bootstrap.ps1

####################################################
# Function definitions
####################################################

# Retry a command 5 times or until successful, whichever comes first.
function Retry-Command {
    [CmdletBinding()]
    Param(
        [Parameter(Position=0, Mandatory=$true)]
        [scriptblock]$ScriptBlock,

        [Parameter(Position=1, Mandatory=$false)]
        [int]$Maximum = 5
    )

    Begin {
        $cnt = 0
    }

    Process {
        do {
            $cnt++
            try {
                $ScriptBlock.Invoke()
                return
            } catch {
                Write-Error $_.Exception.InnerException.Message -ErrorAction Continue
            }
        } while ($cnt -lt $Maximum)

        # Throw an error after $Maximum unsuccessful invocations. Doesn't need
        # a condition, since the function returns upon successful invocation.
        throw 'Execution failed.'
    }
}

# Define a quick recursive function to kill the px process tree.
function Kill-Tree {
    Param([int]$ppid)
    Get-CimInstance Win32_Process | Where-Object { $_.ParentProcessId -eq $ppid } | ForEach-Object { Kill-Tree $_.ProcessId }
    Stop-Process -Id $ppid
}

####################################################
# Main script
####################################################

$ErrorActionPreference = "stop"

$cygwin_dir = "$env:LOCALAPPDATA/cygwin64"

mkdir $cygwin_dir -ErrorAction Stop

Write-Output ""
Write-Output "Downloading Cygwin"

# Use px to allow UNIX-y programs that don't speak NTML to connect to the internet through the corporate proxies.
# See https://github.com/genotrance/px for more information
$px = $(Start-Process -NoNewWindow -PassThru ./dist/px.exe)
$env:http_proxy="http://localhost:3128"
$env:https_proxy="http://localhost:3128"

[Net.ServicePointManager]::SecurityProtocol = "tls12, tls11, tls"
$proxy = New-Object System.Net.WebProxy($env:http_proxy)
$wc = new-object system.net.WebClient
$wc.proxy = $proxy

# Retry connecting to cygwins website just in case px takes a few to start up
Retry-Command {
    $wc.DownloadFile('https://cygwin.com/setup-x86_64.exe',"$cygwin_dir/setup-x86_64.exe")
}

Write-Output "Installing cygwin"
& "$cygwin_dir/setup-x86_64.exe" `
    --quiet-mode `
    --no-admin `
    --no-desktop `
    --site "http://mirrors.kernel.org/sourceware/cygwin/" `
    --root "$cygwin_dir" `
    --local-package-dir "$cygwin_dir/pkg" `
    --verbose `
    --prune-install `
    --packages wget,rsync,curl,lynx `
| Out-Null

Add-Content "$cygwin_dir/etc/nsswitch.conf" "db_home: /cygdrive/c/Users/%U"

# Export the BofA public CA certificates from the system store, and PEM encode them so UNIX-y programs
# like Git Bash can use them. This allows Git to clone from Horizon over HTTPS without needing to disable SSL.
$cert_dir = "$cygwin_dir/certs"
mkdir $cert_dir
$(Get-ChildItem -Path cert:\LocalMachine\Root -Recurse) + $( Get-ChildItem -Path cert:\LocalMachine\CA -Recurse) |
        Where-Object {
            $_.notafter -gt (Get-Date) -AND !$_.hasprivatekey
        } |
        Sort-Object -property thumbprint -unique |
        ForEach-Object {
            Export-Certificate -Cert $_ -FilePath "$cert_dir/$($_.thumbprint).cer"
            & "$cygwin_dir/bin/openssl.exe" x509 -inform DER -in "$cert_dir/$($_.thumbprint).cer" -outform PEM -out "$cygwin_dir/etc/pki/ca-trust/source/anchors/$($_.thumbprint).pem"
        }

# Run the Cywgin setup bash scripts since I'm better at bash than powershell.
Write-Output "Running scripts"
$env:CHERE_INVOKING=1
& "$cygwin_dir/bin/bash" --login ./setup.bash

# Kill px when we are done.
Kill-Tree $px.id