Kubernetes is an open-source platform that orchestrates the management, deployment, and scaling of applications in containers. You can also break down applications into microservices. Google released Kubernetes in mid-2014 as the open-sourced version of Borg, a large-scale internal cluster management system. Google also partnered with the Linux Foundation to form the Cloud Native Computing Foundation (CNCF). Soon after, Google handed Kubernetes over to the CNCF to manage the high-quality project.
Today, Kubernetes adoption expands far beyond developer communities. A VMware study found that 59% of respondents were running Kubernetes in production. Since its launch, demand has skyrocketed, growing 250% between 2016 and 2020. Why is this important? Keep reading to learn more.
How Does Kubernetes Work?
At the most basic level, Kubernetes automates managing, deploying, and scaling containerized applications on a cluster of physical or virtual servers. It also automates storage, logging, alerts, and network for every container. Thus, it’s easy to understand why its inherent flexibility and scalability make Kubernetes so popular.
Why does this matter?
In a business sense, Kubernetes makes it easier to develop and deploy applications more quickly. In addition, Kubernetes is highly portable and you can use it with varying IT infrastructures and environments. Kubernetes is not tied to specific infrastructures or runtimes. Yet, there are still essential questions to address concerning Kubernetes. In this article, we will share 10 things you need to know about Kubernetes.
1. Kubernetes Automates Containerized Deployment
When Docker launched Docker Swarm, many tech companies started using the platform for development and testing. Nonetheless, when using microservices, containers can grow to the millions over time — making it challenging to manage. However, Kubernetes is the leader in container orchestration and excels where Docker Swarm fails.
Kubernetes can assign a unique domain name to any new service with its built-in discovery feature. As a result, every service can receive detailed information on any service in the etcd.
Kubernetes also offers multiple deployment strategies for container applications to ensure flexibility. Moreover, it supports A/B tests using Canary deployment or staged releases. And it provides Prometheus-based monitoring, which is a pull-based system.
You can even employ Kubernetes to update data using a rolling strategy to mitigate downtime. Once Kubernetes activates new pods to manage traffic, it then shuts down the older versions.
Here’s the exciting part.
While you can use Kubernetes in almost any environment, it’s a powerhouse in multi-cloud and hybrid environments because it can streamline and orchestrate container management even in the most complex environments. Since Kubernetes comes with built-in fault tolerance, it can also scale deployments up and down quickly.
2. Kubernetes Displaced Docker Swarm, Mesos, and YARN
Before Kubernetes, there were other open-source cluster management systems, including:
- Apache Mesos
- Docker Swarm
- Apache Hadoop YARN
Previously, Docker Swarm was the leading container management platform. Mesos had a distinguished track record before Kubernetes’ release. However, Mesos’ backer Mesosphere eventually announced their support for Kubernetes. And Docker followed suit by incorporating Kubernetes’ support.
Dave Bartoletti, principal analyst and vice-president of Forrester, noted the change by stating, “Kubernetes has won the war for container orchestration dominance and should be at the heart of your microservices plans.”
How did Kubernetes leap so far ahead of Docker Swarm and Mesos? Well, the answer is multi-faceted. First, Mesos tried to solve too many issues, such as managing non-containerized applications and fine-grained resource allocation. Second, Docker Swarm does not come with as many features as out-of-the-box Kubernetes.
Also, Docker Swarm does not auto-scale containers or nodes, nor does it offer built-in load balancing support. As a result, Kubernetes’ development and adoption have been much more rapid. Why? Kubernetes supports all potential auto-scalers, including vertical scaling by utilizing the Vertical Pod Autoscaler and horizontal scaling with the Horizontal Pod Autoscaler. If you run Kubernetes in the cloud, you can auto-scale node clusters via the Cluster Autoscaler.
Docker Swarm also works with Docker containers, where Kubernetes can work with Docker, Rocket, ContainerD, and many others. Integrating a wide variety of containers is a vital feature since you no longer have a dependency on specific components.
3. Kubernetes Is Also Known As k8s
Why was Kubernetes shortened to k8s? Often, developers like to simplify communication by using numeronym forms:
- Using the first letter.
- Using numbers to represent the total letter count.
- Adding the last letter.
So, “K” stands for Kubernetes, there are eight letters in between, and it ends with an “S.”
