Key Takeaways
- Containerization involves packaging an application’s source code with the libraries and utilities needed to run it properly.
- The majority of businesses utilize containerization for app development and deployment.
- Kubernetes is the most popular container orchestration and automation solution.
- Kubernetes is a container orchestration system developed by Google based on their Borg system.
- Kubernetes groups servers into clusters, labeling each machine as a node.
- Each node hosts pods that contain multiple containers. Each container contains various parts of the application that together power the app.
- Kubernetes provides unique benefits, such as a zero-downtime application deployment environment and advanced horizontal scaling.
- Security and portability are also emphasized by Kubernetes, providing a highly secure and versatile app development and deployment environment.
- The future looks bright for Kubernetes, with more and more businesses leveraging containerization as time progresses.
Containerization has been a hallmark of application development for quite some time now. It allows applications to be isolated from other software and prevent conflict. Container management is an incredibly important task. As an application grows, it becomes more complicated to manage. Kubernetes is among the most popular container management and orchestration solutions available.
Today, we will answer the question: what is Kubernetes? With many new faces joining the programming community, this should prove a handy resource for getting started with app development. We will cover the core concepts and design decisions governing Kubernetes and some of its standout features. Let’s jump right into it.
Table of Contents
- Key Takeaways
- What is Kubernetes?
- History of Kubernetes
- How Kubernetes Works
- Key Features of Kubernetes
- Benefits of Kubernetes
- Conclusion
- FAQs
What is Kubernetes?
Image Credit: Kubernetes
Kubernetes, also known as K8s, is an open source container orchestration and management software. It specializes in consolidating and automating scattered, complex applications into one unified whole. The name comes from the Greek word for helmsman; an appropriate title for a software leading the cloud-native revolution.
In an interview by the Enterprisers Project, Gordon Haff of Red Hat put forward the following explanation for Kubernetes:
“Container orchestration builds on Linux to provide an additional level of coordination that combines individual containers into a cohesive whole.”
When applications grow more complex, it becomes easier for developers to split the many parts of the app into individual containers. For example, an application’s frontend, backend, and database can be split into individual containers, which work together to deliver a complete experience. By splitting into containers, they become easier to individually manage and scale with the help of tools like Kubernetes.
History of Kubernetes
Google originally developed Kubernetes as an open-source container orchestration tool based on its internal containerized workload management system, Borg. It was a massive hit, with tech giants like Microsoft and IBM signing up to be part of the original Kubernetes community. A year after its release, in 2015, Google handed over ownership of Kubernetes to the Cloud Native Computing Foundation.
In 2016, Kubernetes became the CNCF’s first hosted project, and its popularity has risen ever since. Today, Kubernetes is the most used container orchestration tool used by enterprises. As reported by the CNCF, Kubernetes is the container orchestration tool of choice for around 71% of Fortune 100 companies.
How Kubernetes Works
To understand Kubernetes, we need first to understand the core concepts on which it is built. By breaking it down to the core components and terminology, we can better grasp exactly how Kubernetes harnesses the power of container orchestration.
Kubernetes Cluster
A Kubernetes cluster can be defined as a group of host computers or servers running Linux containers. Typically, Kubernetes is used with a network of physical or virtual machines in an enterprise setting. While a single machine can be used as a Kubernetes cluster, it misses out on some of the core advantages of the tool.
Kubernetes Nodes
Every machine in a Kubernetes cluster is referred to as a Node. Put simply, if five servers are used with Kubernetes, they are called nodes and collectively called a cluster. Not all Nodes are created equal. A Kubernetes cluster can be divided into two main nodes: the Master Node and Worker Nodes.
The Master Node
One of the nodes is typically assigned the role of Master Node. This node, also called the Kubernetes control plane, administers the cluster. It comes with management utilities for the job, which include:
- API Server: The API server is your entry into the control plane and is responsible for managing RESTful calls
- ETCD: A distributed key-value store that holds and manages system-critical data.
- Scheduler: The scheduler examines workloads and assigns pods to nodes depending on how many resources are needed to complete the task.
- Controller Manager: Controllers are used in master nodes to manage the cluster state. The controller manager allows control over different types of controllers, such as node, endpoint, and replication controllers.
The Worker Nodes
Worker nodes are the machines that actually execute the computing processes required for the application. The master node orchestrates everything, telling the worker nodes what they must do. Worker nodes are equipped with essential services for deploying and managing containerized applications. These services include:
- Kubelet: The Kubelet facilitates communication between master and worker nodes and provides status reports on the node and associated pods.
