Originally designed by Google and now maintained by the Cloud Native Computing Foundation, Kubernetes (aka K8s) is an open-source container-orchestration system for automating software deployments.
Kubernetes is a very popular platform for managing containerized workloads and services. Kubernetes services, support, and tools are widely available. It works by organizing applications in groups of containers which are virtualized host operating systems or kernals. Containers isolate an application’s dependencies from other containers on the same machine. This approach improves resource utilization and lowers costs.
Frequently Asked Questions
What is Kubernetes? Kubernetes is a system that depends on virtualizing the operating systems rather than virtualizing the hardware.
What is Kubernetes used for? It is used to divide Linux applications into smaller, independent pieces called microservices which can be deployed and managed independently.
What are the benefits of Kubernetes? Kubernetes containers are easier to build than virtual machines. Because they are self-contained and independent, Kubernetes containers are portable and extendable. It can deploy apps to public, private or hybrid clouds without disruption and at less cost.
What are pods in Kubernetes? Pods are the smallest deployable units of computing pieces that can be created or managed in Kubernetes.
What is the difference between Docker and Kubernetes? The core difference is that Docker is meant to run on a single node while Kubernetes is meant to run across a cluster.
Kubernetes automates many operational tasks in software deployments and allows the user to schedule and run containers on clusters of physical or virtual machines in public cloud, private cloud and hybrid environments. Given its extensibility, portability, agility, and automation capabilities, Kubernetes is an ideal system for the management of containers that improves the utilization of resources and reduces costs. It is a stable and reliable system with a large and growing ecosystem that ensures continued support. It is useful and highly advantageous to any organization that doesn’t have a large microservice environment.
Kubernetes provides the following services:
- Compute scheduling: automated resource determination and assignment per container
- Self-healing: if a container malfunctions another is created in its place automatically
- Horizontal scaling: Kubernetes adds or removes instances according to outputs of CPU and other resource metrics
- Volume management: persistent storage is managed according to application use
- Service discovery/load balancing: Multiple instances, DNS and IP address are load-balanced
- Automated rollouts and rollbacks: If a new instance should fail, a rollback to a previous version happens automatically.
- Secret & configuration management: Applications secrets – typically things like passwords, API keys, digital certificates and other security factors – and application configurations are automatically managed.
Benefits of Kubernetes
Kubernetes is primarily used to improve DevOps productivity, manage changes to existing containerized applications, and to optimize hardware resources. Kubernetes can deploy apps on public clouds, private clouds, and in hybrid environments. Because of these and other capabilities, Kubernetes is a key element of software-defined infrastructures too.
The point in using Kubernetes is to fully leverage the benefits of containers, a form of operating system virtualization that can run anything from tiny microservices to entire applications. Containers are easier and cheaper to build than virtual machines.
Each container is self-containing and includes all necessary executables, binary code, libraries, and files, including configuration files. Each container is thus independent of other containers on the same machine, are highly portable, and extensible.
Kubernetes manages containers to gain further efficiencies and control.
Managed Kubernetes vs. Hosted Kubernetes
While Kubernetes simplifies software deployments in many ways, it isn’t simple to use. That’s why some users may elect to use a provider-managed Kubernetes service like Amazon Elastic Kubernetes Service (EKS) and Google Kubernetes Engine (GKE) to manage Kubernetes services and master nodes. However, ease of use comes with a trade off in control and options. Therefore, some users may prefer to self-manage Kubernetes in a hosted service. You can deploy a cluster through kubeadm, kubespray, or manually. In each of those cases, you have full access to the cluster, master nodes, and all the other related management components.