Running Chef Test-Kitchen behind Proxy on Windows 7

I am trying to run Test-Kitchen on a Windows 7 box, using Powershell, behind a corporate firewall (I'm following the tutorial at http://kitchen.ci/docs/getting-started/creating-cookbook). When I run:

PS C:\Users\jazzyb\Documents\git-cookbook> kitchen init --driver=kitchen-vagrant

I get

   identical  .kitchen.yml
   identical  chefignore
ERROR:  Could not find a valid gem 'kitchen-vagrant' (>= 0), here is why:
          Unable to download data from https://rubygems.org/ - Errno::ECONNREFUSED: No connection could be made because
the target machine actively refused it. - connect(2) for "api.rubygems.org" port 443 (https://api.rubygems.org/specs.4.8
.gz)
PS C:\Users\jazzyb\Documents\git-cookbook>

Despite the fact I can access that file using Invoke-WebRequest

PS C:\Users\jazzyb\Documents\git-cookbook> Invoke-WebRequest https://api.rubygems.org/specs.4.8.gz


StatusCode        : 200
StatusDescription : OK
Content           : {31, 139, 8, 0...}
RawContent        : HTTP/1.1 200 OK
                    x-amz-id-2: aVuWL3xWz9vwwto0GZE0uAJ4q8o8N+QsIC9QUJmO63mVNxY95pv994RHuQFrdaCCtvADJSaOOfo=
                    x-amz-request-id: CC71B064EACA4126
                    x-amz-version-id: 4Q20EeykLoACN7Ko3b9Bqw1cARiGEbaI
                    x-amz...
Headers           : {[x-amz-id-2, aVuWL3xWz9vwwto0GZE0uAJ4q8o8N+QsIC9QUJmO63mVNxY95pv994RHuQFrdaCCtvADJSaOOfo=],
                    [x-amz-request-id, CC71B064EACA4126], [x-amz-version-id, 4Q20EeykLoACN7Ko3b9Bqw1cARiGEbaI],
                    [x-amz-meta-surrogate-key, full-index]...}
RawContentLength  : 2626893

Setting the proxy directly doesn't seem to work either

PS C:\Users\jazzyb\Documents\git-cookbook> kitchen init --driver=kitchen-vagrant --http_proxy=http://proxy.somecorp.com:80/

Am I missing something obvious?

Solution

Export the http_proxy, HTTP_PROXY, https_proxy, and HTTPS_PROXY environment variables. Rubygems doesn't directly supports Windows' proxy configuration system, you need to do it the Unix way.