Kubernetes is the leader in the container orchestration space and addresses many challenges related to scaling containerized workloads. However, at scale, Kubernetes cluster management can create challenges and complexities of its own. 

Today, several platforms address the challenges of Kubernetes management. SUSE’s Rancher and Red Hat’s OpenShift Container Platform (OCP) are two of the most popular. 

Rancher and OpenShift both make Kubernetes clusters easier to manage, but each platform has some notable differences. There’s no one-size-fits-all solution, and the right solution depends on an organization’s use case. 

In this article, we’ll take a closer look at Rancher vs. OpenShift, the similarities and differences between the platforms, and provide guidance on which platform makes the most sense for specific use cases.

What is Rancher?

Rancher Labs was founded in 2014. SUSE acquired Rancher in 2020 to bring Kubernetes into their portfolio. Rancher has three key products that integrate into the Kubernetes space:

• Rancher, a cluster manager
• Rancher Kubernetes Engine (RKE), a Kubernetes distribution that runs on Docker
• K3s, a lightweight version of Kubernetes.

The Rancher platform is a multi-cluster manager for Kubernetes. Rancher can manage clusters installed on-premise or in the cloud providing a centralized management console. Rancher can also import previously deployed Kubernetes clusters not initially deployed with Rancher.

One of the most significant points about Rancher is that it can manage multiple Kubernetes clusters in various locations regardless of whether or not they are created with Rancher. So if you already have a Kubernetes cluster, you can import it into Rancher and begin to manage it from Rancher’s interface.

This is an excellent option for those already using Kubernetes as Rancher itself is not a Kubernetes distribution but instead a management tool.

Both RKE and K3s are lighter-weight Kubernetes installs developed by Rancher that can be used on on-premise and single-node installs. RKE runs Kubernetes inside Docker containers, and K3s is a lightweight binary that installs the bare-minimum components on the systems.

What is OpenShift?

Red Hat’s OpenShift Container Platform is their product in the Kubernetes container orchestration space. OpenShift is a distribution of Kubernetes that adds on additional developer tooling, integrated registry management, and stricter security policies by default. Red Hat refers to this as an opinionated way of running Kubernetes.

The OpenShift Marketplace makes it easy to deploy certified software to your clusters. A marketplace instills more confidence that your add-ons will work with OpenShift.

While Rancher can manage multiple Kubernetes clusters out of the box, OpenShift requires the Advanced Cluster Management add-on to their support plan.

As both products are container orchestration platforms tied closely with Kubernetes, there are inherently many similarities. There are a few differences between the products. This article will use the differences to help frame use cases where you might want to pick one over the other.

Rancher vs. OpenShift Similarities

As Kubernetes management platforms, Rancher and OpenShift share many similarities. The table below lists key OpenShift and Rancher Kubernetes management features that are similar.

For all comparisons in this article, we used these versions as a baseline:

• Rancher 2.6
• K3s V1.24.2+k3s2
• RKD 1.3.12
• OCP 4.10

Rancher vs. OpenShift Similarities

Rancher vs. OpenShift Differences 

The differences between Rancher vs. OpenShift are often what determines which platform is best for a specific use case. The table below summarizes key Rancher vs. OpenShift differences. 

Rancher vs. OpenShift Differences

Rancher vs. OpenShift: Supported Operating Systems

Kubernetes requires an underlying operating system. Administrators can use full-featured Linux operating systems like Red Hat Enterprise Linux (RHEL), CentOS, SUSE Enterprise Linux, and Ubuntu to run Kubernetes. The benefit of using these operating systems stems from their popularity: administrators are often already comfortable managing them.

That makes it easy to handle operating system-level operations but comes with tradeoffs. For example, these general-purpose operating systems aren’t container-optimized.

A container-optimized operating system is geared towards running containers. Often, the root filesystem is read-only, and updates are applied via new images instead of a package manager. CoreOS, Google’s Container-Optimized OS, and AWS Bottlerocket are popular examples. 

