[Feature request] Proxy Support

[2xyo]

• Operating System Version: Debian GNU/Linux 9.5 (stretch)
• Provider (VirtualBox/VMWare): Virtualbox
• Vagrant Version: 2.1.5
• Packer Version: v1.3.1
• Is the issue reproducible or intermittent? reproducible

Description of the issue:

Hi team,

There is a possibility to add a proxy option? (as it's common in corporate environment)

Thanks in advance

Example of build failing because of the proxy not configured

==> virtualbox-iso: Provisioning with shell script: ./scripts/vm-guest-tools.bat
    virtualbox-iso:
    virtualbox-iso: C:\Users\vagrant>if not exist "C:\Windows\Temp\7z920-x64.msi" (powershell -Command "Start-Sleep 5; Invoke-WebRequest -Uri 'https://astuteinternet.dl.sourceforge.net/project/sevenzip/7-Zip/9.20/7z920-x64.msi' -Outfile 'C:\Windows\Temp\7z920-x64.msi'"  0<NUL )
    virtualbox-iso:
    virtualbox-iso: Invoke-WebRequest : Unable to connect to the remote server
    virtualbox-iso: At line:1 char:16
    virtualbox-iso: + ... rt-Sleep 5; Invoke-WebRequest -Uri 'https://astuteinternet.dl.sourcef ...
    virtualbox-iso: C:\Users\vagrant>if not exist "C:\Windows\Temp\7z920-x64.msi" (powershell -Command "Start-Sleep 5; Invoke-WebRequest -Uri 'http://www.7-zip.org/a/7z920-x64.msi' -Outfile 'C:\Windows\Temp\7z920-x64.msi')"  0<NUL )
    virtualbox-iso: +                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    virtualbox-iso:     + CategoryInfo          : InvalidOperation: (System.Net.HttpWebRequest:HttpWebRequest) [Invoke-WebRequest], WebExc
    virtualbox-iso:    eption
    virtualbox-iso:     + FullyQualifiedErrorId : WebCmdletWebResponseException,Microsoft.PowerShell.Commands.InvokeWebRequestCommand
    virtualbox-iso:
    virtualbox-iso:

[clong]

Hello,

This is not an issue I can control as it depends on Packer and Vagrant including support for proxy settings. Here is an issue I found related to proxy settings with Packer that may help: hashicorp/packer#2999

[2xyo]

Thanks for the reply. IMHO, it's not an issue with Packer or Vagrant, but it's more an issue with the configuration of the VM.

It's possible to handle a proxy during the build:

• with a plugin like http://tmatilai.github.io/vagrant-proxyconf/ that configures the virtual machine to use specified proxies
• or with an update of scripts like this Proxy support and ability to disable using BITS boxcutter/windows#85