# OpenShift Origin — Enterprise Kubernetes Platform by Red Hat

> OpenShift is Red Hat's Kubernetes distribution that adds developer workflows, built-in CI/CD, and operator-managed infrastructure on top of upstream Kubernetes.

## Install

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# OpenShift Origin — Enterprise Kubernetes Platform by Red Hat

## Quick Use
```bash
# Install the oc CLI
curl -LO https://mirror.openshift.com/pub/openshift-v4/clients/oc/latest/linux/oc.tar.gz
tar xzf oc.tar.gz && sudo mv oc /usr/local/bin/
# Log in to a cluster
oc login https://api.cluster.example.com:6443
# Create a new application from source
oc new-app https://github.com/sclorg/nodejs-ex
```

## Introduction
OpenShift Origin (now OKD, the community distribution of OpenShift) extends Kubernetes with opinionated defaults for enterprise use. It provides integrated image builds, a web console, role-based multi-tenancy, and operator-driven infrastructure management, reducing the operational burden of running Kubernetes in production.

## What OpenShift Does
- Provides a Kubernetes distribution with hardened security defaults (SELinux, SCC policies)
- Includes Source-to-Image (S2I) builds that compile code into container images without Dockerfiles
- Offers a rich web console for cluster management, monitoring, and developer self-service
- Manages infrastructure components via Operators and the Operator Lifecycle Manager (OLM)
- Supports multi-cluster management through Red Hat Advanced Cluster Management

## Architecture Overview
OpenShift runs a standard Kubernetes control plane (API server, etcd, controller-manager, scheduler) with additional components: the OpenShift API server for project/route management, an integrated OAuth server, the image registry operator, and the machine-config-operator for node OS management. CoreOS (or RHCOS) serves as the immutable node operating system managed declaratively.

## Self-Hosting & Configuration
- Deploy OKD (community version) on bare metal, AWS, GCP, Azure, or vSphere using the `openshift-install` CLI
- Minimum cluster requires 3 control plane and 2 worker nodes for high availability
- Configure via install-config.yaml specifying platform, networking (OVN-Kubernetes or OpenShift SDN), and machine pools
- Use `oc adm` commands or the web console for day-2 cluster administration
- Operators manage upgrades, certificate rotation, and component lifecycle automatically

## Key Features
- Routes provide built-in ingress with TLS termination without external ingress controllers
- Integrated CI/CD via OpenShift Pipelines (Tekton) and OpenShift GitOps (Argo CD)
- Security Context Constraints (SCCs) enforce pod-level security beyond standard PodSecurityPolicies
- Developer Catalog offers one-click deployment of databases, middleware, and application templates
- Serverless support through OpenShift Serverless (Knative)

## Comparison with Similar Tools
- **Vanilla Kubernetes** — OpenShift adds opinionated security, web console, and integrated builds
- **Rancher** — multi-cluster manager that works with any Kubernetes distribution
- **Tanzu** — VMware's Kubernetes platform, focused on vSphere integration
- **EKS/GKE/AKS** — managed cloud Kubernetes services without the self-hosted control plane
- **KubeSphere** — open-source multi-cluster platform with a similar feature scope

## FAQ
**Q: What is the difference between OpenShift and OKD?**
A: OKD is the upstream community distribution. Red Hat OpenShift Container Platform (OCP) is the commercially supported product built from OKD.

**Q: Can I run OpenShift on a single node?**
A: Yes. Single Node OpenShift (SNO) is supported for edge and small-footprint deployments.

**Q: Is OpenShift free to use?**
A: OKD is free and open source. Red Hat OpenShift requires a subscription for support and access to RHCOS and certified operators.

**Q: How does OpenShift handle upgrades?**
A: The Cluster Version Operator manages rolling upgrades of all control plane and worker components with minimal downtime.

## Sources
- https://github.com/openshift/origin
- https://docs.okd.io/

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Source: https://tokrepo.com/en/workflows/asset-40a5d5d9
Author: AI Open Source