OpenShift alternatives

OpenShift is the leading development platform for containerised applications based on Kubernetes. A growing number of companies are using Kubernetes as a cluster manager as a basis for operating and developing containerised applications and services. In other words, Kubernetes is a distributed operating system for modern, container-based development.

The OpenShift platform was released by Red Hat – the maker of the professional Linux distribution ‘Red Hat Enterprise Linux’ (RHEL). The OpenShift alternative ‘Rancher’ has now been taken over by the traditional Linux provider SUSE. ‘Canonical Kubernetes’, is another OpenShift alternative from an established Linux provider. Read on to find out more about these and other alternatives to OpenShift.

OpenShift is a powerful system that combines a variety of functionalities. In addition to Kubernetes management, it includes a dashboard to visualise clusters. Tools for monitoring and logging, DevOps pipelines and a service mesh round out its functions that make it easy to set up distributed applications and services. In summary, OpenShift and its alternatives are Kubernetes management solutions.

Kubernetes are the common feature of OpenShift and its alternatives. But their functions extend far beyond managing containerised applications. In contrast to bare Kubernetes, OpenShift and alternatives control deployment and operation of distributed Kubernetes clusters across the cloud and other infrastructures. Thanks to user end-to-end authentication and deployment of container images the systems are secure.

Our comparison does not include independent alternatives to Kubernetes such as ‘Apache Mesos’ and ‘Azk’. These are described in our article on Kubernetes alternatives. Furthermore, we shall not dive into Kubernetes-as-a-Service (KaaS) offerings from major cloud providers. These can only be used as part of a cloud infrastructure of the respective provider, for example:

• IONOS Cloud Managed Kubernetes
• Google Kubernetes Engine (GKE)
• Amazon Elastic Kubernetes Service (EKS)
• Azure Kubernetes Service (AKS)
• IBM Cloud Kubernetes Service (IKS)

Kubernetes achieves a previously unattainable level of automation. However, Kubernetes is a highly complex technology. Not all organisations have the experience and capacity to run their own Kubernetes infrastructure. A ‘fully-managed’ Kubernetes cluster, also known as ‘Kubernetes-as-a-Service’ (KaaS) solves the problem: the provider manages a Kubernetes cluster for the client in the provider's cloud environment. This allows the client to focus entirely on their core business.

A Kubernetes management solution is a management layer based on Kubernetes. Beyond container orchestration, the complete lifecycle of containerised applications can be managed. The Kubernetes clusters used can be hosted on virtually any infrastructure, from the public cloud to the company's own OpenStack environment to ‘bare metal’ and edge devices. For the user, this creates functionality beyond Kubernetes without tying the system to a specific infrastructure provider.

For the purpose of comparison, we differentiate between fully-managed and self-managed solutions. Some OpenShift alternatives are available only as managed solutions. However, all enable operation of work clusters across infrastructure boundaries.

The development of Kubernetes management solutions is in constant flux. Even though OpenShift alternatives have similar functions, they often differ in the details. We summarise the most important features in the table below:

Below you’ll find a brief overview of OpenShift and select leading alternatives. In each case, we address the advantages and disadvantages of the alternative, their main differences compared with OpenShift, and common deployment scenarios. The following Kubernetes Management Solutions are compared:

• Red Hat OpenShift
• SUSE Rancher
• Canonical Kubernetes
• Mirantis Kubernetes Engine (previously Docker Enterprise)
• VMware Tanzu (previously Pivotal)
• Platform9 Managed Kubernetes
• Giant Swarm
• Portainer

OpenShift is the frontrunner of Kubernetes Management Solutions created by Red Hat. The software is used to build distributed, scaling application and development environments. Since the early days of Kubernetes, Red Hat has contributed considerably to the development of the technology.

The biggest advantage of OpenShift is the system’s range of functions. In addition to cluster management, technologies for the complete management of the application lifecycle are integrated, including development, rollout, operation, and maintenance. Furthermore, Red Hat provides its own container registries, as well as a catalogue of operators.

