Industry Use Cases for Kubernetes / Openshift from RedHat
Kubernetes, also known as K8s, is an open-source system for automating deployment, scaling, and management of containerized applications.
What is Kubernetes?
Kubernetes is a portable, extensible, open-source platform for managing containerized workloads and services, that facilitates both declarative configuration and automation. It has a large, rapidly growing ecosystem. Kubernetes services, support, and tools are widely available.
The name Kubernetes originates from Greek, meaning helmsman or pilot. Google open-sourced the Kubernetes project in 2014. Kubernetes combines over 15 years of Google’s experience running production workloads at scale with best-of-breed ideas and practices from the community.
Going back in time
Let’s take a look at why Kubernetes is so useful by going back in time.
Traditional deployment era: Early on, organizations ran applications on physical servers. There was no way to define resource boundaries for applications in a physical server, and this caused resource allocation issues. For example, if multiple applications run on a physical server, there can be instances where one application would take up most of the resources, and as a result, the other applications would underperform. A solution for this would be to run each application on a different physical server. But this did not scale as resources were underutilized, and it was expensive for organizations to maintain many physical servers.
Virtualized deployment era: As a solution, virtualization was introduced. It allows you to run multiple Virtual Machines (VMs) on a single physical server’s CPU. Virtualization allows applications to be isolated between VMs and provides a level of security as the information of one application cannot be freely accessed by another application.
Virtualization allows better utilization of resources in a physical server and allows better scalability because an application can be added or updated easily, reduces hardware costs, and much more. With virtualization, you can present a set of physical resources as a cluster of disposable virtual machines.
Each VM is a full machine running all the components, including its own operating system, on top of the virtualized hardware.
Container deployment era: Containers are similar to VMs, but they have relaxed isolation properties to share the Operating System (OS) among the applications. Therefore, containers are considered lightweight. Similar to a VM, a container has its own filesystem, the share of CPU, memory, process space, and more. As they are decoupled from the underlying infrastructure, they are portable across clouds and OS distributions.
Containers have become popular because they provide extra benefits, such as:
- Agile application creation and deployment: Increased ease and efficiency of container image creation compared to VM image use.
- Continuous development, integration, and deployment: Provides for reliable and frequent container image build and deployment with quick and efficient rollbacks (due to image immutability).
- Dev and Ops separation of concerns: Create application container images at build/release time rather than deployment time, thereby decoupling applications from infrastructure.
- Observability Not only surfaces OS-level information and metrics, but also application health and other signals.
- Environmental consistency across development, testing, and production: Runs the same on a laptop as it does in the cloud.
- Cloud and OS distribution portability: Runs on Ubuntu, RHEL, CoreOS, on-premises, on major public clouds, and anywhere else.
- Application-centric management: Raises the level of abstraction from running an OS on virtual hardware to running an application on an OS using logical resources.
- Loosely coupled, distributed, elastic, liberated micro-services: Applications are broken into smaller, independent pieces and can be deployed and managed dynamically — not a monolithic stack running on one big single-purpose machine.
- Resource isolation: predictable application performance.
- Resource utilization: High efficiency and density.
Why you need Kubernetes and what it can do
Containers are a good way to bundle and run your applications. In a production environment, you need to manage the containers that run the applications and ensure that there is no downtime. For example, if a container goes down, another container needs to start. Wouldn’t it be easier if this behavior was handled by a system?
That’s how Kubernetes comes to the rescue! Kubernetes provides you with a framework to run distributed systems resiliently. It takes care of scaling and failover for your application, provides deployment patterns, and more. For example, Kubernetes can easily manage a canary deployment for your system.
Kubernetes provides you with:
- Service discovery and load balancing Kubernetes can expose a container using the DNS name or using their own IP address. If traffic to a container is high, Kubernetes is able to load balance and distribute the network traffic so that the deployment is stable.
- Storage orchestration Kubernetes allows you to automatically mount a storage system of your choice, such as local storage, public cloud providers, and more.
- Automated rollouts and rollbacks You can describe the desired state for your deployed containers using Kubernetes, and it can change the actual state to the desired state at a controlled rate. For example, you can automate Kubernetes to create new containers for your deployment, remove existing containers and adopt all their resources to the new container.
- Automatic bin packing You provide Kubernetes with a cluster of nodes that it can use to run containerized tasks. You tell Kubernetes how much CPU and memory (RAM) each container needs. Kubernetes can fit containers onto your nodes to make the best use of your resources.
- Self-healing Kubernetes restarts containers that fail, replaces containers, kills containers that don’t respond to your user-defined health check, and doesn’t advertise them to clients until they are ready to serve.
