Container adoption has accelerated rapidly, with orchestrators like Kubernetes and Red Hat OpenShift powering everything from cutting-edge microservices to legacy monoliths. But between the two, which should you choose to run your cloud-native applications?
This comprehensive overview compares the capabilities, architectures, strengths and weaknesses of Kubernetes vs OpenShift. I‘ll outline key decision factors so you can determine the best fit based on your environment, use case, and team. You‘ll leave with clear, actionable guidance on picking an enterprise-grade container platform.
An Introductory Overview
First, let‘s ground ourselves in what problems Kubernetes and OpenShift solve…
Running containerized apps at scale is incredibly complex. You need to coordinate networking, storage, scaling, failover and more across infrastructures.
That‘s where orchestrators come in. They provide automation and management to handle hundreds or thousands of containers across many hosts.
Kubernetes offers a flexible, open source orchestrator. It started at Google based on their Borg cluster manager and became a Cloud Native Computing Foundation project. Kubernetes powers some of the largest container deployments in the world.
OpenShift incorporates Kubernetes along with developer enhancements. Added by Red Hat, these aim to improve ease-of-use for IT teams getting started on containers. OpenShift adds deployments opinion and control guardrails.
In essence:
- Kubernetes priortizes extensibility and customizability
- OpenShift favors approachability and streamlined management
Over 28% of organizations now run Kubernetes in production, with rapid growth:
State of Kubernetes Report 2021
Kubernetes Usage:
- 28% now running in production
- 87% of organizations running containers have Kubernetes or evaluating it
- 91% success rate reported by Kubernetes adoptersLet‘s explore the two orchestrators in more depth…
Diving Into Kubernetes and OpenShift
Kubernetes and OpenShift have fundamentally similar architectures, but take different approaches in implementation.
Both orchestrate across master nodes directing worker node resources. Masters run core control plane services while workers run containerized applications and networking plugins.
However, OpenShift makes more opinionated choices around networking, storage, and cluster configuration. For example:
Architectural Approach Differences
Kubernetes:
- Bring your own networking model
- Storage agnostic - use any provider
- Operators manage own security policies
OpenShift:
- Predefined SDN model for networking
- Integrates storage classes and volumes
- Automatic security hardening These architectural decisions drive many downstream impacts…
Kubernetes offers raw infrastructure orchestration primitives. This makes it adaptable to diverse use cases but more operationally complex.
OpenShift embodies conventions and guardrails aligned to app velocity. This simplifies management but reduces flexibility for some environments.
Now, let‘s analyze key capability differences between the two container orchestrators.
Comparing Key Capabilities
While solving similar container challenges at scale, Kubernetes and OpenShift take divergent approaches across critical capability areas:
Capability Comparison
Category Kubernetes OpenShift
-----------------+----------------------+--------------------------
Open source | Yes | Uses open source but
| | commercial product
| |
Ease of use | Complex - requires | Enhanced usability
| deep skills | through abstractions
| |
Flexibility | Very flexible - | Opinionated- favors
| extend and customize | 12 Factor Apps
| |
Support options | Community | Commercial SLAs
| |
Learning curve | Steep - many custom | Lowers barriers to
| primitives to master | get started Let‘s analyze the critical differences around open source vs commercial offerings and complexity vs ease of use.
Open source Kubernetes enables custom deployments without vendor lock-in. You can adapt it to almost any infrastructure from bare metal to multiple public clouds. But you sacrifice commercial support and tested distro releases.
OpenShift incorporates open source technologies like Kubernetes and Docker. This allows Red Hat to harden security and stability while offering fixed SLAs. But your flexibility gives way to their prescriptive approach on architectural choices like networking.
Kubernetes prioritizes flexibility by offering infrastructure building blocks, not turnkey solutions. Significant operational skills become necessary to handle storage, networking, authentication, auditing and so forth.
Conversely, OpenShift directly targets ease of use through its operator-focused model. It layers in conventions around deployments, RBAC policies, data formats, CI/CD pipelines and web console UX (for both developers and admins). These guardrails certainly enable faster onboarding but limit customization opportunities.
Now that we‘ve covered the critical differences in approach, when should you consider one over the other?
When to Choose Kubernetes
Given its open-ended nature and industry momentum, Kubernetes makes sense for teams needing:
- Multi-cloud or hybrid portability
- Custom scheduling rules or cluster extensions
- Bleeding-edge features from its rapid open source innovation
- Infrastructure-focused teams with deep operational experience
Workloads where Kubernetes shines include:
- Microservices architectures
- Distributed data pipelines
- Highly complex deployments
- Custom cluster management extensions
For expert teams willing to learn, integrate and support a "toolkit" orchestrator, Kubernetes provides incredible power and flexibility.
When OpenShift Hits the Sweet Spot
Conversely, OpenShift delivers better out-of-box experience by trading off some customizability.