Let us look at how Rancher and OpenShift approach the topic of base operating systems.

Rancher, RKE, and K3s

Rancher can be installed on most popular operating systems. In specific scenarios, the underlying operating system may need to meet specific requirements. For example, with RKE you only need a system that can run Docker. With K3s, you don’t need Docker.

OpenShift and CoreOS

OpenShift takes a different approach. CoreOS is the default and only supported host operating system for OpenShift. CoreOS is based on Red Hat Enterprise Linux (RHEL) and benefits from all of the security patches and package updates that Red Hat delivers.

CoreOS does not have a package manager or a way to update only part of the system. Instead, the host operating system upgrades are delivered via new images written to disk. A reboot will trigger the system to boot into the upgraded image. Dictating updates to CoreOS as part of the OpenShift upgrade process keeps the host systems updated and in line with OpenShift.

Rancher vs. OpenShift: Deployment & Upgrades

Installing and planning the upgrade path for your cluster is another area to consider when it comes to the differences between Rancher vs. OpenShift.

Both Rancher and OpenShift have the same goals of simple installation, support for multiple cloud providers, and resource efficiency to support edge computing.  However, they go about achieving these goals differently. 

Ultimately when using Rancher, you are deploying a Kubernetes cluster and using Rancher as the interface to manage it. The underlying install could be different with on-prem vs. cloud. With OpenShift, no matter where you install it, the underlying platform is the same. 

Rancher vs. OpenShift: Deployment & Upgrades

When to use Rancher vs. When to use OpenShift

Even after you understand the similarities and differences between Rancher vs. OpenShift. It is difficult to say one way is objectively better than the other. 

However, there are several use cases where one of the platforms is generally a better fit. Below, we’ll list those scenarios. 

Consider Rancher if…

• You are already using Kubernetes locally or on a primary cloud provider.
• You do not have requirements for the host operating system
• You need more flexibility in the different components of your cluster
• You want to make more decisions about the components of your cluster
• You have limited resources and can start small, i.e., a single node cluster

Consider OpenShift if…

• You are already familiar with Red Hat products or have a Red Hat Subscription
• You run applications that require certification on the operating system
• You want to run air-gapped installations
• You want to manage a private registry

Try It Out!

If you’re still undecided, both Rancher and OpenShift have versions that you can install and test on a single machine. 

Rancher Desktop / K3s

Getting Rancher installed and running a minimal Kubernetes cluster on your desktop is as easy as installing an application. Rancher Desktop streamlines the installation and configuration process and allows you to launch a Kubernetes cluster quickly. 

With Rancher desktop, you install a K3s deployment of Kubernetes. K3s are suited for installation on a single machine and even support production workloads.

Red Hat, Code Ready Containers (CRC), and OKD

Red Hat offers code-ready containers (CRC) for single-node testing. CRC versions are for testing and are not suitable for production.  You can download and learn more about CRC on the Red Hat Developer Website.

You can also use OKD to get a feel for what it’s like to use OpenShift. OKD is the upstream community platform from which OpenShift is built. This is where Rancher and OCP are a bit different. To get Red Hat’s support, you need to use OpenShift, built based on the corresponding version of OKD.

Conclusion

Deciding on the infrastructure to run your applications can be daunting. Nobody wants to make the “wrong” decision. Knowing your options and how they match your specific needs is always a crucial step. 

This article covered SUSE Rancher and Red Hat’s OpenShift overall goals to make it easier to manage Kubernetes clusters. Both of them back their products with professional support.

It is worth highlighting again that Rancher is Kubernetes cluster manager. It can manage almost any CNCF-certified Kubernetes cluster. It uses CNCF-certified K3s for single-node, on-premise resource-limited installs.

OpenShift is also a CNCF-certified Kubernetes distribution, but Red Hat has made some opinionated choices on the different components, such as their ingress controller and other networking components.

Now that you understand the differences between these platforms, you can make a more informed decision about Kubernetes management at scale.