The large feature set of OpenShift increases the complexity of the software. Installing and maintaining OpenShift requires a team of experts, or support as part of a managed solution. To make matters worse, OpenShift’s Kubernetes distribution differs significantly from the upstream version. Furthermore, OpenShift only runs on Red Hat’s own operating system, Red Hat Enterprise Linux CoreOS (RHCOS).

OpenShift is also special in terms of the container images used. Due to the strict security settings, not all images from the freely available repositories can be used. Instead of the Helm charts known from Kubernetes, OpenShift uses proprietary application templates to build the infrastructure. However, as of the launch of powerful OpenShift operators, an alternative mechanism now exists.

OpenShift is particularly suitable for implementing hybrid cloud strategies and building and scaling the containerised applications required. Organisations that are already part of the Red Hat ecosystem will benefit from using the software.

Rancher is a long-standing OpenShift alternative that was acquired by SUSE at the end of 2020. Rancher provides a powerful yet flexible Kubernetes management platform. The software facilitates management of multiple Kubernetes clusters across different cloud environments. Range of functions includes provisioning, monitoring, and logging.

Besides the obligatory cluster management, Rancher integrates a number of interesting technologies. For example, the ‘Rancher Kubernetes Engine’ (RKE) is a Kubernetes distribution that is published as open source. It offers a minimal K3s distribution for use on edge and IoT devices. This can also be used to implement single node clusters. Rancher features access controls according to the ‘Open Policy Agency’ (OPA) standard and supports the ‘Longhorn’ storage engine.

Rancher is particularly well suited for managing multiple Kubernetes clusters with a centralised interface. User rights can be assigned centrally across multiple clusters.

Canonical Kubernetes is another Kubernetes management solution from a well-known operating system provider. Ubuntu Linux, developed by Canonical, serves as the foundation for Kubernetes distributions from major cloud providers such as Google Kubernetes Engine (GKE), Amazon Elastic Kubernetes Service (EKS), and Azure Kubernetes Service (AKS). Thus, with Canonical Kubernetes, users can build clusters that span cloud boundaries.

The biggest advantages of Canonical Kubernetes are flexibility and low cost of deployment. ‘Charmed Kubernetes’ is an exciting operator-based approach to build infrastructures. ‘Charms’ is a collection to seamlessly integrate and manage Kubernetes, container and VM-based applications across hybrid cloud environments. Canonical Kubernetes uses Ubuntu as operating system.

Canonical Kubernetes is suitable for a wide range of hardware. Processor architectures x86, ARM, IBM POWER, and IBM Z are supported; GPUs can be used in addition to CPU. For use on desktop and edge devices, there is the minimal ‘MicroK8s’ Kubernetes distribution, which is particularly resource-efficient.

Mirantis purchased ‘Docker Enterprise Edition’ from Docker Inc. in 2019, and since then the technology has been relaunched as ‘Mirantis Kubernetes Engine’. The software is rooted in the Docker universe. In addition to Kubernetes, Docker Swarm is a supported cluster manager.

The Mirantis Kubernetes Engine occupies an interesting niche. For example, in addition to Linux, it also supports Windows to run on nodes. Interestingly, Linux and Windows nodes can be mixed seamlessly, and the same applies to nodes with Kubernetes or Docker Swarm. The product is aimed at larger businesses. Thus, it unfortunately lacks a vibrant community of developers and the free trial version requires registration.

The technology is particularly suitable for larger organisations with a strong focus on the developer experience. If an infrastructure based on Docker Swarm or Windows nodes already exists, it is relatively easy to extend it with Kubernetes using the Mirantis Kubernetes Engine.

