Implement graceful shutdown. (#26)

* Disable timeout to guarantee deletion flow succeeds before stop.

* Fix.

controllers/duros_controller.go

@@ -98,13 +98,17 @@ func (r *DurosReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl
 		}
 	} else {
 		// object is being deleted
+		// we don't pass the cancelled context here because then our deletion
+		// procedure will stop prematurely
+		deletionCtx := context.Background()
+
 		if containsString(duros.GetFinalizers(), DurosFinalizerName) {
-			if err := r.cleanupResources(ctx); err != nil {
+			if err := r.cleanupResources(deletionCtx); err != nil {
 				return requeue, err
 			}
 
 			controllerutil.RemoveFinalizer(duros, DurosFinalizerName)
-			if err := r.Update(ctx, duros); err != nil {
+			if err := r.Update(deletionCtx, duros); err != nil {
 				return requeue, err
 			}
 		}

main.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"flag"
 	"os"
+	"time"
 
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
@@ -111,13 +112,15 @@ func main() {
 
 	restConfig := ctrl.GetConfigOrDie()
 
+	disabledTimeout := time.Duration(-1) // wait for all runnables to finish before dying
 	mgr, err := ctrl.NewManager(restConfig, ctrl.Options{
-		Scheme:             scheme,
-		MetricsBindAddress: metricsAddr,
-		Port:               9443,
-		LeaderElection:     enableLeaderElection,
-		LeaderElectionID:   "duros-controller-leader-election",
-		Namespace:          namespace,
+		Scheme:                  scheme,
+		MetricsBindAddress:      metricsAddr,
+		Port:                    9443,
+		LeaderElection:          enableLeaderElection,
+		LeaderElectionID:        "duros-controller-leader-election",
+		Namespace:               namespace,
+		GracefulShutdownTimeout: &disabledTimeout,
 	})
 	if err != nil {
 		setupLog.Error(err, "unable to start duros-controller")