wip: backoff konnect strategy

internal/dataplane/sendconfig/backoff_strategy_decorator.go

@@ -0,0 +1,52 @@
+package sendconfig
+
+import (
+	"context"
+	"time"
+
+	"github.com/kong/deck/file"
+
+	"github.com/kong/kubernetes-ingress-controller/v2/internal/metrics"
+)
+
+type LastRetryProvider interface {
+	LastRetry() time.Time
+}
+
+type UpdateStrategyBackoff struct {
+	decorated         UpdateStrategy
+	lastRetryProvider LastRetryProvider
+}
+
+func NewUpdateStrategyBackoff(decorated UpdateStrategy, lastRetryProvider LastRetryProvider) UpdateStrategyBackoff {
+	return UpdateStrategyBackoff{
+		decorated:         decorated,
+		lastRetryProvider: lastRetryProvider,
+	}
+}
+
+func (s UpdateStrategyBackoff) Update(ctx context.Context, targetContent *file.Content) (
+	err error,
+	resourceErrors []ResourceError,
+	resourceErrorsParseErr error,
+) {
+	if !s.shouldUpdate() {
+		return ErrUpdateSkippedDueToBackoffStrategy, nil, nil
+	}
+
+	return s.decorated.Update(ctx, targetContent)
+}
+
+// TODO: implement this method properly
+// We can take into account the last returned error from Update() and decide whether to retry or not, e.g. if
+// - the HTTP error code was 429, we should wait the time returned in HTTP headers
+// - the config was invalid, we should retry only after the config changes
+// - ...
+func (s UpdateStrategyBackoff) shouldUpdate() bool {
+	const backoffDuration = time.Minute
+	return time.Now().After(s.lastRetryProvider.LastRetry().Add(backoffDuration))
+}
+
+func (s UpdateStrategyBackoff) MetricsProtocol() metrics.Protocol {
+	return s.decorated.MetricsProtocol()
+}

internal/dataplane/sendconfig/strategy.go

@@ -2,6 +2,7 @@ package sendconfig
 
 import (
 	"context"
+	"errors"
 
 	"github.com/kong/deck/dump"
 	"github.com/kong/deck/file"
@@ -11,6 +12,10 @@ import (
 	"github.com/kong/kubernetes-ingress-controller/v2/internal/metrics"
 )
 
+var (
+	ErrUpdateSkippedDueToBackoffStrategy = errors.New("update skipped due to backoff strategy")
+)
+
 // UpdateStrategy is the way we approach updating data-plane's configuration, depending on its type.
 type UpdateStrategy interface {
 	// Update applies targetConfig to the data-plane.
@@ -63,14 +68,18 @@ func (r DefaultUpdateStrategyResolver) ResolveUpdateStrategy(
 	// In case the client communicates with Konnect Admin API, we know it has to use DB-mode. There's no need to check
 	// config.InMemory that is meant for regular Kong Gateway clients.
 	if client.IsKonnect() {
-		return NewUpdateStrategyDBMode(
-			adminAPIClient,
-			dump.Config{
-				SkipCACerts:         true,
-				KonnectRuntimeGroup: client.KonnectRuntimeGroup(),
-			},
-			r.config.Version,
-			r.config.Concurrency,
+		return NewUpdateStrategyBackoff(
+			NewUpdateStrategyDBMode(
+				adminAPIClient,
+				dump.Config{
+					SkipCACerts:         true,
+					KonnectRuntimeGroup: client.KonnectRuntimeGroup(),
+				},
+				r.config.Version,
+				r.config.Concurrency,
+			),
+			// TODO: pass a proper LastRetryProvider here that keeps track of the last retry time between ResolveUpdateStrategy calls.
+			nil,
 		)
 	}