It works best for:
- Streamlining CI/CD pipeliness
- Empowering developers with abstraction
- Building modern 12 factor applications
- Hosting regulated workloads
You‘ll see OpenShift excel with use cases like:
- Cloud-native web and mobile applications
- Multi-tier application migration
- Teams with less Kubernetes expertise
- Environments requiring strict security policies
OpenShift simplifies what Kubernetes makes configurable – at the cost of dictating an opinionated application architecture.
Comparing Architectures In-Depth
Now that we‘ve covered the critical differences at a high-level, I want to provide more technical readers with deeper architectural comparisons between Kubernetes and OpenShift.
Both platforms offer strong high availability through replicated control plane services and worker node distribution. However each handles networking, storage and security differently.
Networking shows some of the biggest contrasts.
Kubernetes itself assumes very little about networking, offloading models to infrastructure providers, plugins like Calico, or service meshes like Istio. This means more flexibility in custom network architectures.
By contrast, OpenShift bakes in strong opinions through its Cluster Network Operator. It uses software-defined networking with defined subnets, flow rules and multitenancy separation to streamline coordination while limiting pluggability.
Storage follows similar patterns.
In Kubernetes, storage abstractions like persistent volumes allow interfacing stateful services across infrastructure targets. OpenShift centres its storage narrative around Container Native Storage along with planned quality of service tiers. This simplifies storage management for platform-aligned use cases at the potential cost of legacy system support.
Finally, security policies show deviation as well with OpenShift automating good practices like SELinux validation, user process rules and role-based access control. Kubernetes leaves more host-level security to manual operator configuration or third-party admission controllers.
Digging this deeply shows how OpenShift trades off flexibility for approachability by standardizing and enforcing consistent operational conventions.
Evaluating Migration and Transition Plans
As maturity, skill sets and needs evolve within an organization, you may need to move between Kubernetes and OpenShift. How feasible is migration between the two?
In general, moving applications from Kubernetes to OpenShift tends to be relatively smooth. Most existing Kubernetes deployments and Docker containers run without modification on OpenShift. The latter simply adds guardrails and conventions around the former.
However, the inverse poses more challenges. Migrating apps on OpenShift to stock Kubernetes requires rearchitecting around the removal of SDN policies, registry workflows and heightened permission controls. Security, networking and pipeline assumptions get displaced transitioning off those conventions back to a blank slate Kubernetes foundation.
For organizations starting greenfield or less complex application environments, Kubernetes likely makes it easier to avoid vendor lock-in. But those already invested in OpenShift ecosystem may find it less disruptive to remain through subsequent iterations.
Making Your Enterprise Decision
By this point, you should have a clearer perspective on the technical and operational differences between Kubernetes and Red Hat OpenShift. How do you ultimately decide on the right container orchestrator for your organization?
Here are the key questions to ask when evaluating Kubernetes vs OpenShift:
Application architecture – Are you deploying greenfield cloud native apps or incrementally modernizing monoliths? OpenShift favors the former while Kubernetes won‘t dictate design opinions.
Team skills – Does your staff have deep Kubernetes experience or need onboarding assistance? OpenShift smooths the initial ramp-up curve.
Infrastructure standards – Do you require hybrid cloud portability or integrate better with existing VMware, RHEL and tooling investments?
IT governance requirements – Do you handle regulated workloads or other security constraints favoring OpenShift‘s opinionated controls?
Budget parameters – Are you highly cost sensitive or willing to pay for Red Hat professional services and commercial support?
By weighing these pillars against organizational priorities, run thorough proofs of concept, and tallying votes across key stakeholders – infrastructure vs application teams – you can make determine the optimal orchestrator for your needs…at least for the next couple years until things change again!
Let the Journey Begin
I hope this guide has demystified Kubernetes vs OpenShift and provided actionable insights on evaluating between them. Container orchestration unlocks huge application velocity, operational efficiency and cloud portability benefits. Now is the time to start your deployment journey!
I welcome your feedback below. What capability stood out as most differentiating? Do you have experience or concerns to share from past selection processes? Let me know!
John @ The K8s Guy
GeekFlare Kubernetes Expert
State of Kubernetes Report 2021
Kubernetes Usage:
- 28% now running in production
- 87% of organizations running containers have Kubernetes or evaluating it
- 91% success rate reported by Kubernetes adopters
Architectural Approach Differences
Kubernetes:
- Bring your own networking model
- Storage agnostic - use any provider
- Operators manage own security policies
OpenShift:
- Predefined SDN model for networking
- Integrates storage classes and volumes
- Automatic security hardeningCapability Comparison
Category Kubernetes OpenShift
-----------------+----------------------+-------------------------
Open source | Yes | Uses open source but
| | commercial product
| |
Ease of use | Complex - requires | Enhanced usability
| deep skills | through abstractions
| |
Flexibility | Very flexible - | Opinionated- favors
| extend and customize | 12 Factor Apps
| |
Support options | Community | Commercial SLAs
| |
Learning curve | Steep - many custom | Lowers barriers to
| primitives to master | get started