VMware Tanzu is a Kubernetes platform from virtualisation specialist VMware. The product resulted from the acquisition of Pivotal by VMware at the end of 2019. With VMware Tanzu, Kubernetes clusters can be built on VMware’s vSphere infrastructure. The integrated ‘Tanzu Mission Control’ is a centralised interface for managing distributed Kubernetes clusters. In addition to functionalities for development and operation of containerised applications, monitoring and logging, network and storage management are included.

The advantages of VMware Tanzu are primarily its integrated tools. The ‘VMware Tanzu Application Catalog’ contains a well-maintained catalogue of open source components and applications while ‘Harbor’ is a dedicated container registry to secured different build artifacts by means of role-based access controls. The container images stored in Harbor are checked for security holes and vulnerabilities and marked as secure. The focus when using VMware Tanzu is clearly on the deployment of vSphere infrastructure. Support for other cloud platforms is less sophisticated.

VMware Tanzu is particularly suitable for companies that already know their way around the vSphere infrastructure. In addition to the commercial version, a free version is available for Linux, Windows and Mac – the ‘VMware Tanzu Community Edition’.

Platform9 was founded by former VMware engineers. The core concept of the platform is to run established open-source software like Kubernetes under a software-as-a-service (SaaS) model for customers. This makes it possible to centrally manage Kubernetes clusters distributed across different cloud environments. Platform9 takes over the maintenance of the Kubernetes installations, which reduces operational complexity on the customer side.

The biggest advantage of Platform9 is its ‘fully managed’ operating model. Clients no longer have to deal with operating system or Kubernetes updates. Other positive features are its clear pricing structure, extensive documentation, and a free trial version. Even though the web interface is a bit outdated, it includes plenty of standard features: the ‘Prometheus’ software continuously checks the health of clusters, and logs are collected and analysed centrally. Applications available in public Helm repositories can be installed without any problems.

As a special niche, Platform9 focuses on telecommunication service providers that unite large quantities of edge devices in Kubernetes clusters. Furthermore, the platform makes it possible to run ‘legacy’ apps based on virtual machines in parallel to modern, containerised applications.

Giant Swarm is a ‘fully-managed’ Kubernetes platform. The software takes over the management of the Kubernetes environment, irrespective of the type of underlying cloud infrastructure used. Clients can thus focus on applications and services run on Kubernetes. The management and worker clusters can be operated on Amazon AWS, Microsoft Azure or ‘on-premises’ as part of a client’s existing computing infrastructure.

The platform manages and optimises the entire lifecycle of containerised applications and is quickly deployable. Unlike OpenShift, a Giant Swarm installation can be set up within a day. Since an unmodified Kubernetes distribution is used, it is relatively easy to move parts of the infrastructure between cloud environments. This reduces the risk of vendor lock-in. On the negative side, it is noticeable that there is no uniform pricing model. Instead, the price is tailored according to the client’s needs.

Giant Swarm is particularly suitable for controlling distributed microservice architectures. This allows resilient, agile systems to be built and scaled. The software takes over the complex management of the underlying infrastructure.

Unlike the aforementioned OpenShift alternatives, Portainer follows a different concept. It is not a fully-managed platform or Kubernetes distribution of its own. Instead, it uses a graphical user interface that unifies the management of existing Kubernetes deployments. DevOps teams have the ability to centrally manage, configure, and secure multi-cluster environments. At the developer level, deployment, management, and troubleshooting of containerised applications is simplified.

The main advantage of Portainer is the flexibility of the software. In addition to Kubernetes, Docker Swarm and Docker can be used to manage clusters and containers. Portainer is based on open-source software and is offered in a freely available community version as well as a paid version with enterprise support. The software can be installed in cloud environments, on edge devices, or within a client’s existing computing infrastructure. Since Portainer is relatively new, the documentation leaves much to be desired.

Portainer is particularly suitable for centralising and unifying the management of existing cluster infrastructures. If Docker or Docker Swarm-based systems are used in addition to Kubernetes, they can be managed with ease.