Add jitter to poll interval

cmd/provider/main.go

@@ -54,6 +54,7 @@ func main() {
 		debug                    = app.Flag("debug", "Run with debug logging.").Short('d').Bool()
 		syncInterval             = app.Flag("sync", "Controller manager sync period such as 300ms, 1.5h, or 2h45m").Short('s').Default("1h").Duration()
 		pollInterval             = app.Flag("poll", "Poll interval controls how often an individual resource should be checked for drift.").Default("1m").Duration()
+		pollJitterPercentage     = app.Flag("poll-jitter-percentage", "Percentage of jitter to apply to poll interval. It cannot be negative, and must be less than 100.").Default("10").Uint()
 		leaderElection           = app.Flag("leader-election", "Use leader election for the controller manager.").Short('l').Default("false").Envar("LEADER_ELECTION").Bool()
 		maxReconcileRate         = app.Flag("max-reconcile-rate", "The number of concurrent reconciliations that may be running at one time.").Default("10").Int()
 		enableManagementPolicies = app.Flag("enable-management-policies", "Enable support for Management Policies.").Default("true").Envar("ENABLE_MANAGEMENT_POLICIES").Bool()
@@ -72,6 +73,16 @@ func main() {
 		ctrl.SetLogger(zl)
 	}
 
+	if *pollJitterPercentage >= 100 {
+		kingpin.Fatalf("invalid --poll-jitter-percentage %v must be less than 100", *pollJitterPercentage)
+	}
+	pollJitter := time.Duration(float64(*pollInterval) * (float64(*pollJitterPercentage) / 100.0))
+	log.Debug("Starting",
+		"sync-interval", syncInterval.String(),
+		"poll-interval", pollInterval.String(),
+		"poll-jitter", pollJitter.String(),
+		"max-reconcile-rate", *maxReconcileRate)
+
 	cfg, err := ctrl.GetConfig()
 	kingpin.FatalIfError(err, "Cannot get API server rest config")
 
@@ -130,7 +141,7 @@ func main() {
 	// notice and remove when we drop support for v1alpha1.
 	kingpin.FatalIfError(ctrl.NewWebhookManagedBy(mgr).For(&v1alpha1.Object{}).Complete(), "Cannot create Object webhook")
 
-	kingpin.FatalIfError(object.Setup(mgr, o, *sanitizeSecrets), "Cannot setup controller")
+	kingpin.FatalIfError(object.Setup(mgr, o, *sanitizeSecrets, pollJitter), "Cannot setup controller")
 	kingpin.FatalIfError(mgr.Start(ctrl.SetupSignalHandler()), "Cannot start controller manager")
 }
 

internal/controller/kubernetes.go

@@ -17,6 +17,8 @@ limitations under the License.
 package controller
 
 import (
+	"time"
+
 	ctrl "sigs.k8s.io/controller-runtime"
 
 	"github.com/crossplane/crossplane-runtime/pkg/controller"
@@ -27,11 +29,11 @@ import (
 
 // Setup creates all Template controllers with the supplied logger and adds them to
 // the supplied manager.
-func Setup(mgr ctrl.Manager, o controller.Options, sanitizeSecrets bool) error {
+func Setup(mgr ctrl.Manager, o controller.Options, sanitizeSecrets bool, pollJitter time.Duration) error {
 	if err := config.Setup(mgr, o); err != nil {
 		return err
 	}
-	if err := object.Setup(mgr, o, sanitizeSecrets); err != nil {
+	if err := object.Setup(mgr, o, sanitizeSecrets, pollJitter); err != nil {
 		return err
 	}
 	return nil

internal/controller/object/object.go

@@ -21,6 +21,7 @@ import (
 	"encoding/base64"
 	"fmt"
 	"strings"
+	"time"
 
 	"github.com/pkg/errors"
 	v1 "k8s.io/api/core/v1"
@@ -91,7 +92,7 @@ const (
 )
 
 // Setup adds a controller that reconciles Object managed resources.
-func Setup(mgr ctrl.Manager, o controller.Options, sanitizeSecrets bool) error {
+func Setup(mgr ctrl.Manager, o controller.Options, sanitizeSecrets bool, pollJitter time.Duration) error {
 	name := managed.ControllerName(v1alpha2.ObjectGroupKind)
 
 	cps := []managed.ConnectionPublisher{managed.NewAPISecretPublisher(mgr.GetClient(), mgr.GetScheme())}
@@ -112,6 +113,7 @@ func Setup(mgr ctrl.Manager, o controller.Options, sanitizeSecrets bool) error {
 		}),
 		managed.WithFinalizer(&objFinalizer{client: mgr.GetClient()}),
 		managed.WithPollInterval(o.PollInterval),
+		managed.WithPollJitterHook(pollJitter),
 		managed.WithLogger(o.Logger.WithValues("controller", name)),
 		managed.WithRecorder(event.NewAPIRecorder(mgr.GetEventRecorderFor(name))),
 		managed.WithConnectionPublishers(cps...),