[operator] Use contexts instead of channels for Run methods

examples/operator/opinionated/reconciler/main.go

@@ -7,7 +7,6 @@ import (
 	"log"
 	"os"
 	"os/signal"
-	"syscall"
 	"time"
 
 	"github.com/grafana/grafana-app-sdk/k8s"
@@ -125,21 +124,14 @@ func main() {
 	// Informers also implement Controller, so we can use them as a controller directly if there's no need for an intermediary.
 	op.AddController(informerController)
 
-	// Create the stop channel
-	stopCh := make(chan struct{}, 1)
-
-	// Set up a signal handler
-	sigChan := make(chan os.Signal, 1)
-	signal.Notify(sigChan, syscall.SIGHUP, syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT)
-	go func() {
-		<-sigChan
-		close(stopCh)
-	}()
+	// Create the run context
+	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt, os.Kill)
+	defer cancel()
 
 	log.Printf("%sStarting Operator%s", green, nc)
 
 	// Run the controller (will block until stopCh receives a message or is closed)
-	err = op.Run(stopCh)
+	err = op.Run(ctx)
 	if err != nil {
 		panic(fmt.Errorf("error running operator: %w", err))
 	}

examples/operator/opinionated/watcher/main.go

@@ -7,7 +7,6 @@ import (
 	"log"
 	"os"
 	"os/signal"
-	"syscall"
 	"time"
 
 	"github.com/grafana/grafana-app-sdk/k8s"
@@ -120,21 +119,14 @@ func main() {
 	// Informers also implement Controller, so we can use them as a controller directly if there's no need for an intermediary.
 	op.AddController(informer)
 
-	// Create the stop channel
-	stopCh := make(chan struct{}, 1)
-
 	// Set up a signal handler
-	sigChan := make(chan os.Signal, 1)
-	signal.Notify(sigChan, syscall.SIGHUP, syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT)
-	go func() {
-		<-sigChan
-		close(stopCh)
-	}()
+	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt, os.Kill)
+	defer cancel()
 
 	log.Printf("%sStarting Operator%s", green, nc)
 
 	// Run the controller (will block until stopCh receives a message or is closed)
-	op.Run(stopCh)
+	op.Run(ctx)
 }
 
 type OpinionatedModel struct {

examples/operator/simple/reconciler/main.go

@@ -7,7 +7,6 @@ import (
 	"log"
 	"os"
 	"os/signal"
-	"syscall"
 	"time"
 
 	"github.com/grafana/grafana-app-sdk/k8s"
@@ -89,21 +88,14 @@ func main() {
 		panic(fmt.Errorf("unable to reconcile kind: %w", err))
 	}
 
-	// Create the stop channel
-	stopCh := make(chan struct{}, 1)
-
 	// Set up a signal handler
-	sigChan := make(chan os.Signal, 1)
-	signal.Notify(sigChan, syscall.SIGHUP, syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT)
-	go func() {
-		<-sigChan
-		close(stopCh)
-	}()
+	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt, os.Kill)
+	defer cancel()
 
 	log.Print("\u001B[1;32mStarting Operator\u001B[0m")
 
 	// Run the controller (will block until stopCh receives a message or is closed)
-	err = simpleOperator.Run(stopCh)
+	err = simpleOperator.Run(ctx)
 	if err != nil {
 		panic(fmt.Errorf("error running operator: %w", err))
 	}

examples/operator/simple/watcher/main.go

@@ -7,7 +7,6 @@ import (
 	"log"
 	"os"
 	"os/signal"
-	"syscall"
 	"time"
 
 	"github.com/grafana/grafana-app-sdk/k8s"
@@ -96,21 +95,14 @@ func main() {
 		panic(fmt.Errorf("unable to watch kind: %w", err))
 	}
 
-	// Create the stop channel
-	stopCh := make(chan struct{}, 1)
-
 	// Set up a signal handler
-	sigChan := make(chan os.Signal, 1)
-	signal.Notify(sigChan, syscall.SIGHUP, syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT)
-	go func() {
-		<-sigChan
-		close(stopCh)
-	}()
+	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt, os.Kill)
+	defer cancel()
 
 	log.Print("\u001B[1;32mStarting Operator\u001B[0m")
 
 	// Run the controller (will block until stopCh receives a message or is closed)
-	err = simpleOperator.Run(stopCh)
+	err = simpleOperator.Run(ctx)
 	if err != nil {
 		panic(fmt.Errorf("error running operator: %w", err))
 	}

operator/informer_controller.go

@@ -9,11 +9,14 @@ import (
 
 	"github.com/prometheus/client_golang/prometheus"
 
+	"github.com/grafana/grafana-app-sdk/app"
 	"github.com/grafana/grafana-app-sdk/logging"
 	"github.com/grafana/grafana-app-sdk/metrics"
 	"github.com/grafana/grafana-app-sdk/resource"
 )
 
+var _ Controller = &InformerController{}
+
 type ResourceAction string
 
 const (
@@ -38,8 +41,8 @@ var DefaultErrorHandler = func(ctx context.Context, err error) {
 
 // Informer is an interface describing an informer which can be managed by InformerController
 type Informer interface {
+	app.Runnable
 	AddEventHandler(handler ResourceWatcher) error
-	Run(stopCh <-chan struct{}) error
 }
 
 // ResourceWatcher describes an object which handles Add/Update/Delete actions for a resource
@@ -283,14 +286,16 @@ func (c *InformerController) RemoveAllReconcilersForResource(resourceKind string
 // Run runs the controller, which starts all informers, until stopCh is closed
 //
 //nolint:errcheck
-func (c *InformerController) Run(stopCh <-chan struct{}) error {
+func (c *InformerController) Run(ctx context.Context) error {
+	derivedCtx, cancel := context.WithCancel(ctx)
+	defer cancel()
 	c.informers.RangeAll(func(_ string, _ int, inf Informer) {
-		go inf.Run(stopCh)
+		go inf.Run(derivedCtx)
 	})
 
-	go c.retryTicker(stopCh)
+	go c.retryTicker(derivedCtx)
 
-	<-stopCh
+	<-ctx.Done()
 
 	return nil
 }
@@ -542,7 +547,7 @@ func (c *InformerController) doReconcile(ctx context.Context, reconciler Reconci
 // retryTicker blocks until stopCh is closed or receives a message.
 // It checks if there are function calls to be retried every second, and, if there are any, calls the function.
 // If the function returns an error, it schedules a new retry according to the RetryPolicy.
-func (c *InformerController) retryTicker(stopCh <-chan struct{}) {
+func (c *InformerController) retryTicker(ctx context.Context) {
 	ticker := time.NewTicker(c.retryTickerInterval)
 	defer ticker.Stop()
 	for {
@@ -583,7 +588,7 @@ func (c *InformerController) retryTicker(stopCh <-chan struct{}) {
 					c.toRetry.AddItem(key, inf)
 				}
 			}
-		case <-stopCh:
+		case <-ctx.Done():
 			return
 		}
 	}