver. Examples of the controllers that ships today with Kubernetes are namespaces, replications, and many more.

The representation for the Kube-controller-manager is given as:

kube-controller-manager [flags]

 

Q22) What do you mean by the term etcd?

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Answer: Kubernetes uses etcd to store all its data. The reason behind it is that Kubernetes is a distributed system so as to store distributed data it uses etcd. Etcd s a distributed, most reliable key-value for storing the most critical data.

Q23) Define the term Minikube in Kubernetes?

Answer: To easily learn Kubernetes locally minikube tools is used. This runs on the single-node Kubernetes cluster inside a virtual machine.

Q 2 4 ) W h a t i s K u b e r n e t e s l o a d b a l a n c i n g ?

Answer: The process of load balancing lets you show or display the services. There are two types of load balancing in kubernetes, and they are:

Internal load balancing

External load balancing

Internal load balancing:

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This balancing is used to balance the loads automatically and allocates the pods within the necessary configuration.

External load balancing:

It transfers or drags the entire traffic from the external loads to backend pods.

Q25) List out the components that interact with the node interface of Kubernetes?

Answer: The following are the components that interact with the node interface of Kubernetes,

and they are:

Node Controller

Kubelet

Kubectl

Q26) Name the process which runs on Kubernetes Master Node?

Answer: The process that runs on Kubernetes Master Node is called the Kube-apiserver process.

Q27) What are Kubernetes Minions?

Answer: Node in the Kubernetes is called as minions previously, it is a work machine in the Kubernetes. Each and every node in the Kuberntes contains the services to run the pods.

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Q28) What is heapster?

Answer: Heapster is a metrics collection and performance management system for the Kubernetes versions. It allows us for a collection of workloads, pods, and many more.

Q29) Explain Kubernetes architecture with a neat diagram?

Answer:

Q30) What is the future scope for Kubernetes?

Answer: Kubernetes will become one of the most used operating system (OS) for the cloud in the future. The future of Kubernetes mostly lies in virtual machines (VM) than n containers.

Q31) What do you mean by Kubernetes?

Kubernetes is a technology developed by Google Research and Development Team, is available open source. Kubernetes allows Docker containers to establish multiple services at a time. Simply, it is a container management tool designed to work in different types of platforms. This tool is widely used to automate, scale, monitor, manage and deploy container based applications.

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Q32) State the important features of Kubernetes.

The features of Kubernetes are stated as follows:

It provides better infrastructure for Container based applications

It provides uninterrupted development services, deployment services and integration services.

It schedules operations automatically.

It restores a database or program to a previous defined state automatically.

It grades operations according to a scale automatically.

It corrects errors automatically.

Q33) What are the differences between Docker Swarm and Kubernetes?

Docker Swarm Kubernetes
Installing and Configuring the Installing and Configuring the
clusters is very easy but the clusters is very difficult but the
clusters were not resilient clusters were resilient (strong)
Docker Swarm does not Kubernetes dashboard is
contain GUI present in a GUI
Scales good with five times Scales faster but slower than
more faster than Kubernetes Docker swarm
Docker swarm does not scale Kubernetes scales automatically
automatically
Possess automatic load Does not contain automatic load
balancing feature through balancing feature and therefore
which it balances in case of require manual help in case of
any traffic between docker any traffic between containers
containers in cluster and the pods.
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Q34) What are the components of Kubernetes Master machine? Explain

The following are the key components of Kubernetes Master machine:

ETCD: ETCD is used to store the configuration data of every node present in the cluster. It can store good amount of key values which can be shared with several nodes in the cluster. Because of its sensitivity, Kubernetes API Server can only access ETCD. But, it contain a shared key value store which can be accessed by everyone.

API Server: Kubernetes itself is an API server controls and manages the operations in cluster through API Server. This server provides an interface to access various system libraries and tools to communicate with it.

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Process Planner(Scheduler): Scheduling is the major component of Kubernetes Master machine. Scheduler shares the workload. Scheduler is responsible to monitor the amount of workload distributed and used in the cluster nodes. It also keeps the workload after monitoring on the available resources to receive the workload.

Control Manager: This component is responsible to administer the current position of cluster. It is equivalent to a daemon process continuously runs in a unending loop which collects and sends the collected data to the API server. It handles and controls various controllers.

Q35) Explain the node components of Kubernetes.

The following are the major components of a server node to exchange information with Kubernetes.

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Docker: Every node contain Docker to run the containers smoothly and effectively. Docker is the basic component of every node in a cluster.

Proxy service of Kubernetes: Proxy service is responsible to establish communication to the host. Every node communicates with the host through proxy. Proxy service helps nodes to transmit data to the containers upon its request and is also responsible for load balancing. It is also responsible to control pods present in node, data volumes, creation of new containers, secrets etc.,

Service of Kubelet: Kubelet service helps every node to share information from the control pane and vice versa. Kubelet is responsible to read the details of node configuration and the write values which were present in the ETCD store. This service administers the port forwarding, protocols of network etc.,

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Q36) What do you mean by Kubernetes Name space?

Namespaces are given to provide an identity to the user to differentiate them from the other users. Namespace assigned to a user must be unique. Through namespaces, cluster resources can be separated and shared within the assigned namespace itself.

Q37) State the functions of Kubernetes name space.

The primary functions of Kubernetes namespace are stated below:

Namespaces assist information exchange between pod to pod through the same namespace.

They are considered as virtual clusters which will be present on the same cluster.

Namespaces are used to deliver logical segregation of team and their corresponding environments.

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Q38) How do you create a Namespace?

To create a name space, the following command should be written:

k u b e t c r e a t e f n a m e s p a c e . y m l

Q39) Write commands to control the Namespace.

To control the name space, we have to create a name space initially:

k u b e t c r e a t e f n a m e s p a c e . y m l

Then, we have to check the available namespaces from the list:

kubet get namespace

To get a specific name space we require, use the following command:

kubet get namespace<xyz>

To describe the services offered by the namespace, use the command:

kubet describe namespace<xyz>

If you want to delete a namespace from the list, use the following command:

kubet deletenamespace<xyz>

Note: xyz is given for example. You can give any name in the namespace region.

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Q40) Explain how will you setup Kubernetes.

Virtual Data Center is the basic setup before installing Kubernetes. Virtual Data center is actually believed to be set of machines which can interact with each of them through a network. If the user does not have any existing infrastructure for cloud, he can go for setting up Virtual Data Center in the PROFITBRICKS. Once completing this setup, the user has to setup and configure the master and node. For an instance, we can consider the setup in Linux Ubuntu. Same setup can be followed in other Linux machines.

Installation of Docker is the basic setup to run Kubernetes. But, there are some prerequisites needed before installing Kubernetes. We shall install Docker initially to start with. Following steps should be followed to install Docker.

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User has to provide login credentials and login as a root user

Install the apt package and update it if necessary. If update is needed, use the commands:

sudo apt-get update

sudo apt-get install apt-transport-https ca-certificates.