example_buddy.go

package play

var _ = Buddy(&someBuddy{})

type someBuddy struct{}

func (s *someBuddy) Name() string {
	return "somebuddy"
}

func (s *someBuddy) Reconcilers() []Reconciler {
	return nil
}

example_reconciler_1.go

package play

import (
	"context"

	"sigs.k8s.io/controller-runtime/pkg/controller"
	"sigs.k8s.io/controller-runtime/pkg/manager"
	"sigs.k8s.io/controller-runtime/pkg/reconcile"
)

var _ = Reconciler(&reconciler1{})

type reconciler1 struct {
	something *somthingRunnable
}

func (r *reconciler1) SetupWithManager(context.Context, manager.Manager, controller.Options) error {
	r.something = &somthingRunnable{}
	return nil
}

func (r *reconciler1) Reconcile(context.Context, reconcile.Request) (reconcile.Result, error) {
	return reconcile.Result{}, nil
}

func (r *reconciler1) Runnables() []Runnable {
	return []Runnable{
		r.something,
	}
}

example_runnable.go

package play

import "context"

type somthingRunnable struct{}

func (s *somthingRunnable) Start(ctx context.Context) error {
	s.Download(ctx)

	// Block until done
	<-ctx.Done()

	s.Upload(context.Background())
	return nil
}

func (s *somthingRunnable) Upload(context.Context) error {
	return nil
}

func (s *somthingRunnable) Download(context.Context) error {
	return nil
}

func (s somthingRunnable) NeedLeaderElection() bool {
	return true
}

interface.go

package play

import (
	"context"

	"sigs.k8s.io/controller-runtime/pkg/controller"
	"sigs.k8s.io/controller-runtime/pkg/manager"
	"sigs.k8s.io/controller-runtime/pkg/reconcile"
)

type Buddy interface {
	Name() string

	Reconcilers() []Reconciler
}

type Reconciler interface {
	reconcile.Reconciler

	SetupWithManager(context.Context, manager.Manager, controller.Options) error
	Runnables() []Runnable
}

type Runnable interface {
	manager.LeaderElectionRunnable
	manager.Runnable
}