OpenShift vs. OpenStack

OpenShift and OpenStack are used to build scalable cloud platforms. When combined, the systems cover the entire range – from pro­vi­sion­ing vir­tu­al­ized hardware to de­vel­op­ing and operating con­tainer­ized ap­pli­ca­tions. OpenShift and OpenStack are popular with large, global or­ga­ni­za­tions 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 vir­tu­al­iza­tion has become the dominant vir­tu­al­iza­tion 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 or­ga­ni­za­tions 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 con­tainer­ized ap­pli­ca­tions. Users can provide, operate, and monitor ap­pli­ca­tions and services them­selves, and focus on optimized de­vel­op­ment and DevOps workflows.

OpenStack, on the other hand, comes with a deeper level of ab­strac­tion. The platform is used to build a vir­tu­al­ized 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, or­ga­ni­za­tions 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 cen­tral­ized 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 de­cen­tral­ized 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 or­ga­ni­za­tions 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 de­cen­tral­ized 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 vir­tu­al­iza­tion 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 cen­tral­ized policy man­age­ment. This ensures a high-quality standard across the software landscape of an entire or­ga­ni­za­tion. 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 au­tho­riza­tion 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 toward large or­ga­ni­za­tions and is too complex for in­di­vid­ual de­vel­op­ers to deal with.