HTTP trigger - is the Host header ignored?

[fabricebrito]

I want to use the HTTP trigger to POST requests to knative serving services. For that I need to set the Host header:

triggers:
    - template:
        name: http-trigger
        http:
          url: http://knative-local-gateway.istio-system.svc.cluster.local/ns1/cool-endpoint
          headers:
            accept: application/json
            Content-Type: application/json
            Host: execute.cool-api.example.com

The trigger logs policy application resulted in failure. http response status 404 is not allowed

This works:

kubectl run -it --rm test-curl --image=curlimages/curl -- curl -H "Host: execute.cool-api.example.com" http://knative-local-gateway.istio-system.svc.cluster.local/ns1/cool-endpoint

My guess is that the http client used sets the Host and doesn't allow setting it via the trigger configuration.

Is my guess correct or am I doing something wrong?

Could this be a feature request for Argo Events HTTP trigger?

[fabricebrito]

Looking at

argo-events/pkg/sensors/triggers/http/http.go

Lines 148 to 152 in 9e888c7

	if trigger.Headers != nil {
	for name, value := range trigger.Headers {
	request.Header[name] = []string{value}
	}
	}

I think request.Host and request.URL.Host (not sure it's needed) should be set if Host is in trigger.Headers