Update IIS bindings from sitecore SiteDefinitions file using powershell

UpdateIISBindings.ps1

param(
    [Parameter(Position=0,Mandatory=$true)]
    [Alias("Site")]
    $siteName,
    [Parameter(Position=1,Mandatory=$true)]
    $domain,
    [Parameter(Position=2)]
    $configPath = "App_Config\Include\zzz\Project.SiteDefinitions.config"
    [Parameter(Position=3)]
    $xpath = "/configuration/sitecore/sites/site"
)


if($null -eq $siteName -or $siteName -eq "")
{
    $siteName = $($env:WebsiteName)
}

if($null -eq $domain -or $domain -eq "")
{
    $domain = $($env:Domain)
}

if($null -eq $siteName -or $siteName -eq "")
{
    Write-Error "SiteName parameter is required"
}

if($null -eq $domain -or $domain -eq "")
{
    Write-Error "Domain parameter is required"
}

Import-Module WebAdministration

$rootPath = Get-ItemProperty "IIS:\Sites\$($siteName)" -Name physicalPath
Write-Host "Physical path for site: '$($siteName)' is: '$($rootPath)'"

$certificate = Get-ChildItem -Path Cert:\LocalMachine\My | where-Object {$_.subject -like "*$domain*"}
Write-Host "Certificate thumbprint for domain: '$($domain)' is: '$($certificate.Thumbprint)'"

$path = Join-Path $rootPath $configPath

Write-Host "Loading '$path'"
[xml]$xml = Get-Content $path
$nodes = $xml.SelectNodes($xpath)

foreach($node in $nodes)
{
    $header = $node.Attributes["targetHostName"].Value

    if ($null -eq (Get-WebBinding -name $siteName -Protocol http -HostHeader $header))
    {
        New-WebBinding -name $siteName -Protocol http -HostHeader $header -IPAddress "*" -Port 80
        Write-Host "Created HTTP binding for: '$header'"
    }
    else {
        Write-Host "HTTP Binding for: '$header' already exists"
    }

    if ($null -eq (Get-WebBinding -name $siteName -Protocol https -HostHeader $header))
    {
        New-Item -Path "IIS:\SslBindings\*!443!${header}" -Thumbprint $($certificate.Thumbprint) -SSLFlags 1
        Write-Host "Created SSL binding for: '$header'"

        New-WebBinding -name $siteName -Protocol https -HostHeader $header -IPAddress "*" -Port 443 -SslFlags 1
        Write-Host "Created HTTPS binding for: '$header'"
    }
    else {
        Write-Host "HTTPS Binding for: '$header' already exists"
    }
}