- Container Runtime: Container runtime software runs containers in a node. It pulls container images from a registry, starts, stops, and manages the lifecycle of containers, ensuring they are running according to the defined specifications.
- Kube-proxy: Each worker node uses Kube-proxy as a network proxy. This proxy maintains network communication with pods from inside or outside the cluster.
Kubernetes Pods
A Pod is the smallest object in a Kubernetes Cluster. Just like multiple nodes form a cluster, multiple pods form a node. A pod is the smallest instance of a running process in the Kubernetes cluster and comprises one or more containers. Each pod contains tightly connected containers that share resources like storage.
Kubernetes Services
Pods are constantly changing in Kubernetes. When a pod is no longer required, it is destroyed. If a node requires more pods, they are generated and distributed to the node. Services maintain a consistent identity for a set of pods in a node. Even as pods are destroyed and replaced, the service ensures a single identity remains for external users or parts of the application to interact with.
By identity, we mean network identity, such as a unique IP address and DNS name. Keeping the same IP and DNS even as pods under them change allows uninterrupted access to the pods and their resources and processes.
Kubernetes Deployment
Deployment is an advanced concept in Kubernetes. To understand deployment, we must understand how Kubernetes handles downtime and state-maintenance. Kubernetes allows administrators to create and maintain multiple replicas of a pod automatically. These replicas run simultaneously and are used to divide load if there is a surge or pick up the slack if a pod or node fails.
Deployment is the tool admins use to facilitate a zero-downtime environment. Replicas are a part of this endeavor, as are zero-downtime software updates and rollbacks. Deployment allows admins to specify how many replicas of pods should be running at one time. It also allows them to update pod software individually to maintain the application without downtime.
Deployment is also used for state maintenance. Using Deployment, admins can set a declarative state for the application. Kubernetes will then do everything in its power to deliver the desired state.
Namespace
A namespace is an isolated virtual environment with a pre-defined resource allocation. Think of it this way: it is like creating multiple users on the same computer. When one user is logged in, they utilize the resources without affecting other users. Now imagine a computer where two users are simultaneously logged in and can use the same pool of resources without interfering with each other’s work.
A namespace is the Kubernetes version of a user in this example. All namespaces share the same pool of nodes for running workloads. Nodes are responsible for running pods from any namespace based on the scheduling decisions made by Kubernetes, ensuring efficient use of resources across the entire cluster.
Key Features of Kubernetes
As a container orchestration solution, Kubernetes is in a league of its own. Here is a quick glimpse at some of the hallmark features of Kubernetes that elevate it above the rest:
Benefits of Kubernetes
Kubernetes did not become so influential simply because Google backed it. It is a genuine marvel of modern technology and brings many unique benefits to the table. Let’s discuss some of the ways Kubernetes changed the containerized application landscape and why it is so beloved today:
Automated Scalability
Kubernetes’ biggest achievement is bringing seamless automated scalability to application development. There are several different scalability tools present in the Kubernetes ecosystem:
The Horizontal Pod Autoscaler (HPA)
The HPA is an automated scalability solution for efficient cluster management and load balancing. It automatically manages the number of replica pods active in a node and initiates replica use if one pod proves insufficient. Admins can set rules for the HPA to follow. For example, it can be configured if a pod crosses a defined CPU usage threshold.
Once this threshold is reached, Kubernetes will shift the excess load to a replica pod autonomously. Both pods will thus share CPU usage and keep the overall strain on a single pod low. This reduces pod failure rate and creates a dynamic response system for shifting workloads.
Cluster Autoscaler
If the current number of nodes in the cluster is insufficient for hosting required pods, Kubernetes can automatically commission new VMs for nodes. This is typically done through a combination of automation and cloud services. Cloud server providers like Google Clow, Microsoft Azure, and AWS provide access to their APIs for node scaling.
Admins can configure Kubernetes to request additional VMs if the cluster lacks resources. This is all done via the cluster autoscaler. If the enterprise does not use cloud infrastructure and instead uses bare metal servers, it must manually provision additional nodes.
Also Read: Google Cloud vs AWS vs Azure: The Ultimate Cloud Service Battle
Zero-Downtime and High Availability
Image Credit: Freepik
The Kubernetes platform prides itself on providing a consistent, uninterrupted application execution environment. The software emphasizes high availability on an infrastructure and application level. Features like replica pods and horizontal scaling allow for high availability. If one node or pod goes offline, Kubernetes adapts and can commission new nodes and pods to take its place.
