Top Design Patterns for the Modern Hybrid Cloud with OpenShift: Part 1

Introduction #

Welcome back to MeatyBytes.io, I’m your host, Nick Miethe. As you probably already know, I’m an avid hobbyist, tech enthusiast, and a seasoned OpenShift devotee. My fascination with cloud technologies and OpenShift isn’t just a professional interest, it’s a passion of mine. I’ve seen firsthand how these technologies are redefining the way we approach software development and deployment. So today, we’re going to journey into the ever-evolving landscape of the Hybrid Cloud and explore some of the patterns I’ve seen and developed across numerous organizations of all sizes.

Magical World of Hybrid Cloud #

In the evolving landscape of cloud technologies, it is crucial to understand and implement effective design patterns. These patterns can simplify the deployment and scaling of applications, especially in a hybrid cloud environment using OpenShift. However, as technologies evolve, so do the applicable design patterns. They adapt, transform, disappear, or remain relevant based on the current state of technology and specific requirements of the system at hand. As we explore these design patterns, we’ll also take a look at how OpenShift facilitates these paradigms, making the implementation process seamless and more manageable. Whether you’re an experienced cloud architect or a developer venturing into hybrid cloud solutions, this post promises to be a treasure trove of insights.

In this 2 part series, we will explore the top 10 design patterns for the modern hybrid cloud with OpenShift, analyzing their development, necessity, and applications. These patterns have roots in the traditional Kubernetes design patterns but have evolved to address specific challenges and needs of the modern hybrid cloud environment.

In this post, we will deep-dive into some of the top design patterns for developing and deploying applications in a modern hybrid cloud environment using OpenShift. From leveraging microservices to implementing serverless architectures, these patterns aren’t just about cutting-edge tech, they’re about creating scalable, resilient, and manageable applications in the cloud.

But before we delve into the new patterns, let’s take a brief look at the foundational ideas and some classic Kubernetes patterns.

The Gang of Four and Kubernetes Design Patterns #

Design patterns were popularized in the software engineering world by the Gang of Four (GoF), consisting of Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides. They published a book in 1994 titled Design Patterns: Elements of Reusable Object-Oriented Software, which laid the foundation for using patterns to solve recurring design problems and improve the flexibility and reusability of software.

In the realm of Kubernetes, these patterns have been adapted to the specific needs of deploying and scaling containerized applications. Some of the key patterns from the Kubernetes world include:

• The Single-Container Pattern, where one application is deployed inside a container, ensuring the container holds just one responsibility.
• The Sidecar Pattern extends the behavior of a container by attaching a sidecar container that offers supporting features to the main application.
• The Ambassador Pattern is useful for running additional services with the main container and simplifies the main container’s access to other services.
• The Adapter Pattern maintains consistency in communication between containers and can transform the primary container’s output to fit application standards.
• The Leader Election Pattern is useful when we need to replicate running components and elect a leader from a set of running replicas.
• The Work Queue Pattern focuses on splitting up a large task into smaller tasks to reduce running time.
• The Scatter/Gather Pattern also splits a large task into smaller ones but with a focus on responding to the user.
• The Init Container Pattern includes a configuration related to the task for which the container is made, often replacing the default configuration with custom ones during deployment.

While these patterns are highly useful in a Kubernetes context, the move to a hybrid cloud environment necessitates the evolution of some patterns and the development of new ones. Let’s explore some of these patterns specifically tailored for a modern hybrid cloud with OpenShift.

1. The Federated Identity Pattern #

The Federated Identity Pattern is a modern cloud design pattern that has grown in importance with the rise of hybrid cloud environments. It addresses the challenge of managing user identities and access across multiple systems that may be spread across different cloud platforms and on-premises environments.

The Federated Identity Pattern leverages identity federation technology to enable users to use the same identity (i.e., username and password or digital identity) across all systems in the hybrid cloud. This significantly simplifies user management and enhances security as there is a single source of truth for user identities.

In a hybrid OpenShift environment, for example, you might have clusters running in different public clouds and on-premises. Each of these clusters may have its own authentication system, which can be challenging to manage. By implementing the Federated Identity Pattern, you can use a unified identity provider, such as AD or Keycloak, to manage user access across all your OpenShift clusters.

