Are you also dealing with containerized services and workloads? I gotcha!
According to recent data from Dynatrace, the share of cloud-hosted clusters has increased from 31% in the year 2021 to 45% in the year 2022.
In this article, I am going to talk about Kubernetes Tutorial For Beginners, and all the other factors regarding Kubernetes for Beginners.
What is Kubernetes?
Before you start with the Kubernetes basics for beginners, you must know enough about Kubernetes.
Kubernetes is one of the most in-demand container orchestrating tools for scaling and deploying containerized systems.
I believe that this is one of the most reliable platforms that I can use to build and distribute my applications in cloud storage.
An interesting thing to know about Kubernetes is that they are also known as K8s. This is a word derived from a Greek word, which means “a pilot.”
In 2014, Google designed Kubernetes as an open-source platform through which you can automatically deploy, scale, and manage container-based applications across the nodes’ clusters.
There are times when you need to manage the services provided by containerized apps for great availability, scaling, managing productivity, etc. Google designed Kubernetes to take care of all such activities.
I am going to provide you with a perfect Kubernetes advanced tutorial and guide so that you can enhance your overall knowledge about that.
What Are The Components of Kubernetes Node?
There are several components of the Kubernetes Nodes server, which you need to take into consideration as Kubernetes beginners.
In the following list, I will be talking about the components of Kubernetes Node.
First things first, the primary requirement of Node refers to Docker. It helps to run the encapsulated application containers.
Docker also helps in running a lightweight operating environment.
2. Kubelet Service
Each node's service is responsible for reading configuration data from the etc store and updating values to send data across the control and data planes.
Kubelet services are required to manage network rules, the work state, the node, and port forwarding.
You must know that Kublelet services are a prominent component of Kubernetes Node.
3. Kubernetes Proxy Service
Kubernetes Proxy Service is a node-based proxy service that facilitates the delivery of services to an external host, which is a prominent feature of Kubernetes for beginners.
I have found that one of the most important features of this component is to manage pods on nodes, secret, new container creation, volumes, and more.
This helps the requests get routed to the right containers, and focuses on some load balancing.
This service ensures that the networking environment must be reachable, most certainly isolated, and predictable.
4. Setting Kubernetes
A virtual Data Center (VDC) refers to a group of machines responsible for communication purposes within a network.
Let me tell you that before you begin with Kubernetes as a beginner, you would need to set up the Virtual Data Centre.
The primary step is to complete setting up the IaaS on the cloud. Then you would need to finish the configuration of Master and Node.
Kubernetes Tutorial: Basic Terms and Concepts
There were as many terms and concepts that I came across in the Kubernetes guide. And it was hard for me to know and deal with all the terms all at once.
So, I am going to talk about the same to get you off your confusion and unawareness.
What are Nodes? There is something very technical about it, but I was able to understand it quickly.
Your Kubernetes cluster's physical machines are referred to as nodes, which control the containers that you have built.
Kubernetes reflects your nodes as an object and tracks their states. It also claims that it can host up to 5,000 nodes, but my new cluster only contained one node.
There is a possible expectation for Kubernetes to expand the nodes even further.
Namespaces help minimize the collision of names by reducing the amount of resource visibility, and it also isolates and divides the various types of resources.
You would not be able to make two objects having similar names in one namespace. This ensures uniqueness, authenticity, and also differentiation.
I have been using Namespaces as a very flexible tool in many different contexts. If you want to keep your cluster’s task unique, then you must give each of your cluster’s tasks its namespace.
One more exciting thing about Namespace is that the “Role-based access control” can be effectively utilized for the division of resources across teams and users.
In this Kubernetes basic tutorial, the fundamental computing units of Kubernetes are Pods.
You must think that a container and a pod are almost the same things, but there are several key differences that you should be aware of.
One of the main features of Pods is that they can contain many containers, and each container shares its context. One of the main features of this is that all the Pods will end up on a similar Node.
The database and API is a great examples of why you should build a separate Pod for every unique part of the app you are creating. The reason behind this is that the Pod container is highly interdependent.
There can be two cases of which you should be aware. Firstly, you would see a simple situation where the Pods and the containers in which your application runs will map one-to-one.
Secondly, it is a complicated case, where Pods usually get supported with the ephemeral containers and init containers so that you would be able to support your startup behavior and get complete & thorough debugging.
When it comes to offering rollbacks and declarative updates to ReplicaSets, then Deployment comes into action and takes over this issue.
Deployment has a greater level of abstraction and a very simpler way to control. You can specify the required sets of Pods using the Deployment object, which will include all the clones that run.
Let me tell you how Deployment is helpful for replicas. The moment you modify the Deployment, Deployments will instantly recognize the required adjustments and scale the ReplicaSet appropriately.
There are times when you would need to replicate a Pod. You will need to use ReplicaSets for this purpose. In this way, you can ensure that a specific number of clones will always be active and running.
ReplicaSets help in emergencies for instance, if a node fails or a Pod gets defective, then Kubernetes will launch a new Pod right away.
The network can access pods using the Services, through which they grant certain Pods access to the inside or outside of your cluster access. There is a new term that you need to know. Ingresses refer to objects that are closely related.
