Understanding OpenShift Architecture: A Beginner’s Guide

If you’ve been around the DevOps or cloud-native world, you’ve probably heard of OpenShift. It often comes up in conversations about Kubernetes, containers, and enterprise-ready cloud platforms. But what exactly is OpenShift, and how does its architecture work?

In this beginner’s guide, we’ll break down OpenShift’s architecture step by step. By the end, you’ll have a clear picture of how OpenShift is structured and why it’s such a powerful platform for modern application deployment.

What is OpenShift?

OpenShift is a Platform-as-a-Service (PaaS) built on Kubernetes, designed to make deploying, managing, and scaling containerized applications simpler and more efficient. It adds developer-friendly tools, enterprise-grade security, and operational consistency on top of Kubernetes, making it ideal for production environments.

Key Features:

• Enterprise-grade Kubernetes: Offers a stable, secure, and fully supported Kubernetes environment for reliable operations.

• Developer productivity tools: Integrated CI/CD pipelines, Source-to-Image (S2I) builds, and intuitive developer consoles accelerate application delivery.

• Security and governance: Built-in Role-Based Access Control (RBAC), Security Context Constraints (SCCs), and network policies ensure enterprise-grade security.

• Operators: Automate deployment, scaling, and management of applications and infrastructure, reducing operational overhead.

How OpenShift Differs from Vanilla Kubernetes

Unlike vanilla Kubernetes, OpenShift is opinionated and ready to use. It comes with pre-integrated tools, strict security defaults, and enterprise support, providing a production-ready platform that bridges the gap between development and operations.

Core Components of OpenShift Architecture

OpenShift’s architecture is layered, combining Kubernetes’ core functionality with enterprise-grade enhancements. Understanding these layers helps you see how OpenShift manages applications efficiently.

1. Infrastructure Layer

OpenShift can run on a variety of environments:

• Bare metal servers
• Virtual machines
• Public cloud providers (AWS, Azure, GCP)
• Private clouds (OpenStack)

Clusters consist of two main types of nodes:

• Master nodes (Control Plane nodes): Manage the cluster, maintain overall state, and handle scheduling and orchestration.

• Worker nodes: Run the containerized applications and workloads.

This separation ensures scalability, reliability, and efficient resource management.

2. Control Plane

The control plane is the brain of the cluster, responsible for maintaining the desired state of applications and infrastructure. Key components include:

• API Server: The main entry point for all cluster operations, handling REST API requests.

• Controller Manager: Continuously monitors the cluster to ensure the actual state matches the desired state.

• Scheduler: Decides which nodes will run each pod based on available resources and policies.

• etcd: A distributed key-value store that holds all cluster configuration data and state.

OpenShift also extends the control plane with additional services, such as the OAuth API Server for authentication and specialized controllers for OpenShift-specific resources.

3. Node Components

Each worker node runs essential services to manage workloads:

• Kubelet: Ensures containers are running as defined in their specifications.

• CRI-O: Lightweight container runtime optimized for Kubernetes and OpenShift.

• Kube-proxy: Manages networking, load balancing, and communication between pods and services.

These components allow nodes to function autonomously while staying connected to the cluster.

4. OpenShift-Specific Enhancements

OpenShift builds on Kubernetes by adding enterprise-ready features:

• Operators: Automate deployment, scaling, and management of applications and infrastructure.

• Projects/Namespaces: Provide multi-tenancy and resource isolation for teams or departments.

• Source-to-Image (S2I): Builds container images directly from source code, simplifying the development-to-deployment process.

• Integrated CI/CD: Supports Jenkins and Tekton pipelines for automated build, test, and deployment workflows.

• Image Registry: Manages container images internally, ensuring consistency and security across the cluster.

• Routes: Simplify exposing applications to the outside world by mapping internal services to external hosts – no need to deal with complex ingress configurations.

These enhancements make OpenShift a full enterprise-grade container platform.