Example: A user who has access to multiple OpenShift clusters can use the same credentials to log into all of them, simplifying the user experience and reducing the administrative overhead of managing separate user identities for each cluster.

2. The Service Mesh Pattern #

The Service Mesh Pattern is a design pattern that has gained popularity with the rise of microservices. It provides a way to manage how different parts of an application share data with each other. This is especially useful in a hybrid cloud environment where services may be distributed across multiple platforms and locations, as well as multi-tenant platforms where a single environment might hold multiple customers’ data.

In OpenShift, a service mesh can be implemented using tools like Istio/OpenShift Service Mesh. These tools provide features like traffic control, service discovery, load balancing, and security for microservices communication.

Example: An OpenShift application composed of multiple microservices running on different cloud platforms can use a service mesh to handle service-to-service communication, ensuring consistent performance and robust security.

3. The Multi-Cluster Management Pattern #

As the name suggests, the Multi-Cluster Management Pattern is all about managing multiple Kubernetes clusters across a hybrid cloud environment. This pattern has become increasingly necessary as organizations deploy workloads across multiple clouds and on-premises environments for reasons like cost efficiency, regulatory compliance, and high availability.

OpenShift provides several tools for multi-cluster management, including Red Hat Advanced Cluster Management for Kubernetes (RHACM). This tool provides features like cluster lifecycle management, application lifecycle management, policy-based governance, and disaster recovery.

Example: An organization can manage its OpenShift clusters deployed across multiple public clouds and on-premises data centers from a single control plane, simplifying operations and reducing the risk of misconfigurations.

4. The GitOps Pattern #

The GitOps pattern is a modern approach to continuous delivery (the CD in CI/CD) in cloud-native environments. It leverages Git as the single source of truth for both infrastructure and application code. This pattern makes it easy to track changes, roll back when necessary, and maintain consistency across different environments.

In OpenShift, you can implement GitOps using tools like ArgoCD/OpenShift GitOps, which integrate seamlessly with Git repositories. Changes to the Git repository trigger automated pipelines that deploy those changes to the appropriate environments.

Example: A development team can manage and version their OpenShift application code and configuration in a Git repository. Any changes to the repository automatically trigger a pipeline that deploys those changes to the relevant OpenShift clusters, ensuring consistency and reliability.

5. The Serverless Pattern #

The Serverless Pattern is a design pattern that allows developers to focus on writing code without worrying about the underlying infrastructure. It’s a way to deploy applications in a flexible and scalable way without the need to manage servers.

In OpenShift, you can implement the Serverless Pattern using Knative/OpenShift Serverless, a Kubernetes-based platform to build, deploy, and manage modern serverless workloads. It provides features like scaling to zero when no instances of the application are running, automatic scaling based on demand, and event-driven architecture support.

Example: An OpenShift application can leverage Knative to automatically scale based on demand, reducing resource usage during periods of low traffic and quickly scaling up when demand increases.

Conclusion #

Design patterns play a crucial role in helping developers and architects design and implement efficient, scalable, and resilient systems. While the classic Kubernetes patterns still hold significant value, the evolution to hybrid cloud environments necessitates the emergence and adaptation of new patterns.

In this post, we explored five such patterns specifically tailored for the modern hybrid cloud with OpenShift: the Federated Identity Pattern, the Service Mesh Pattern, the Multi-Cluster Management Pattern, the GitOps Pattern, and the Serverless Pattern. These patterns address the unique challenges of deploying and managing applications in a hybrid cloud environment, helping organizations to deliver more reliable and efficient services. In my next post, we’ll explore 5 more patterns to help create that one-stop-shop for all your Platform needs.

As the landscape of cloud technologies continues to evolve, it is essential for developers and architects to stay updated on emerging patterns and trends. This way, they can make the most of the opportunities offered by these advancements while mitigating the challenges they may bring.

Stay tuned!

References #

• Top 10 Design Patterns for Kubernetes
• Design Patterns: Elements of Reusable Object-Oriented Software
• Kubernetes Patterns
• Red Hat architecture and design patterns | Red Hat Developer