Generators

Generators - Application Generator System

The generators package provides a type-safe system for creating Kubernetes application workloads from configuration. Generators implement the stack.ApplicationConfig interface, allowing them to be used as applications within the domain model.

Overview

Generators use the GroupVersionKind (GVK) type system to identify and instantiate application configurations. Each generator is registered in the stack package’s global registry and can be referenced by its GVK identifier.

Available Generators

Generator	GVK	Description
AppWorkload	`generators/AppWorkload`	General-purpose application workload with Deployment, Service, ConfigMap
FluxHelm	`generators/FluxHelm`	HelmRelease-based application using Flux
KurelPackage	`generators/KurelPackage`	Kurel package reference for pre-built application packages

Usage

Creating a Generator from GVK

import "github.com/go-kure/kure/pkg/stack"

// Create application config by apiVersion and kind
config, err := stack.CreateApplicationConfig("generators.gokure.dev/v1alpha1", "AppWorkload")

// Use in domain model
app := stack.NewApplication("my-app", "default", config)

YAML Configuration Format

Generators are typically configured via YAML:

apiVersion: generators/v1
kind: AppWorkload
metadata:
  name: my-web-app
spec:
  image: nginx:1.25
  replicas: 3
  ports:
    - containerPort: 80
      servicePort: 80
  env:
    - name: LOG_LEVEL
      value: info

Registry

stack.RegisterApplicationConfig(gvk.GVK{
    Group:   "mycompany.dev",
    Version: "v1",
    Kind:    "CustomApp",
}, func() stack.ApplicationConfig {
    return &MyCustomConfig{}
})

Query available generators:

// List all registered generator GVKs
gvks := stack.ListApplicationConfigGVKs()

Sub-packages

appworkload

General-purpose application generator that produces:

Deployment with configurable replicas, image, resources
Service with port mappings
Optional ConfigMap for configuration data
Optional ServiceAccount

fluxhelm

Generates Flux HelmRelease resources for Helm-based applications:

HelmRelease with chart reference
HelmRepository source (if needed)
Values configuration

kurelpackage

Generates Kubernetes resource objects from kurel packages. The Generate() method delegates to GeneratePackageFiles(), extracts files under the resources/ prefix, and parses each one into typed client.Object values. Non-resource files (kurel.yaml, patches, values, extensions) are excluded — they are package metadata. This makes KurelPackage configs usable in the stack generation pipeline alongside other generators.

stack - Core domain model and ApplicationConfig interface
stack/fluxcd - Flux workflow engine