Working with Generators

Working with Generators

Generators provide a type-safe way to create application workloads from configuration. They implement the ApplicationConfig interface and are identified by GroupVersionKind (GVK) strings.

Getting Started

The fastest way to start a new project is with kure init:

kure init my-cluster

This creates a ready-to-use directory structure with cluster.yaml and an example application under apps/. You can then generate manifests with:

kure generate cluster cluster.yaml

See kure init --help for options like --gitops argocd.

The GVK System

Each generator is registered with a GVK identifier that uniquely identifies its type:

Using Generators

From Code

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

// Look up generator by GVK
factory, err := generators.GetGenerator("generators/AppWorkload")

// Create config from YAML data
config, err := factory.FromConfig(yamlData)

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

From YAML Configuration

Generators can be configured via YAML files:

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

Listing Available Generators

// List all registered generator GVKs
gvks := generators.ListRegistered()

Built-in Generators

AppWorkload

Generates a complete application deployment:

• Deployment with configurable replicas, image, resource limits
• Service with port mappings
• Optional ConfigMap for configuration data
• Optional ServiceAccount

FluxHelm

Generates Flux HelmRelease resources:

• HelmRelease with chart reference and values
• HelmRepository source (when needed)
• ChartRef support for OCI-based charts (alternative to HelmRepository)
• Configurable remediation strategies (install/upgrade retries, rollback)
• ValuesFrom references for external value sources
• PostRenderer Kustomize patches for chart output customization
• Target namespace and release name overrides

KurelPackage

Generates Kubernetes resource objects from kurel packages. Generate() delegates to GeneratePackageFiles(), extracts the resource files from the package, and parses them into typed objects. Non-resource metadata (kurel.yaml, patches, values, extensions) is excluded from the output. This allows kurel packages to participate in the stack generation pipeline alongside code-generated resources.

Custom Generators

Register your own generators:

generators.Register("mycompany/CustomApp", &MyGeneratorFactory{})

The factory must implement the generator interface, providing a FromConfig method that returns an ApplicationConfig.

Further Reading

• Generators reference for API details
• Generator examples for working samples
• Flux workflow for using generators in clusters