OpenShift
| Company type | Suite of containerization solutions |
|---|---|
| Industry | Cloud computing, Containerization software |
| Founded | May 2011 |
| Founder | Red Hat |
Area served | Global |
| Products | OpenShift Container Platform, OKD, Red Hat OpenShift Online, OpenShift Dedicated, OpenShift Data Foundation, Red Hat OpenShift Database Access |
| Parent | Red Hat |
| Website | www |
OpenShift represents a suite of containerization solutions created by Red Hat. Its leading offering, the OpenShift Container Platform, is a hybrid cloud platform as a service that leverages Linux containers managed through Kubernetes, built on top of Red Hat Enterprise Linux. The platform is available in various forms: OKD functions as the upstream community edition (akin to Fedora's relationship with Red Hat Enterprise Linux). Deployment choices encompass self-hosted setups, cloud-native services such as ROSA (Red Hat OpenShift Service on AWS), ARO (Azure Red Hat OpenShift), and RHOIC (Red Hat OpenShift on IBM Cloud) across AWS, Azure, and IBM Cloud respectively. Additionally, OpenShift Online is offered as a software as a service, while OpenShift Dedicated provides a managed service option.
The OpenShift Console delivers tailored interfaces for developers and administrators. Administrator views facilitate container resource monitoring, user administration, and operator management. Developer perspectives concentrate on application-related resources within specific namespaces. Furthermore, OpenShift includes a command-line interface that extends Kubernetes’ CLI commands with additional capabilities.
History
OpenShift’s inception traces back to Red Hat’s acquisition of Makara, a PaaS provider specializing in Linux containers, in November 2010. Initially launched as proprietary software in May 2011, it transitioned to an open-source model by May 2012. Prior to version 3 (released June 2015), OpenShift relied on proprietary container and orchestration systems; from version 3 onwards, it adopted Docker containers alongside Kubernetes orchestration. Version 4 brought significant architectural updates, incorporating CRI-O for container runtime (utilizing Podman for pod handling) and Buildah for container image creation, thereby decreasing dependence on Docker exclusively.
Architecture
The fundamental difference between OpenShift and standard Kubernetes lies in the treatment of build artifacts, which OpenShift manages as native Kubernetes resources subject to standard lifecycle operations. The OpenShift client tool, oc, enhances Kubernetes’ kubectl by adding commands like "new-build" and "start-build" to directly manage build resources. OpenShift includes its own pod build mechanism called Source-to-Image (S2I), though this is gradually being supplanted by Tekton, a cloud-native pipeline system comparable to Jenkins.
Distinctive features separating OpenShift from Kubernetes include:
- An integrated image registry included by default in OpenShift installations.
- Specialized constructs such as ImageStreams, which act as references to container images linked with deployments, and Templates that streamline application deployment processes.
- The "new-app" command automatically tags all generated resources with an app label, simplifying resource tracking.
- While initially confined to Red Hat environments, OpenShift 4 expanded its compatibility by 2020 to include AWS, IBM Cloud, vSphere, and bare-metal platforms.
- DeploymentConfig represents OpenShift’s unique deployment strategy based on declarative logic, differing from Kubernetes’ controller-driven Deployments; however, starting with version 4.5, OpenShift is progressively adopting standard Deployments as the default approach.
- A built-in OperatorHub offers a graphical interface for discovering and installing Kubernetes Operators, featuring both Red Hat Certified and community-developed options.
With OpenShift version 4, strict operating system governance is enforced: control plane components operate on Red Hat CoreOS for optimized patching and upgrades, whereas compute nodes can run any Linux distribution or Windows.
OpenShift introduced the concept of routes serving as ingress points for cluster traffic—a feature later incorporated into Kubernetes ingress controllers.
The platform also bundles several tools enhancing observability and infrastructure management such as Prometheus, Fluentd, Vector, Loki, and Istio. Red Hat’s customized Istio distribution—Red Hat Service Mesh—originates from the Maistra project and integrates seamlessly within OpenShift’s open-source ecosystem.
OpenShift Container Platform
OpenShift Container Platform, previously known as OpenShift Enterprise, represents Red Hat’s private platform as a service solution designed for on-premises deployment. It focuses on application containers utilizing CRI-O, with orchestration and management handled through Kubernetes. This platform operates atop Red Hat Enterprise Linux and Red Hat Enterprise Linux CoreOS.
OKD
OKD, which was called OpenShift Origin until August 2018, serves as the upstream community project that forms the foundation for OpenShift Online, OpenShift Dedicated, and OpenShift Container Platform. It integrates Docker container packaging with Kubernetes cluster management alongside tools supporting application lifecycle and DevOps processes. As an open source application container platform, OKD’s complete source code is accessible under the Apache License (Version 2.0) on GitHub.
Red Hat OpenShift Online
Red Hat OpenShift Online (RHOO) is a public cloud service by Red Hat that facilitates application development and hosting on AWS and IBM Cloud infrastructures.
Initially, RHOO provided version 2 of the OKD project under the Apache License 2.0, featuring support for multiple programming languages, frameworks, and databases through pre-configured "cartridges" operating within resource-limited "gears." This setup included an API enabling developers to add components. However, this architecture was phased out in favor of OpenShift 3, which was discontinued for all users by late 2017.
OpenShift 3 is built on Kubernetes and supports any Docker container; nonetheless, OpenShift Online prohibits containers requiring root privileges.
Red Hat OpenShift 4 for IBM Z and IBM LinuxONE offers deployment options across on-premises, cloud, and hybrid environments.
OpenShift Dedicated
OpenShift Dedicated (OSD) is Red Hat’s managed private cluster service emphasizing application containers powered by Docker and orchestrated with Kubernetes. It is constructed on Red Hat Enterprise Linux and has been available since December 2016 through marketplaces such as Amazon Web Services (AWS), IBM Cloud, and Google Cloud Platform (GCP). An equivalent managed private cluster service exists on Microsoft Azure called Azure Red Hat OpenShift (ARO).
OpenShift Data Foundation
OpenShift Data Foundation (ODF) provides cloud-native storage solutions along with data management and protection capabilities for applications running on the OpenShift Container Platform across cloud-based, on-premises, and hybrid or multi-cloud setups.
OpenShift Database Access
Red Hat OpenShift Database Access (RHODA) allows administrators managing OpenShift Kubernetes environments to establish connections with database-as-a-service providers. RHODA functions as an add-on for OSD and Red Hat OpenShift Service on AWS (ROSA), initially offering alpha-level compatibility with MongoDB Atlas and Crunchy Bridge for PostgreSQL.