Pattern-Based Application Development in k8or Orbit
By Anna V. May 28, 2024. Revised. Version: 0.1.03
Definition & Purpose k8or Orbit Patterns are predefined, opinionated models for structuring both application design and cluster-level infrastructure. By adhering to these patterns, developers can either build new applications or adapt existing ones to fit proven, standardized approaches—ensuring consistent deployments, streamlined operations, and simplified maintenance across the k8or ecosystem.
Key Principles
Standardized Building Blocks
Each pattern prescribes fundamental components (e.g., service mesh, Dapr sidecars, telemetry, curated SQL/NoSQL databases) and how they interconnect in a K3s cluster.
App-Level & Infra-Level
Application Patterns define how microservices, messaging, or stateful resources fit together.
Infrastructure Patterns govern cluster bootstrapping, security policies, logging/monitoring frameworks, and general best practices for environment setup.
Ease of Adoption
Instead of developers “reinventing the wheel,” they map their use case to a relevant pattern (e.g., a web app with standard config, a real-time streaming pattern, or a multi-tier data pipeline).
Patterns provide sample architectures, Helm charts, or standard CRDs, reducing guesswork.
Flexibility vs. Consistency
Patterns don’t lock you into a single rigid blueprint; they offer a guided approach with recommended best practices.
You can extend or override parts to address unique needs, but the core remains consistent.
Non-Pattern vs. Pattern
In a non-pattern approach, each developer might assemble AWS or Kubernetes components differently, leading to inconsistency.
In a pattern-based approach, the same fundamental architecture is reused, simplifying collaboration, scaling, and maintenance.
Outcome
By adopting k8or Orbit Patterns, teams can accelerate development, reduce operational complexity, and ensure that each new or migrated application leverages proven design principles—thereby aligning every deployment with the broader k8or Orbit ecosystem’s best practices.
2. What Are Patterns in k8or Orbit?
Patterns in k8or Orbit are pre-defined templates and best practices that outline how various parts of an application—and even the underlying infrastructure—should be constructed and interconnected. They exist at multiple levels:
Application-Level Patterns: Define how microservices interact, specify data flows, and determine the standard methods for securing communication. For example, an application pattern might detail how a web app should connect its front end (FE), middleware (MW), and backend (BE) using prescribed interfaces and consistent naming conventions.
Infrastructure-Level Patterns (Cluster Bootstrapping): Define how the base Kubernetes cluster is set up using standardized components. This includes the pre-provisioning of core resources like service meshes, networking policies, persistent storage configurations, and security policies.
By providing a clear set of building blocks, k8or Orbit enables the creation of predictable, repeatable, and maintainable deployments across diverse environments.
3. Benefits of Adopting a Pattern-Based Approach
Consistency and Standardization:
Uniformity: Every developer can build applications in the same way, reducing variability and error.
Predictable Deployments: Standardized components simplify troubleshooting and support.
Efficiency in Development:
Faster Time-to-Market: Pre-defined templates allow developers to focus on business logic rather than infrastructure details.
Simplified Integration: With well-defined interfaces (e.g., FE-to-MW, MW-to-BE), integration between components is more straightforward.
Scalability and Maintainability:
Easier Upgrades and Refactoring: Centralized patterns can be updated, and changes propagate consistently through all applications built on these patterns.
Reduced Technical Debt: By following a proven methodology, teams avoid ad hoc solutions that complicate future enhancements.
Improved Collaboration and Knowledge Sharing:
Shared Best Practices: Patterns serve as a common language for developers, simplifying cross-team collaboration.
Lower Onboarding Time: New team members can quickly learn the standard patterns rather than deciphering diverse legacy approaches.
4. How k8or Orbit Implements Pattern-Based Development
4.1 Developer Workflow Options
Creating New Applications: Developers can choose from a library of pre-defined patterns (or blueprints) when starting a new project. These patterns include all the necessary configurations to deploy the application on a k3s cluster using the k8or Orbit framework.
Porting Existing Applications: For existing applications built in a non-patterned way, tools and guidelines are provided to “convert” them into a standardized format. This might involve reconfiguring service endpoints, adopting standard naming/numbering conventions, and packaging components into modular Helm charts or Kustomize overlays.
4.2 Standardized Deployment Components
Helm Charts & Umbrella Charts: Each application pattern is backed by modular Helm charts for individual components (such as FE, MW, BE). An umbrella chart can then integrate these into a single deployable unit, ensuring that inter-component interfaces are correctly configured.
Cluster Bootstrapping Scripts: For infrastructure-level patterns, standardized bootstrap scripts automatically provision namespaces, RBAC policies, network configurations, and persistent volume setups. These scripts guarantee that every new cluster starts with a known, consistent configuration.
Service Mesh and Telemetry: Patterns include integration points for service meshes (like Istio) and telemetry solutions (such as Prometheus and Grafana) to provide advanced routing, security, and monitoring with minimal configuration by developers.
5. A Real-World Example: The Food-App Pattern
Imagine the Food-App, a three-tier application with:
A Front End (FE MSV) built in Angular.
A Middleware (MW MSV) implemented in PHP.
A Back End (BE RES) with a containerized MySQL database and PVCs.
Using a pattern-based approach:
Standard Interfaces: The FE MSV is expected to call the MW MSV via a defined API endpoint, and the MW MSV connects to the BE RES with a standard connection string.
Pre-Configured Helm Charts: Separate Helm charts are available for each tier and bundled under an umbrella chart that includes consistent, organization-defined values.
Cluster Bootstrapping: Pre-deployment scripts automatically set up necessary namespaces, RBAC policies, persistent volumes, and networking rules.
GitOps Integration: Argo CD continuously monitors the Git repository for changes and synchronizes deployments, ensuring that the Food-App adheres strictly to the pattern.
This approach ensures that regardless of the developer’s individual practices, the Food-App is built and deployed in a standardized manner, making maintenance and scaling predictable and efficient.
6. Takeway
Pattern-based application development in k8or Orbit transforms how applications are built and deployed by establishing a set of standardized, modular templates for both the application and its underlying infrastructure. Whether you’re starting a new project or converting existing applications, these patterns help you achieve consistency, efficiency, scalability, and easier collaboration. By leveraging a common blueprint for inter-service communication and infrastructure provisioning—through tools like Helm, CI/CD pipelines, and GitOps operators—developers can deliver robust, predictable, and maintainable applications on k3s clusters with reduced complexity and technical debt.
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