Install-dotnet-ci.ps1

function install {
  $build_dir = Join-Path $PSScriptRoot ".build"
  $json = ConvertFrom-Json (Get-Content "$path/global.json" -Raw)
  $required_version = $json.sdk.version
  # If there's a version mismatch with what's defined in global.json then a 
  # call to dotnet --version will generate an error.
  try { dotnet --version 2>&1>$null } catch { $install_sdk = $true }
  # Different PS versions may throw an exception vs set LASTEXITCODE 
  if ($global:LASTEXITCODE) {
    $install_sdk = $true;
    $global:LASTEXITCODE = 0;
  }

  if ($install_sdk) {
    $installer = $null;
    if ($IsWindows) {
      $installer = "$build_dir/dotnet-installer.ps1" 
      (New-Object System.Net.WebClient).DownloadFile("https://dot.net/v1/dotnet-install.ps1", $installer);
    }
    else { 
      $installer = "$build_dir/dotnet-installer"
      write-host Downloading installer to $installer 
      # use curl on linux as WebClient.DownloadFile always throws an exception 
      curl https://dot.net/v1/dotnet-install.sh --output $installer 
      chmod +x $installer
    }

    $dotnet_path = "$path/.dotnetsdk"

    # If running in azure pipelines, use that as the dotnet install path. 
    if ($env:AGENT_TOOLSDIRECTORY) {
      $dotnet_path = Join-Path $env:AGENT_TOOLSDIRECTORY dotnet
    }

    Write-Host Installing $json.sdk.version to $dotnet_path
    . $installer -i $dotnet_path -v $json.sdk.version
  }
}