In some situation, the Kafka cluster might be runnign behing a HTTP proxy. In geenral that should not be a problem since the compoenents in general don't communicate with open internet. But there are some cases it might be useful to support such environments for example:

• Kafka Connect running connectors which pull/push data from/to outside through the proxy
• Maybe also JMXTrans pushing the data or OAuth authentication talking with OAuth server from behind the proxy

The usual environment variables - HTTP_PROXY, HTTPS_PROXY and NO_PROXY can be passed to the Cluster operator which will in turn set them on all created containers. This is also in sync with OpenShift Operator Hub which sets these environment variables automatically when proxy is configured in the cluster.