OpenShift Deployment Models

OpenShift is flexible and supports various deployment models:

• OpenShift Container Platform: Self-managed on-premises or cloud.

• OpenShift Dedicated: Managed by Red Hat on cloud platforms.

• Red Hat OpenShift Service on AWS (ROSA): Fully managed OpenShift on AWS.

• Azure Red Hat OpenShift (ARO): Fully managed OpenShift on Azure.

• OKD: Community distribution of Kubernetes that powers OpenShift.

At Ksolves, we provide end-to-end OpenShift consulting services, guiding businesses in selecting the ideal deployment model and implementing OpenShift with precision. Whether it’s an on-premises setup or a fully managed cloud deployment, our experts ensure your OpenShift environment is secure, highly scalable, and optimized for performance.

Networking in OpenShift

Networking is a critical part of OpenShift, enabling pods, services, and applications to communicate securely and efficiently. OpenShift uses Software Defined Networking (SDN) to manage cluster networking in a flexible and scalable way.

Key Networking Components:

• OpenShift SDN: Creates overlay networks that allow pods to communicate seamlessly across nodes, abstracting the underlying infrastructure.

• Services: Provide stable internal endpoints for pods, enabling communication without needing to know pod IP addresses.

• Routes: Expose applications to external traffic, making them accessible outside the cluster.

• Ingress: Manages external access to services, typically through a highly available load balancer like HAProxy.

This layered networking approach ensures that applications in OpenShift can communicate reliably, scale effortlessly, and remain secure across private or public cloud environments.

Security & Governance

Security is a core strength of OpenShift, ensuring that applications and infrastructure remain protected while meeting enterprise compliance requirements. OpenShift integrates multiple layers of security controls to safeguard workloads and manage access effectively.

Key Security Features:

• Role-Based Access Control (RBAC): Enables fine-grained access management by assigning roles and permissions to users and groups, ensuring that only authorized individuals can perform specific actions.
• Security Context Constraints (SCCs): Define what actions pods and containers can perform, such as restricting root privileges, enforcing filesystem access policies, and controlling capabilities.

• Network Policies: Regulate pod-to-pod communication within the cluster, allowing secure segmentation of applications and preventing unauthorized access.

• Built-in Monitoring & Logging: Provides observability into cluster health, security events, and application behavior, enabling proactive detection and resolution of issues.

By combining these features, OpenShift offers a robust and enterprise-ready security framework that protects workloads, simplifies compliance, and gives teams confidence in managing production applications.

Advantages & Limitations

Let’s dive into the advantages and limitations of OpenShift. 

Advantages

• Enterprise-grade security and governance: Built-in RBAC, SCCs, and network policies ensure secure and compliant operations.

• Developer-friendly tools and workflows: Integrated CI/CD pipelines, S2I builds, and developer consoles accelerate application delivery.

• Hybrid and multi-cloud ready: Run workloads consistently across on-premises, private, and public cloud environments.

• Integrated CI/CD support: Simplifies automation of build, test, and deployment processes for faster time-to-market.

Limitations

• Steeper learning curve: OpenShift introduces additional concepts and tools beyond vanilla Kubernetes.

• Resource-intensive: Requires sufficient compute and storage resources for optimal performance.

• Licensing costs: Enterprise editions involve licensing fees, which should be considered for budget planning.

Despite these challenges, OpenShift’s robust features and enterprise capabilities make it a preferred choice for organizations looking to modernize their application deployment and Devops practices.

Conclusion 

OpenShift effectively bridges the gap between development and operations, delivering a secure, scalable, and consistent platform for deploying containerized applications. Whether you are new to Kubernetes or looking to optimize your DevOps workflows, OpenShift provides a robust, enterprise-ready ecosystem for building, deploying, and managing modern applications with confidence.

At Ksolves, we help businesses leverage OpenShift to its full potential. From consulting on the right deployment model to implementing and managing your OpenShift environment, our experts ensure your platform is secure, optimized, and tailored to your workloads.