You can utilize them to get HTTP services provided by the load balancer. I was also able to use the Ingresses for TLS certificates to support and secure the HTTPS traffic.
You can use Volumes to mount an external filesystem within your Pods using volumes through which they can obscure the differences in storage options across several other cloud service providers.
You may share Volumes amongst your Pods. Volume can help Kubernetes to execute stateful apps when a Pod is terminated or rescheduled ensuring that all the data has been preserved.
There is an important thing to note you must use a volume when running a file server or a database in your cluster.
You must have heard of an object known as a Kubernetes Job. It creates a group of Pods and then waits for them to finally terminate at the end. Up until a specific amount of the Pods have successfully left, it will attempt any unsuccessful ones again and again.
An extraordinary feature of Jobs is that it allows you to run Ad-hoc tasks that may be carried out inside your cluster. CronJobs is a part of Kubernetes, which wraps Jobs with cron-like scheduling support.
You can run a Job automatically to handle backups, batch operations, or several scheduled procedures for your application.
9. Secrets and Configuration Maps
When I was a beginner in Kubernetes, I have always been concerned about the sensitive data that I need to put into my cluster. Well, with Secrets, there is no such concern left because it helps inject sensitive data into the cluster.
The data could be anything like certificates, API keys, or any other form of confidential credential.
The method that they are in needs to be sent to pods as mounted in Volumes or as environment variables.
On the other hand, ConfigMaps just act the same as Secrets, but they are not for sensitive data. You can keep all the necessary settings that your app requires.
You can also run a Pod replica on each Node in your cluster using DaemonSets.
The best thing about DaemonSets is its immediate actions, for example, the moment another Node comes in, DaemonSets will automatically run an instance for the same.
The above condition is a basic situation for Kubernetes beginners, but you can level up to an Advanced situation. You have the option to restrict DaemonSet Pods to only run on certain Nodes.
You can easily use DaemonSets for giving global functionality to your cluster by typically running log aggregation agents and monitoring services. DaemonSet ensures that they are always running alongside the Pods of your application.
11. Networking Policies
A policy-based architecture is available to you by Kubernetes for taking care of all the network traffic that enters and leaves between Pods.
You may isolate the delicate Pods from different resources to stop attackers from passing using the infrastructure. In this way, you can ensure security which must be your priority.
Objects that target one or more Pods are used to express network policies. There may be rules governing entry and exit for each Pod.
Egress policies deal with the effect of outbound flows and control departing flows. On the other hand, the ingress policies control the incoming traffic allowed.
The network policies have to allow the ingress and egress on the Pod. This is the primary condition for communications between two Pods.
If you want to learn more about Kubernetes then you can take a professional course at discount using a Linux Foundation coupon.
What Are The Features Of Kubernetes?
Here are some of the main features of Kubernetes.
1. Automated rollouts, scaling, and rollbacks
Kubernetes helps in creating the required number of clones automatically. This is done in a given order which is.
Firstly, if a node fails, it distributes them to the right hardware and then goes ahead with taking action to reschedule containers.
I was able to quickly scale the number of clones that were needed. In the case of any change or fluctuation in the condition of CPU use, I could scale them as well with ease.
2. Service discovery, load balancing, and network ingress
I was able to get Kubernetes’s entire solution for networking. This comprises both public container exposure and internal service discovery.
3. Stateless and stateful applications
You must have heard that Kubernetes was initially concentrated on containers that are stateless. But it has leveled up to objects that are built-in to represent applications that are stateful.
An amazing feature of Kubernetes is that I was able to run any type of application in it.
4. Declarative state
If you want to create the cluster state, then Kubernetes is here to help you by manifesting in YAML files.
Kubernetes is given instructions that automatically help in the transition from the cluster to your desired state when a manifest is applied.
I never had to make the script manually for the changes that I wanted to see.
5. Storage management
Persistent storage is abstracted using a standardized interface for all the service providers. This could be in the cloud, a local disc, or on a network share.
6. Highly Extensible
One thing that I have noticed is that Kubernetes already has a tonne of functionality. But you would use extensions to let you add even more functionality to it.
You may create your object types, operators, and controllers to accommodate your workloads.
7. Work Across Environments
I have loved the versatility of Kubernetes about how it may be used on developer desktops, in the cloud, or on the edge. You will see various distributions available to accommodate several use cases.
Major cloud providers like Amazon and Google Cloud provide managed Kubernetes services. Or if you need something for local use then single-node versions like Minikube and K3s are most suitable.
Kubernetes Architecture for Beginners
You must know about the architecture of Kubernetes so that you can have a better picture in your head about what you are going to deal with. Below is the list of all the Kubernetes Architecture-
1. H3 Master Component
Systems that are at the infrastructure level, for example, CoreOS strive to provide a uniform environment where every host is interchangeable and disposable.
But also, the operation of Kubernetes has a certain degree of host specialization.
You can call the Kubernetes cluster controlling services by the name- master or control plane components.
They may be installed on a single server or dispersed among a number of them.
You would also notice that they operate on the central administration interface for administrators, providing a variety of cluster-wide systems for the relatively simple worker nodes.
