Guest post originally published on the Snapt blog by Dave Blakey
Kubernetes is a popular tool for container orchestration. But why are so many companies choosing to use Kubernetes, and what benefit does it offer software development and DevOps teams?
This article will look at why so many teams choose Kubernetes and why it might be a good fit for you.
Why Use Kubernetes
Build Modular Applications For Easier Management
Building applications in containers with an abstraction layer encourages a modular approach that enables faster development by smaller teams.
When you design an application for deployment in containers, you can decompose the application into smaller parts. You can isolate dependencies and use smaller components optimized for specific functions.
However, containers by themselves are not enough for you to deploy and manage a module containerized application. You need a system for integrating and orchestrating these modular parts.
This is where a container orchestration tool such as Kubernetes comes in. Kubernetes achieves this using Pods and Services.
What are Kubernetes Pods?
A Pod is typically a collection of containers controlled as a single application. The containers in a pod share resources such as file systems, kernel namespaces, and an IP address. By sharing resources in a pod, Kubernetes doesn’t need to store too much functionality in each container image resulting in easier distribution and more efficient container sizes.
What are Kubernetes Services?
A Service is a collection of Pods that perform a similar function. Kubernetes users can configure Servicecs for easy discoverability, observability, horizontal scaling, and load balancing.
Deploy and Update Software At Scale
The DevOps method speeds up the process of building, testing and releasing software. The popularity of DevOps has shifted the emphasis from managing infrastructure to managing how software is deployed and updated at scale. Most infrastructure frameworks don’t support this model, but Kubernetes does – partly through Kubernetes Controllers.
Kubernetes uses a Deployment Controller to simplify complex management tasks, for example:
- Scalability. Scale out across Pods. Scale in or out at any time. Learn more about how to design scalable applications.
- Visibility. Identify completed, in-process, and failing deployments with status querying capabilities.
- Time saving. Pause a deployment at any time and resume it later.
- Version control. Update deployed Pods with newer versions of application images. Roll back to an earlier deployment if the current version is not stable or no longer suitable.
Kubernetes simplifies a few specific deployment operations that are especially valuable to developers of modern applications, for example:
- Horizontal autoscaling. Kubernetes uses autoscalers to automatically set the number of Pods in a deployment. Kubernetes triggers autoscaling by monitoring the usage of specified resources (within defined limits).
- Rolling updates. Kubernetes orchestrates rolling updates across a deployment’s Pods. Users can optionally set limits on the number of Pods that may be unavailable and the number of spare Pods that may exist temporarily during rolling updates.
- Canary deployments. Users can test new versions in production using the canary deployment pattern in Kubernetes. Canary deployments test a new version on a small audience segment in parallel with the previous version; if stable, the new version scales up and the old version scales down. Learn more about load balancing in canary and blue-green deployments.
Simplify Diverse Infrastructure
Kubernetes helps developers navigate the complexity of building and deploying applications in multiple environments and for multiple device types, operating systems, and configurations.
Applications depend on each environment’s specifics: the more environments, the more dependencies developers have to deal with.
- Your network architectures determine your performance.
- The constructs of each cloud provider determine orchestration techniques.
- Different back-end storage systems determine security and reliability.
It is expensive to maintain complete test environments that cater to these options. Using a container orchestration tool like Kubernetes, you can spawn different container types that cater to each scenario. You can automate and orchestrate container deployment for multiple environments making it cheaper and faster to meet the needs of each environment.
Kubernetes makes developers less dependent on specific networking requirements that significantly impact software development. Kubernetes provides core capabilities for containers with native features such as Pods and Services, removing restrictions and infrastructure lock-in.
Is Kubernetes the best container orchestration?
Given the popularity of containers, it is perhaps not surprising that many platforms try to solve the same problems that Kubernetes does. Kubernetes has many competitors in container orchestration.
Kubernetes Competitors
Each Kubernetes competitor has its merits and is worth looking into if you need container orchestration.
- Docker Swarm
- AWS EC2 Container Service (ECS)
- Apache Mesos with Marathon
- HashiCorp’s Nomad.
Kubernetes vs Docker Swarm and the rest
- Docker Swarm is bundled tightly with the Docker runtime so users can transition easily from Docker to Swarm.
- AWS users can access AWS ECS easier than Kubernetes.
- Mesos with Marathon is not limited to containers but can deploy any kind of application.
What makes Kubernetes different?
What makes Kubernetes different is that its clusters can run on AWS, Azure, and Google services, while also spanning internal servers.
Kubernetes has an advantage over other container orchestration platforms because it supports a wide range of application types. If an application can run in a container, it should run well on Kubernetes.
Kubernetes doesn’t dictate application frameworks, restrict the supported language runtimes, cater to only 12-factor applications, or distinguish “apps” from “services.” Kubernetes supports a wide variety of workloads, including stateless, stateful, and data-processing workloads, which means it is suitable for every type of application a large organization might need.
Great flexibility allows Kubernetes users to keep pace with the requirements of modern software development. Without Kubernetes, teams are often forced to script their own software deployment, scaling, and update workflows. Some organizations employ large teams to handle those tasks alone. Kubernetes allows us to get the most from containers and build cloud-native applications that can run anywhere, independent of cloud-specific requirements. Platform-agnostic and cloud-neutral deployment is something developers have been waiting a long time for.
Why is Kubernetes so complicated?
Kubernetes is often accused of being complicated. However, complicated application infrastructure doesn’t necessarily mean a more complicated deployment workflow overall – and that’s the balance Kubernetes attempts to strike.
Kubernetes moves the complexity from the applications into the application infrastructure. It handles things like logging, redundancy, scaling, and security – functions that would otherwise be built into every application. With Kubernetes managing much of the complexity at the infrastructure level, your applications can be simpler, leading to faster development and easier maintenance.
Snapt Nova provides dynamic load balancing and security on-demand for your Kubernetes ingress in public cloud, massively reducing the complexity of managing this critical interface. Read our datasheet to learn more about Snapt Nova and Kubernetes.
Should I Use Kubernetes?
As always, it depends. If you build and deploy monolithic applications and you have no plan to change this, Kubernetes will bring you no benefits. If you cannot afford the cost of adopting a new architecture and platform, or the costs associated with learning a new framework and the skills to go with it, Kubernetes might not be right for you.
However, if you currently build applications in containers, or you are planning to, and you intend to deploy and manage these applications at scale, then you ought to consider container orchestration.
Kubernetes is a popular choice because of its flexibility, open source, and wide community support.
If you need a platform with more vertical integration or in-house enterprise support, you might consider one of the alternatives.
Conclusion
It’s clear that containers are the future of application deployment. Teams that choose the right tools will capitalize on the opportunity presented by cloud-native development. And while we’re not proposing that Kubernetes is the solution for every problem – there is a reason why it is proving so popular with development and DevOps teams.