In terms of infrastructural availability, Kubernetes supports many notable distributed storage backends. AzureDIsk, NFS, and Google Persistent Disk are some of the major supported backends. A secure and accessible layer of storage ensures high availability for stateful pods. Stateful pods are pods that house application-critical data that cannot be deleted and is uniquely identifiable.
Even the master node and other administrative components can be replicated to ensure availability even if the master node fails.
Security
Image Credit: Freepik
Regarding security, Kubernetes has multiple provisions to control access and hide sensitive information. Features like Role-Based Access Control (RBAC) ensure that only relevant pods and nodes are visible to concerned parties. Developers, for example, only have access to the application’s development nodes and nothing more.
Kubernetes also has features like network policies, which can restrict and control communications between pods. This prevents any exploitation of the node network to gain unauthorized access to confidential information. Kubernetes Secrets provide a secure way of encrypting and storing sensitive information separate from the visible code in containers.
Portability
Image Credit: Freepik
Kubernetes is highly portable and versatile, working with most mainstream Linux distributions. It supports mainstream processor architectures and is also compatible with all manners of servers. Nodes can be bare metal servers or virtual machines hosted by cloud services. Kubernetes is also highly complementary to Docker, an extremely popular container runtime.
You can run Kubernetes and maintain workloads across hybrid, i.e., private and public cloud environments and multi-cloud environments through Federation. This concept also supports availability-zone-fault-tolerance in a single cloud provider.
Conclusion
Kubernetes is a miraculous technology that revolutionized scaling containerized application management. The robust technology behind Google’s rock-solid infrastructure finally became available to the public with Kubernetes. By 2027, Gartner predicts that 90% of global organizations will use containerized applications. The future shows a lot of promise for Kubernetes.
If you have not yet leveraged the power of containerization for your applications, it may be time to hop on the train. As development becomes more complex and sophisticated, containerization will only become more necessary. To that end, setting up robust dedicated server hosting is the first step to harnessing the power of Kubernetes.
RedSwitches offers just the right solution for small and large businesses alike. Whether bare metal server provisioning or dedicated server hosting, few options compete with what RedSwitches can provide. Join the RedSwitches family today and start your first Kubernetes Cluster on our affordable yet robust hosting solutions.
FAQs
Q. What is Kubernetes used for?
Kubernetes is an open source containerized application management platform. It began as a publicly available derivative of Google’s Borg management system. Currently, Kubernetes is the most popular container orchestration solution for scaling applications.
Q. What are Kubernetes clusters?
When referring to “ Kubernetes Clusters,” we are talking about a network of physical or virtual machines being used to run containerized applications. Kubernetes labels every machine in this network as a node, and the nodes contain pods that house a number of containers running application processes.
Q. Can Kubernetes improve my app’s reliability?
Kubernetes is an excellent solution for applications requiring high availability. The deployment and service features make Kubernetes highly reliable. You can replicate and provision new nodes and pods to dynamically meet application requirements and cover for system failures.
Q. Is Kubernetes good for web app deployment?
Kubernetes is an ideal solution for deploying web apps. It ensures smooth deployment with an intuitive interface that simplifies the complex back-end processes.
Q. Can Kubernetes work with my current cloud provider?
Kubernetes can seamlessly integrate with multiple cloud providers like Microsoft Azure and AWS. Admins can even grant Kubernetes permissions to provision VMs for nodes as required automatically.
Q. Do I need to learn Docker to use Kubernetes?
Docker is the most widely used container runtime. You will often see Docker deployed alongside Kubernetes for a seamless containerization solution. Docker and Kubernetes are often considered rivals but are much better represented as complementary solutions.
Q. Will Kubernetes help reduce costs?
While Kubernetes does not directly induce cost savings in a business, its presence can bolster cost savings in other ways. For example, the efficiency and productivity boost from using Kubernetes in development can help save a lot of time and money.
Q. What is the Kubernetes feature for application monitoring?
You can use monitoring tools like Prometheus and Grafana, which are compatible with Kubernetes. These tools can monitor and track application and system health and provide real-time data.
Q. How hard is it to learn Kubernetes for beginners?
Because it is so feature-rich and constantly evolving, Kubernetes can seem overwhelming to beginners. The learning curve is quite steep, but fortunately, there is extensive documentation and a very active community of contributors to help beginners learn the ropes.
Q. What is the benefit of using Kubernetes for my DevOps team?
Kubernetes streamlines development workflows, automates repetitive tasks, and ensures consistency across development, testing, and production environments.
