Introduction

The Envoy Delay Traffic attack injects a fixed delay into a configurable percentage of the traffic routed by an Envoy Gateway HTTPRoute. Use it to test how your application behaves when a route becomes slow.

How it works

The attack applies an Envoy Gateway BackendTrafficPolicy that targets the selected HTTPRoute and enables fault injection with a fixed delay:

spec:
  targetRefs:
    - group: gateway.networking.k8s.io
      kind: HTTPRoute
      name: <route>
  faultInjection:
    delay:
      fixedDelay: <delay>
      percentage: <percentage>

The policy is created when the attack starts and deleted when it stops.

Requirements

• Envoy Gateway is installed and the HTTPRoute is served by an Envoy Gateway GatewayClass.
• The Envoy Gateway discovery is enabled in the extension (discovery.disabled.envoyGateway=false).

Use Cases

• Understand how your services behave under network latency on a specific route
• Test client and downstream timeout/retry behavior
• Validate SLOs under slow-route conditions

Usage

The attack refuses to start if another BackendTrafficPolicy already targets the route (or the selected route rule). Envoy Gateway resolves conflicting policies oldest-wins, so a pre-existing policy would silently shadow the attack — remove it or target a different route/rule.

Use the optional Route Rule Name parameter to scope the fault to a single named route rule (spec.rules[].name) instead of the whole route.

Rollback

The BackendTrafficPolicy created for the attack is deleted automatically when the attack ends. If you need to clean up manually, delete the policy named steadybit-delay-<executionId> in the route's namespace (labelled steadybit.com/managed-by=extension-kubernetes).

Parameters

Parameter	Description	Default
Duration	How long the route should be affected.	30s
Traffic Percentage	The percentage of requests the delay is applied to.	50
Delay	The fixed delay injected into matching requests.	500ms
Route Rule Name	(optional) Restrict the attack to a single named route rule.