Delivery Format: set kn-ingress-format ce extension on mt channel based broker ingress

[Cali0707]

Problem
To support dispatching events from the MTChannelBasedBroker with the correct format when a user sets the spec.delivery.format to ingress, we need to set a cloudevent extension of kn-ingress-format to specify which format was used. This should be set to structured if the input event was structured, and binary if the input event was in binary. However, since this event may have been forwarded from earlier ingress, we need to only set the kn-ingress-format extension if it is not already present on the event.

Persona:
Which persona is this feature for?

Exit Criteria
Unit tests verifying that:

1. If the extension is not present it is set correctly for both structured and binary events
2. If the extension is already present, it is not changed for both structured and binary events

Time Estimate (optional):
How many developer-days do you think this may take to resolve? 1-2

Additional context (optional)
Add any other context about the feature request here.

• The parent issue is: Delivery Format: support specifying the event format #8057
• The broker ingress handler code is here:

  eventing/pkg/broker/ingress/ingress_handler.go

  Lines 172 to 283 in 5f6713a

  	func (h *Handler) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
  	writer.Header().Set("Allow", "POST, OPTIONS")
  	// validate request method
  	if request.Method == http.MethodOptions {
  	writer.Header().Set("WebHook-Allowed-Origin", "*") // Accept from any Origin:
  	writer.Header().Set("WebHook-Allowed-Rate", "*") // Unlimited requests/minute
  	writer.WriteHeader(http.StatusOK)
  	return
  	}
  	if request.Method != http.MethodPost {
  	h.Logger.Warn("unexpected request method", zap.String("method", request.Method))
  	writer.WriteHeader(http.StatusMethodNotAllowed)
  	return
  	}
  	// validate request URI
  	if request.RequestURI == "/" {
  	writer.WriteHeader(http.StatusNotFound)
  	return
  	}
  	nsBrokerName := strings.Split(strings.TrimSuffix(request.RequestURI, "/"), "/")
  	if len(nsBrokerName) != 3 {
  	h.Logger.Info("Malformed uri", zap.String("URI", request.RequestURI))
  	writer.WriteHeader(http.StatusBadRequest)
  	return
  	}
  	ctx := h.withContext(request.Context())
  	message := cehttp.NewMessageFromHttpRequest(request)
  	defer message.Finish(nil)
  	event, err := binding.ToEvent(ctx, message)
  	if err != nil {
  	h.Logger.Warn("failed to extract event from request", zap.Error(err))
  	writer.WriteHeader(http.StatusBadRequest)
  	return
  	}
  	// run validation for the extracted event
  	validationErr := event.Validate()
  	if validationErr != nil {
  	h.Logger.Warn("failed to validate extracted event", zap.Error(validationErr))
  	writer.WriteHeader(http.StatusBadRequest)
  	return
  	}
  	brokerNamespace := nsBrokerName[1]
  	brokerName := nsBrokerName[2]
  	brokerNamespacedName := types.NamespacedName{
  	Name: brokerName,
  	Namespace: brokerNamespace,
  	}
  	broker, err := h.getBroker(brokerName, brokerNamespace)
  	if err != nil {
  	h.Logger.Warn("Failed to retrieve broker", zap.Error(err))
  	writer.WriteHeader(http.StatusBadRequest)
  	return
  	}
  	features := feature.FromContext(ctx)
  	if features.IsOIDCAuthentication() {
  	h.Logger.Debug("OIDC authentication is enabled")
  	err = h.tokenVerifier.VerifyJWTFromRequest(ctx, request, broker.Status.Address.Audience, writer)
  	if err != nil {
  	h.Logger.Warn("Error when validating the JWT token in the request", zap.Error(err))
  	return
  	}
  	h.Logger.Debug("Request contained a valid JWT. Continuing...")
  	}
  	ctx, span := trace.StartSpan(ctx, tracing.BrokerMessagingDestination(brokerNamespacedName))
  	defer span.End()
  	if span.IsRecordingEvents() {
  	span.AddAttributes(
  	tracing.MessagingSystemAttribute,
  	tracing.MessagingProtocolHTTP,
  	tracing.BrokerMessagingDestinationAttribute(brokerNamespacedName),
  	tracing.MessagingMessageIDAttribute(event.ID()),
  	)
  	span.AddAttributes(opencensusclient.EventTraceAttributes(event)...)
  	}
  	reporterArgs := &ReportArgs{
  	ns: brokerNamespace,
  	broker: brokerName,
  	eventType: event.Type(),
  	}
  	if request.TLS != nil {
  	reporterArgs.eventScheme = "https"
  	} else {
  	reporterArgs.eventScheme = "http"
  	}
  	statusCode, dispatchTime := h.receive(ctx, utils.PassThroughHeaders(request.Header), event, broker)
  	if dispatchTime > kncloudevents.NoDuration {
  	_ = h.Reporter.ReportEventDispatchTime(reporterArgs, statusCode, dispatchTime)
  	}
  	_ = h.Reporter.ReportEventCount(reporterArgs, statusCode)
  	writer.WriteHeader(statusCode)
  	// EventType auto-create feature handling
  	if h.EvenTypeHandler != nil {
  	h.EvenTypeHandler.AutoCreateEventType(ctx, event, toKReference(broker), broker.GetUID())
  	}
  	}

[Cali0707]

/good-first-issue

[knative-prow]

@Cali0707:
This request has been marked as suitable for new contributors.

Please ensure the request meets the requirements listed here.

If this request no longer meets these requirements, the label can be removed
by commenting with the /remove-good-first-issue command.

In response to this:

/good-first-issue

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[ckcd]

@Cali0707 may I take this?

[rahulii]

/assign

[Cali0707]

/close

Hey @rahulii we have made some changes to the design of the larger feature and this issue is no longer needed. Feel free to pick up another open issue and ask us for help on slack. Same goes for you @ckcd - if you want to work on any open unassigned issues all you need to do is comments /assign on the issue