- Secret and configuration management Kubernetes let you store and manage sensitive information, such as passwords, OAuth tokens, and SSH keys. You can deploy and update secrets and application configuration without rebuilding your container images, and without exposing secrets in your stack configuration.
What Kubernetes is not
Kubernetes is not a traditional, all-inclusive PaaS (Platform as a Service) system. Since Kubernetes operates at the container level rather than at the hardware level, it provides some generally applicable features common to PaaS offerings, such as deployment, scaling, load balancing, and lets users integrate their logging, monitoring, and alerting solutions. However, Kubernetes is not monolithic, and these default solutions are optional and pluggable. Kubernetes provides the building blocks for building developer platforms but preserves user choice and flexibility where it is important.
- Does not limit the types of applications supported.
- Do not deploy source code and do not build your application.
- Does not provide application-level services, such as middleware (for example, message buses), data-processing frameworks (for example, Spark), databases (for example, MySQL), caches, nor cluster storage systems (for example, Ceph) as built-in services.
- Does not dictate logging, monitoring, or alerting solutions.
- Does not provide nor mandate a configuration language/system (for example, Jsonnet).
- Does not provide nor adopt any comprehensive machine configuration, maintenance, management, or self-healing systems.
What is OpenShift?
OpenShift is a family of containerization software offerings created by open-source software provider Red Hat. According to the company, Kubernetes is the kernel of distributed systems, while OpenShift is the distribution. At its core, OpenShift is a cloud-based Kubernetes container platform that’s considered both containerization software and a platform-as-a-service (PaaS). It’s also partly built on Docker, another popular containerization platform. OpenShift offers consistent security, built-in monitoring, centralized policy management, and compatibility with Kubernetes container workloads. It’s fast, enables self-service provisioning, and integrates with a variety of tools. In other words, there’s no vendor lock-in. Previously known as Origin, the open-source platform, OpenShift OKD lets developers create, test, and deploy applications on the cloud. It also supports several programming languages, including Go, Node.js, Ruby, Python, PHP, Perl, and Java.
Kubernetes Vs. OpenShift
Both Kubernetes and OpenShift feature robust and scalable architecture that enables rapid and large-scale application development, deployment, and management. They both run on the Apache License 2.0. But that’s just about where the similarities end. Here are just a few of the many ways OpenShift and Kubernetes differ.
Kubernetes offers more flexibility as an open-source framework and can be installed on almost any platform — like Microsoft Azure and AWS — as well as any Linux distribution, including Ubuntu and Debian. OpenShift, on the other hand, requires Red Hat’s proprietary Red Hat Enterprise Linux Atomic Host (RHELAH), Fedora, or CentOS. This narrows options for many businesses, especially if they’re not already using these platforms.
OpenShift has stricter security policies. For instance, it is forbidden to run a container as a root. It also offers a secure-by-default option to enhance security. Kubernetes doesn’t come with built-in authentication or authorization capabilities, so developers must create bearer tokens and other authentication procedures manually.
Kubernetes has a large active community of developers who continuously collaborate on refining the platform. It also offers support for multiple frameworks and languages. OpenShift has a much smaller support community that is limited primarily to Red Hat developers.
Releases and Updates
Kubernetes has an average of four releases each year, while OpenShift trails with around three. Similarly, Kubernetes supports several concurrent and simultaneous updates, while OpenShift DeploymentConfig does not.
Kubernetes lacks a networking solution but lets users employ third-party network plug-ins. OpenShift, on the other hand, has its out-of-the-box networking solution called Open vSwitch, which comes with three native plug-ins.
Kubernetes offers Helm templates that are easy to use and provide a generous amount of flexibility. OpenShift templates are nowhere near as flexible or user-friendly.
Container Image Management
OpenShift lets developers use Image Streams to manage container images, while Kubernetes doesn’t offer container image management features.
Kubernetes User Case Studies -
( Reference Link: https://kubernetes.io/case-studies/ )
Openshift User Case Studies -
Both Kubernetes and OpenShift enable you to easily deploy and manage containerized applications. However, they have some differences. Kubernetes installation is complex and often requires a third-party solution. OpenShift has a built-in Kubernetes platform, which makes the installation process easier, but limited to Red Hat Linux distributions.
Hopefully, this article helped you understand the main differences between OpenShift and Kubernetes. When choosing a platform, you should consider your skillset and specs. The goal is to design the pipeline that works best for you, so be sure to experiment and check out the solution before adding the tool to your workflow.
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