Proxy support has been added in CDK vagrant box and in vagrant-registration plugin.
We should make sure our CDK tooling supports it too.
In order to run CDK behind proxy, we need to set environment variables: https://github.com/projectatomic/adb-atomic-developer-bundle/blob/master/docs/installing.adoc#setting-up-adb-behind-an-http-proxy

Eclipse Proxy Testing link: https://mojo.redhat.com/docs/DOC-989982
+ to create a proxy test environment: https://gist.github.com/LalatenduMohanty/5062050ac78721eda9676bbc15ecfd25

Standard unix proxy environmet variable $http_proxy has different purpose then $PROXY that CDK uses. Comments from lmohanty@redhat.com:

lalatenduM: we exepect customers workstation is configured to porixy server 
that means when you ping subscription-rhn-redhat-com.edge.prod.ext.phx2.redhat.com it should work 
lalatenduM: on a customer worksttaion 
lalatenduM: now teh challenge is to make openshift , docker and subscription manager in CDK VM aware of proxy server information
lalatenduM: vagrant-registration uses subscription manager for registraton
lalatenduM: whenyou use https://github.com/projectatomic/adb-atomic-developer-bundle/blob/master/docs/using.rst#using-the-adb-behind-http-proxy it will make openshift, docker and vagrant-registration aware of proxy server info

in a mail on the 26th of October 2017 "Re: [openshift-sme] CDK: Usage behind proxy":

The CDK supports a number of methods to apply proxy configuration.

You can specify a few of these at startup using the “minishift start” command.

First, you can set the --http-proxy and/or --https-proxy to apply RHEL environment variables.

For Docker Pulls, you can specify environment variables that are applied to the Docker daemon using the --docker-env flag (HTTP_PROXY, HTTPS_PROXY, NO_PROXY).

There are additional considerations for builds as well that can be applied. Please see the following document on the proxy considerations:

https://docs.openshift.com/container-platform/3.6/install_config/http_proxies.html

• Andy