OpenShift vs. OpenStack

OpenShift and OpenStack are used to build scalable cloud platforms. When combined, the systems cover the entire range – from provisioning virtualised hardware to developing and operating containerised applications. OpenShift and OpenStack are popular with large, global organisations to implement hybrid cloud strategies.

Historically, OpenStack has been around longer than OpenShift. The evolution of the two projects is representative of the transition from virtual machines to application containers. Container virtualisation has become the dominant virtualisation technology over the past decade.

OpenShift and OpenStack are open-source projects that were created around 2010/2011. Both are used to build scalable systems in hybrid cloud environments. They are predominantly employed by large, global organisations and can be operated on a wide range of underlying computing infrastructures.

Both platforms could be seen as a type of ‘cloud operating system’. OpenShift is used to develop and operate containerised applications. Users can provide, operate, and monitor applications and services themselves, and focus on optimised development and DevOps workflows.

OpenStack, on the other hand, comes with a deeper level of abstraction. The platform is used to build a virtualised cloud infrastructure on the basis of distributed hardware. Virtual machines with CPU cores and RAM, as well as virtual networks and distributed mass storage are provisioned. Following the self-service model, users automatically request resources. Let’s take a look at how OpenShift vs. OpenStack are positioned in terms of their differences:

With OpenStack, organisations can build their own cloud environments following the infrastructure-as-a-Service (IaaS) model. An internal cloud similar to AWS and alternatives can be created. OpenStack relies on distributed hardware available through various interfaces as a cloud resource.

In contrast, OpenShift handles the centralised management of application development and operations. The software is based on Kubernetes (K8s) and controls K8s clusters across cloud boundaries. Following the Platform-as-a-Service (PaaS) model, system functions can be operated via a web interface.

Although their names sound similar, OpenShift and OpenStack are not related. They can be used independently. However, it is also possible to combine them. As part of a hybrid cloud strategy, OpenStack could be used to build a private cloud. OpenShift could then draw upon the resources contained within it to provide and manage applications and services. It is also possible to deploy OpenStack components on K8s or OpenShift clusters.

Let’s take a detailed look at the advantages and disadvantages of the two technologies, common deployment scenarios and differences and similarities.

OpenStack is an open platform to build scalable cloud environments. The software acts as a layer of abstraction on top of a decentralised hardware infrastructure. Its core functionality is the provision and allocation of computing, network, and mass storage capacities. Following the Infrastructure-as-a-Service (IaaS) model, users can request the resources they require. In addition to mandatory APIs, a web interface is available for managing the system.

Beyond resource provisioning, OpenStack offers other functions, including user identity management, DNS entry management, and a service to manage VM images. Conveniently, the individual functions are encapsulated as individual components. There are over three dozen components in the current OpenStack version; usually not all of them are used in a single project. We provide a brief overview of the most important components:

OpenStack helps organisations to build their own cloud infrastructure based on existing technology. This results in huge cost savings because they do not need to start from scratch. OpenStack consists of individual components, which are configured according to a company’s needs. It is an open-source software that is freely available. Development and documentation of the platform are predominantly driven by the OpenStack community.

Due to the complex nature of the software, installing OpenStack is considered challenging. The overall package includes a large number of individual components, which have to be configured individually. Documentation contributed by its community can lag behind its rapid development. Both of these disadvantages can be addressed by working with specialists or tech partners. Such services will likely incur additional costs. Since OpenStack is almost exclusively used for large-scale projects, users should budget accordingly.

OpenStack is best suited for building cloud infrastructure on decentralised computing hardware. The software performs extremely well when it comes to virtual machines (VM). In combination with OpenShift or comparable K8s management solutions, VM and container-based applications can be operated side by side. Container virtualisation with the ‘Magnum’ component now forms part of its range of native functions.

OpenShift is used to building distributed, scaling application and development environments based on the Platform-as-a-Service (PaaS) model. The software provides a complete execution environment in which containers are deployed, executed, managed, and orchestrated. The integrated tools simplify modern development and deployment workflows.

As a substructure, OpenShift uses a special Kubernetes (K8s) distribution. This can be deployed across cloud and infrastructure boundaries, achieving a consistent user experience. The K8s core functionality is complemented by security and monitoring features and is based on centralised policy management. This ensures a high-quality standard across the software landscape of an entire organisation. For the most part, OpenShift operators are used for implementation:

OpenShift eases the operational complexity associated with administering self-managed K8s clusters. Multiple K8s clusters can be centrally managed across public and private cloud infrastructures. Following the PaaS approach, developers can request resources for their projects via a web interface. Integrated tools and workflows for continuous integration and continuous delivery (CI/CD) also form part of its portfolio of functions. This results in drastically reduced delivery times.

OpenShift convinces with its integrated security measures. ‘Quay’ is its specially secured container registry. End-to-end authorisation and authentication limits user access to the individual areas of the system. The ability to host individual clusters in different geographic regions makes for better compliance in terms of data protection and data sovereignty.

OpenShift only runs on special operating systems from Red Hat, such as ‘Red Hat Enterprise Linux CoreOS’ (RHCOS) and ‘Red Hat Enterprise Linux’ (RHEL). The installation is considered extremely complex. For example, the setup for larger projects can take several weeks. Due to the strict security precautions, specially secured container images from Red Hat's ‘Quay’ container registry are used.

On the basis of OpenShift, a business’s Platform-as-a-Service (PaaS), Software-as-a-Service (SaaS) and Container-as-a-Service (CaaS) solutions can be implemented. Clearly, OpenShift is geared towards large organisations and is too complex for individual developers to deal with.