4. Kubernetes Is Declarative
Declarative programming allows programmers to define what they need without listing commands for how it should execute. Kubernetes provides the ability to specify what should be deployed without requiring the how. Therefore, you can meet all declared requirements, including:
- How many instances to create
- How many volumes to mount
- A container image and its associated startup arguments
- Maximum and minimum resources for memory, CPU, and more.
- What types of credentials to load.
- Environment configuration and variables.
- Which ports to use for communication with other services.
In addition, Kubernetes uses YAML to specify declared requirements, so no coding is needed. Before Kubernetes and other similar container management systems, software devs had to write extensive code to declare conditions, also called infrastructure-as-code.
5. Kubernetes Container Orchestration Is an Enhanced Process
You can package an application, and all its dependencies, in a container. Organizations that use DevOps methodologies find value in using containers for consistency, portability, and efficiency in deploying applications.
What is orchestration? It’s a detailed description of automation. Kubernetes enhances the container orchestration process by handling all of the details. For example, it can manage how many containers to create or which containers to scale. It also administers memory and processor requirements for each container. Therefore, you don’t have to worry about which servers to use for running applications.
Kubernetes can auto-scale applications by considering resources used on each target server and each application’s resource requirements. So, Kubernetes prevents containers from running on overloaded servers automatically.
It all boils down to this.
Using anti-affinity policies, Kubernetes can launch containers of the same type on different servers. This is also referred to as a ReplicaSet, which maintains a defined set of Replica Pods at any given time. If you want seven containers of your eCommerce site, Kubernetes will continually maintain those seven containers.
Additionally, if a server is dead, Kubernetes will allocate the containers to another server. Using Kubernetes’ Container Runtime Interface (CRI), you can also plug in new container formats.
Since Kubernetes simplifies container management so effectively, many global tech companies have gotten behind the platform, including:
- Amazon Web Services
- Dell Technologies
6. It Is Open-Sourced
Outside of Linux, Kubernetes is the fastest-growing open-source project. According to Github, Kubernetes also has the most active open source community with over 388,100 comments on its repository.
Undoubtedly, there is a surge in demand for open-source platforms since they have more independence relative to software owned by one vendor.
And the best part:
If you want to outsource expertise to maintain your Kubernetes platform, you can easily do so without feeling locked into one partner solution. Moreover, you can find new features released consistently on the Kubernetes GitHub page.
7. Kubernetes Offers Support for Stateless and Stateful Applications
A stateless application depicts a functioning application that does not save data on previous operations. Each time a stateless application executes a new operation, it does so from scratch. In contrast, a stateful application can remember user actions, preferences, profiles, and more.
Initially, Kubernetes primarily supported stateless applications with limited stateful support. Today, Kubernetes now comes with the StatefulSet controller that depicts stateful applications as StatefulSet objects.
Kubernetes can also support many types of volumes, including block storages mounted to exclusive mode pods and file storages using the NFS protocol. Thus, you can add persistent message queues and databases with ease.
8. Kubernetes Is Self-Healing
Inevitably, software bugs, hardware issues, power outages, natural disasters, or upgrades can cause failures to occur. Yet, Kubernetes continues working because it views a failure as a deviation and nothing more.
How does Kubernetes self heal? It does so by replicating its state. It also sends health checks to nodes and containers to determine a healthy vs. unhealthy entity. If a container is unhealthy, Kubernetes will initiate a new version.
It makes sense that all major public cloud providers, such as AWS, Google, and Microsoft Azure, all support Kubernetes.
9. Kubernetes Is Extensible
As a system design principle, extensibility takes future growth into consideration either through adding new functionalities or updating existing ones. With Kubernetes, you can create customized resource types and operators to create growth-oriented specifications.
To illustrate, you can define resource and operator type to run a custom-state application on Kubernetes. In addition, Kubernetes resource types do not require much coding to compose.
10. Kubernetes Improves Productivity
Incorporating Kubernetes into your DevOps workflows can help to standardize testing and deployment workflows. It gets better: since the Kubernetes ecosystem is vast, engineering teams can create solutions by mitigating time-consuming and manual coding work. Further, most k8s tools are free to use and open-source.
Kubernetes’ key design objective is to simplify DevOps’ activities by automating and orchestrating application processes and services deployments–previously executed manually. Undeniably, Kubernetes stands miles apart from many other orchestration systems by incorporating features offering convenience, efficiency, and agility around container management.