Containers are the next evolution of virtualization after virtual machines, and Kubernetes — an open source platform — is the most popular solution people use to build, scale, schedule, and monitor containerized applications.
The benefits of using containers and Kubernetes together are that you get a low-cost, high-performance environment for your cloud-native applications, faster development and deployment, and improved efficiency, flexibility, and scalability.
Most developers already know they can build and deploy containerized applications wherever they want and manage them however they want. Kubernetes adds even more efficiency and flexibility because it takes over many traditional tasks associated with making sure applications are up and running and stay healthy. Those requirements have not gone away.
The challenge of running Kubernetes in containerized applications is that you need a significant amount of knowledge and expertise to effectively use it. The first step is understanding the basics of how containers and Kubernetes work.
How Containerized Applications and Kubernetes Work
Containers do for the operating system what virtualization did for the computer. Essentially, you get your own virtual machine for each application and don’t have to worry about provisioning and managing a full operating system, as long as you are effectively managing the container images.
In containerization, applications are broken into small pieces, often as microservices, and packaged with all the elements needed to run applications consistently in any environment — on premises, public cloud, multi-cloud, etc. Inside the container are traditional hardware services (memory driver, disk, network interface, and CPU), the host operating system, the container runtime, bins/libraries, and the application.
Kubernetes runs on top of the operating system to ensure that each container is where it’s supposed to be and works together with other containers so that services run smoothly, and as designed. Kubernetes also makes sure long-running services keep running while maintaining a balance for intensive short-term work, such as builds.
When you run Kubernetes in a container, it creates a Kubernetes cluster that consists of one or more nodes (worker machines) that run the application. The node(s) host pods that contain the components of the applications workload. The control plane is the orchestration layer — a governing set of processes that acts as the communications director for a Kubernetes cluster.
Each node must include a container runtime, such as Docker, which accesses container images and runs the application; as well as a Kubelet, a communication process that lets the control plane manage the nodes. Nodes can consist of one or multiple pods.
Kubernetes manages clusters and schedules containers to run most efficiently based on the available computing resources and the requirements of each container. Managing these clusters, and the storage they require, is called orchestration.
The difference between deploying containerized applications with Kubernetes and without Kubernetes is that without it, you’ll still have a lot of manual work to do. There are digital tools that can help you manage containerized workloads, but Kubernetes takes it to the next level of defining services and deployments that dictate the way images are spun up and spun down. The Kubernetes infrastructure has its own virtualized networking layer that allows you to do virtualized load balancers that inform the Kubernetes engine what to do.
Adequately Plan for Ramping Up with Kubernetes
If you want your team to start using Kubernetes, plan for ample learning and preparation time because Kubernetes is really an infrastructure solution that needs to be set up and configured.
For example, a significant amount of effort will go into defining compute, networking, and storage. If you are using a public cloud, you can use their services to reduce some of this time and effort. AWS offers Elastic Kubernetes Service; Azure offers Azure Kubernetes Service; and Google offers GKS.
Once the infrastructure is set up, Kubernetes is very flexible, but that also means there’s a lot of configuration that has to be done to manage traffic, security, and services depending on what the applications are doing.
You’ll also have to plan for the typical requirements once the application is up and running:
- How do I monitor and maintain the cluster and my application?
- How do I determine the scaling?
- How do I ensure failover across regions?
- How am I going to handle patches to the operating system?
Kubernetes is a powerful technology, but it’s not a plug-and-play solution. It is most beneficial when it is set up properly and used to its full potential, and that can be a complex endeavor for some organizations.
Help with Getting Started with Kubernetes
Kubernetes has a following of active users who love to talk about it, and a lot of educational resources are available. While tapping into these resources can help with learning and adoption, there are also ways to reduce complexity while also shortening the learning curve.
We talk about this more in our Tech Talk, Managing Kubernetes Implementations at Scale. Watch it now on-demand.