Add optional proxy configuration to vagrant file

Vagrantfile

@@ -22,6 +22,13 @@ Vagrant.configure("2") do |config|
   config.vm.network "private_network", ip: "192.168.200.4", adapter: 2
   config.vm.hostname = "devbox.devops.detss.corpintra.net"
 
+  # proxy
+  if ENV.key?("http_proxy")
+    config.proxy.http = ENV["http_proxy"]
+    config.proxy.https = ENV["https_proxy"]
+    # config.proxy.no_proxy = "localhost,127.0.0.1"
+  end
+
   # requires additional vagrant plugin
   config.disksize.size = "20GB"