Etcd has information about a configuration that the cluster nodes can use. I have noticed that It has a high availability key-value store distributed across several nodes. Only the Kubernetes API server can access the key-value store since it holds sensitive data.
3. API Server
API server manages all cluster operations by utilizing libraries and a variety of tools that are easy to communicate with. Kubeconfig comes with a server-side tool to expose the Kubernetes API. You would see how an API server is effective in communication.
4. Controller Managers
The main task of controller managers refers to managing the state of clusters.
It is also known as Controller, and can also be referred to as a daemon that deals with the non-terminating control loops. It is responsible for sending and receiving data from the API server.
You would not have to manually do any modification for it, rather the Controller can get the server to the desired state by collecting shared data and carrying out the modification.
The controller manager has some prominent key controllers that include the following-
- Replication controller
- Namespace controller
- Service account controller
- Endpoint controller
The many controller types that manage nodes, endpoints, and other entities are managed by the controller manager.
The scheduler is in charge of allocating pods to open nodes and manages the workload utilization. It is an essential part of the Kubernetes master for monitoring the work utilization load and is in charge of distributing workloads on cluster nodes.
This also helps in accepting the workloads from all the available resources.
Advantages & Disadvantages of Kubernetes
Here are some of the main advantages & disadvantages of Kubernetes:
|Kubernetes can help you in finding all the suitable tools and resources
|Security in Kubernetes doesn't work very well
|It was launched by Google, and we all know the contribution Google has made to technology
|It is not very needful and suitable where all work is done locally
|Public clouds, on-premises storage, and SANs. All these types of storage options are available on Kubernetes for beginners
|Kubernetes can improve its dashboard for beginners
|Kubernetes’ Pods provide simple and straightforward service organization
|One of the main benefits of the Kubernetes tutorial for beginners is that it will let you avoid vendor lock issues. It is because of the vendor-specific APIs
|Kubernetes tutorial for beginners is available
|Beginners in Kubernetes can get several package software for containerization. There will be no downtime for an application that you need to release or update
|It will ensure that the applications that you have containerized run wherever and whenever you want
|Kubernetes has an unbelievably active and huge community in container orchestration technologies
|There are several platforms that Kubernetes can work on. For example, OpenStack, on-premise bare metal, public clouds, Google Azure, and more
What is a Deployment in Kubernetes?
When we combine several identical pods, we get Kubernetes deployment.
This is one of the most important things that Kubernetes beginners should know about. So, read carefully ahead!
One of the reasons that you need deployment is that they are highly responsible for running several replicas of your application.
There would be many times when one of the instances of your application could crash, fail, or stop responding. This is when deployment comes into action ensuring that there must be one instance always that is active.
Kubernetes deployment controller deals with all such tasks of deploying.
Do you know how Kubernetes carry out its deployment? It is done by using Pod templates. These pod templates define the behavior and appearance of the pod, including the volumes it mounts, taints, labels, and other actions.
How to Install Kubernetes on Linux?
When I was about to Kubernetes on Linux, I thought it was going to be a hard task.
But it was not like that at all. It is certainly a very simple process that you need to follow step-by-step.
I am mentioning all the steps below which you can follow to install Kubernetes on Linux-
We will be using two commands and updating the necessary dependencies of the system.
Open the terminal box of the system and execute the following command-
sudo apt-get update
After successfully executing the first command, you would need to run the second command-
sudo apt-get install -y apt-transport-https
In this step, we are going to install the dependencies of docker.
Choose Y to confirm the installation process and then run the following command-
sudo apt install docker.io
After you get done with the docker installation, you need to start and enable the docker. For this, you need to run the following command.
To start the docker, run-
sudo systemctl start docker
To enable the docker-
sudo systemctl enable docker
To identify the docker version, run-
The third step is to install the curl command which is responsible for sending the data using URL syntax.
Type Y in the installation process.
For installation, run the command-
sudo apt-get install curl
For downloading the add package key, run the command-
sudo curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add
To add the Kubernetes repositories, run the command-
sudo apt-add-repository "deb http://apt.kubernetes.io/ kubernetes-xenial main"
To check for updates, run the command-
sudo apt-get update
In the fourth step, we need to install the components of Kubernetes by running the following command-
sudo apt-get install -y kubelet kubeadm kubectl kubernetes-cni
The next step is to initialize the kubeadm.
Run the following command to disable the swapping on any other devices-
sudo swapoff -a
Initialize the kubeadm by running the command-
sudo kubeadm init
We have to run the following command to start a cluster:
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
The following command will help in deployment-
sudo kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
The last step is to verify the installation. For that, you need to run the command-
sudo kubectl get pods --all-namespaces
In this way, you would be able to successfully install Kubernetes in Linux.
If you want to improve your Kubernetes skills then you can take a course on Linux Foundation using the Kubernetes certification coupon to avail yourself of some discount.
I hope that this article about the Kubernetes beginner tutorial has been helpful for all the Beginners out there and has provided a proper Kubernetes guide.
If you are willing to change your game and level up in containerizing services and workloads, then you must get started as one of the Kubernetes Beginners.