A comprehensive functional programming toolkit for Kubernetes development, providing functional wrappers for controller-runtime packages and additional utilities for composable, type-safe, and error-safe interactions with Kubernetes resources and controller patterns.
FCR brings functional programming paradigms to Kubernetes development by leveraging monadic patterns (Either, IO, Reader) from IBM/fp-go. It provides both functional wrappers for controller-runtime packages and additional utilities designed specifically for functional programming patterns, enabling:
- Composable Operations: Chain complex Kubernetes operations and controller patterns together cleanly
- Type Safety: Leverage Go's type system with functional programming patterns
- Error Safety: Handle errors explicitly through Either types
- Testability: Pure functional operations are easier to test and reason about
- Immutability: Functional approach reduces side effects and improves reliability
- Complete Ecosystem: Functional wrappers for all controller-runtime packages plus additional utilities
- 🎯 Functional Client Operations: Complete CRUD operations, status updates, and resource management with functional patterns
- 🏗️ Controller & Webhook Patterns: Type-safe controllers, managers, reconcilers, event handlers, and webhooks (Comming soon)
- 🔗 Composable Utilities: Advanced flows, transformations, query builders, retry patterns, and validation pipelines (Comming soon)
- 🛡️ Type Safety & Testing: Generic functions with compile-time checking and comprehensive test coverage
FCR provides both functional wrappers (mirroring controller-runtime packages with an f prefix) and additional utilities designed for functional programming patterns. This structure avoids naming conflicts, allowing you to import both libraries simultaneously:
import (
// controller-runtime packages
"sigs.k8s.io/controller-runtime/pkg/client"
"sigs.k8s.io/controller-runtime/pkg/controller"
"sigs.k8s.io/controller-runtime/pkg/manager"
// FCR functional wrappers
"github.com/appthrust/fcr/pkg/fclient"
"github.com/appthrust/fcr/pkg/fcontroller" // Coming soon
"github.com/appthrust/fcr/pkg/fmanager" // Coming soon
// FCR functional utilities
"github.com/appthrust/fcr/pkg/flow" // Coming soon
"github.com/appthrust/fcr/pkg/transform" // Coming soon
"github.com/appthrust/fcr/pkg/validate" // Coming soon
)| controller-runtime | FCR Wrapper | Status | Description |
|---|---|---|---|
pkg/client |
pkg/fclient |
✅ Ready | Functional client operations |
pkg/controller |
pkg/fcontroller |
🚧 Coming Soon | Functional controller patterns |
pkg/manager |
pkg/fmanager |
🚧 Coming Soon | Functional manager utilities |
pkg/builder |
pkg/fbuilder |
🚧 Coming Soon | Functional controller builders |
pkg/cache |
pkg/fcache |
🚧 Coming Soon | Functional caching operations |
pkg/handler |
pkg/fhandler |
🚧 Coming Soon | Functional event handlers |
pkg/predicate |
pkg/fpredicate |
🚧 Coming Soon | Functional predicates |
pkg/webhook |
pkg/fwebhook |
🚧 Coming Soon | Functional webhook patterns |
pkg/reconcile |
pkg/freconcile |
🚧 Coming Soon | Functional reconciler utilities |
go get github.com/appthrust/fcrFor complete API documentation, type definitions, and usage examples, visit the GoDoc reference.
We welcome contributions! Please see CONTRIBUTING.md for detailed guidelines on how to contribute to FCR.
This project is licensed under the MIT License - see the LICENSE file for details.
- Built on top of controller-runtime
- Uses IBM/fp-go for functional programming primitives
- Inspired by functional programming patterns in other languages