Kubernetes is an open-source system developed by Google for coordinating, running, and managing containerized applications in a cluster of machines. This system is designed to provide better methods of managing distributed and related components, as well as services across different infrastructure.
Besides, Kubernetes is designed to manage the lifespan of containerized services and applications using approaches that provide scalability, predictability, and high availability. When you become a Kubernetes user, you have the chance to outline how your applications must run, as well as how they should interact with the outside world or other applications. Besides, you can scale your services downwards or upwards, change traffic between various versions of your apps to test rollback problematic deployments or features, and perform rolling updates.
Kubernetes allows users to access composable platform primitives and interfaces, which allow users to define and manage their applications with high levels of power, reliability, and flexibility.
With that, let’s look at some of the common terms used for Kubernetes:
- Control plane – this is the pool of the processes that control Kubernetes nodes, and it’s also the origin of all task assignments.
- Nodes – this the host where a container runs on. Also known as the worker machine, it can either be a physical or virtual machine.
- Pod – this is a management unit within Kubernetes, and it can host different containers, together with a YAML file that identifies different attributes of the pod.
- Cluster – a collection of nodes managed by the master nodes.
- Replication controller – this controls the total number of identical pod copies that should run on a particular cluster.
- Service – this separates work rationale from the pods. Thus, the Kubernetes services proxies automatically transfer the service requests to the correct pods—regards to where it moves in the cluster, or if it requires replacement.
- Kubelet – this is a service that operates on nodes, reads the manifests on the container, and checks to make sure that the defined containers are up and running.
- Kubectl – this is a command-line alignment tool for Kubernetes.
Why Kubernetes?
The primary reason for using the Kubernetes container platform is to improve the efficiency of applications. The simple way to scale an application is to load one per container, generating new pods as required to support the increased traffic. Although this might be effective when a user has a few pods, it can be extremely ineffective and difficult to manage at a larger scale.
Every pod would need monotonous amounts of configurations, as well as wasteful resources. However, Kubernetes scales by assigning containers into pods automatically, depending on a smart technique known as load balancing, as well as requirement specifications.
The general structure of a cluster comprises one master node, which manages and coordinates the other clusters by connecting them to the other nodes. A Kubernetes cluster has three key properties, which are:
- Deployment – Kubernetes come with built-in tools, which make it easier to specify size allocation and resource parameters for an application.
- Development – here, load balances use services to automatically make changes to configure the pods.
- Monitoring tools – Kubernetes has many tools that show introspection into an application, in addition to the countless open source tools that display application data.
How to roll out a Kubernetes cluster
At the moment, there are numerous services available globally, that allow various Kubernetes implementations. Some of these popular services include:
- Minikube – this is an open-source utility, which users can install in their local machines if they want to use Kubernetes locally. Minikube uses a virtualization platform when setting up a local Kubernetes cluster.
- Google Kubernetes Engine – this is a solution developed by Google to manage production-ready Kubernetes for the user.
- Azure Kubernetes Services – this is a solution developed by Azure for the management of production-ready Kubernetes clusters.
- Amazon Elastic Kubernetes Services – this is a solution by Amazon which manages production-ready Kubernetes for the user.
- OpenShift Kubernetes – this is a solution developed by Red Hat to handle Kubernetes clusters for the user.
Please note that Minikube is the only open-source solution—meaning you don’t have to pay anything to use it. However, it comes with one major downside—it only runs locally. While some of these solutions provide free services that allow users to get started without paying anything, the user will need to pay eventually to keep the clusters running.
Getting Kubernetes
The design of Kubernetes allows the system to be installed either on cloud providers or on-site hardware. Today, most cloud service providers, together with third parties are now providing managed Kubernetes services. But, you should note that this can be costly, and unnecessary for testing or learning experience. So, the best and quickest method for users to get started with Kubernetes in a test environment or isolated development is through Minikube.
Installing Kubernetes
Installing Kubernetes is not a difficult task—users will need two things to get started—Minikube and Kubectl.
- Minikube – this is a binary that allows the deployment of a cluster locally on a development machine.
- Kubectl – this tool allows the interaction of clusters.
Now, with these two tools, users can start deploying their containerized applications to a local cluster in just a few minutes.
