I was performing a POC with a customer and I think I might have found a bug in the Kafka Connect build process when using maven. It seems the steps that configures the mvn dependency:copy-depency is overriding the container NO_PROXY/HTTP_PROXY configuration.

Here is my example that runs fine in a cluster without proxy but fails in a cluster with proxy:
 
kafka-connect.spec.yml
 
and here is the step where it fails. This log was extracted from the build pod:

test-connect-cluster-connect-build-2-undefined.log
 
as you can see it is able to access maven registry using curl but it cannot do it using maven