From 354c5e5975c6124b23c646d3ed8a04f6e1e88490 Mon Sep 17 00:00:00 2001
From: Pierangelo Di Pilato <pierdipi@redhat.com>
Date: Thu, 29 Jun 2023 15:03:02 +0200
Subject: [PATCH] Send namespace header in MT components (#3184)

When running MT components [1] in mesh mode with Istio,
we lose the ability to define fine grained policies since we
don't know the resource namespace that originated such
request, therefore, by having a `Kn-Namespace` header,
in mesh mode, users case define fine-grained policies and
isolate namespaces.

[1] KafkaSource, Kafka Broker, and KafkaChannel

Signed-off-by: Pierangelo Di Pilato <pierdipi@redhat.com>
---
 .../dispatcher/impl/http/WebClientCloudEventSender.java       | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/data-plane/dispatcher/src/main/java/dev/knative/eventing/kafka/broker/dispatcher/impl/http/WebClientCloudEventSender.java b/data-plane/dispatcher/src/main/java/dev/knative/eventing/kafka/broker/dispatcher/impl/http/WebClientCloudEventSender.java
index 6f9ad9879a..16836ddad1 100644
--- a/data-plane/dispatcher/src/main/java/dev/knative/eventing/kafka/broker/dispatcher/impl/http/WebClientCloudEventSender.java
+++ b/data-plane/dispatcher/src/main/java/dev/knative/eventing/kafka/broker/dispatcher/impl/http/WebClientCloudEventSender.java
@@ -167,7 +167,9 @@ private Future<?> send(final CloudEvent event, final Promise<HttpResponse<Buffer
     return VertxMessageFactory
       .createWriter(client.postAbs(target)
         .timeout(this.consumerVerticleContext.getEgressConfig().getTimeout() <= 0 ? DEFAULT_TIMEOUT_MS : this.consumerVerticleContext.getEgressConfig().getTimeout())
-        .putHeader("Prefer", "reply"))
+        .putHeader("Prefer", "reply")
+        .putHeader("Kn-Namespace", this.consumerVerticleContext.getEgress().getReference().getNamespace())
+      )
       .writeBinary(event)
       .onFailure(ex -> {
         logError(event, ex);