Ambassador k8s- Edge stack listener

Question

I've started to have a look at the tutorials of Edge Stack - Embassador for deploying an Ingress. More concretely: https://www.getambassador.io/docs/edge-stack/latest/tutorials/getting-started

I don't understand the purpose of the listeners. If I have created a pod with a container which listens on the port 8080 and its associated service which listens on port 80 and its target port is 8080, why I should create a listener on port 8080 in Ambassador.

I understand that the behavior should be:

1. I hit the embassador service (port 80)
2. Embassador service redirects this request to the service of the demo (quote) app (port 80)
3. The service redirects the request to container (port 8080)

Could you help me to understand the concept of listeners in Ambassador?

Thanks

Answer 1

An Ambassador container is a sidecar container that is in charge of proxying connections from the application container to other services, actually the Ambassador container acts as a client proxy. In case of Ambassador Edge Stack, The Listener CRD tells Ambassador Edge Stack what port to listen on.