Add script for getting vcpkg tools behind a proxy

Currently the vcpkg executable downloads files directly from the network. Unfortunately it does not respect proxy environment variables. This downloads the files using those environment variables and stages them into the root.

Author: donny-dont

Download-VcpkgTools.ps1

@@ -0,0 +1,58 @@
+<#
+  .Synopsis
+  Downloads tools required by vcpkg.
+  .Details
+  At this time the `vcpkg` executable uses the system proxy settings, not the
+  values contained in the proxy environment variables. This script is a 
+  workaround until that is resolved
+  .Parameter ToolsPath
+  The XML file containing the tool listing.
+#>
+
+param(
+  [Parameter(Mandatory)]
+  [string]$toolsPath
+)
+
+$ErrorActionPreference = 'Stop';
+
+$downloads = @(
+  'powershell-core',
+  '7zip'
+);
+
+[xml]$document = Get-Content $toolsPath;
+$tools = $document.SelectNodes('//tool');
+
+Write-Host $document;
+$downloadPath = Join-Path $PSScriptRoot 'downloads';
+$toolsPath = Join-Path $downloadPath 'tools';
+
+if (!(Test-Path $downloadPath)) {
+  New-Item -ItemType 'directory' -Path $downloadPath;
+}
+
+foreach ($tool in $tools) {
+  if ($tool.os -eq 'windows') {
+    foreach ($download in $downloads) {
+      if ($tool.Name -eq $download) {
+        $toolName = $tool.name;
+        
+        # Download the tool
+        Write-Host ('Downloading {0} from {1}' -f $toolName, $tool.url);
+        $downloadTo = (Join-Path $downloadPath $tool.archiveName);
+        Invoke-WebFileRequest -url $tool.url -DestinationPath $downloadTo;
+        Write-Host('Downloaded {0} to {1}' -f $toolName, $downloadTo);
+        
+        # Extract the tool
+        $extractTo = (Join-Path $toolsPath ('{0}-{1}-windows' -f $toolName, $tool.version));
+        if ($toolName -eq '7zip') {
+           $extractTo = Join-Path $extractTo ($tool.exeRelativePath -split '\\')[0];
+        }
+        Write-Host('Extracting {0} from {1}' -f $toolName, $downloadTo);
+        Expand-7Zip -ArchiveFileName $downloadTo -TargetPath $extractTo;
+        Write-Host('Extracted {0} to {1}' -f $toolName, $extractTo);
+      }
+    }
+  }
+}