DNS Client Manifest with Server 2008 r2 support

check-dns-servers.ps1

#Take in the string environment variable Puppet sets for us, remove [ and ], whitespace and split on ,
[array]$dnsarray = $env:dnsservers -replace '[][]','' -replace '\s',''  -split ','

#We need to search registry for the connection name - prior to 2012 there is no WMI class with this info. 
$Searchpath = Get-ChildItem HKLM:\SYSTEM\CurrentControlSet\Control\Network\ -Recurse
$NetworkReg = $Searchpath | ForEach-Object { Get-ItemProperty $_.pspath} | Where-Object {$_.Name -eq $env:ifname}

#Correlete adapter to connection name with PnpInstanceID, then AdapterConfiguration with the adapter interfaceindex.
$Adapter = Get-WmiObject -Class Win32_NetworkAdapter | Where-Object {$_.PNPDeviceID -eq $NetworkReg.PnpInstanceID}
$AdapterConfig = Get-WmiObject -Class win32_networkadapterconfiguration -Filter "ipenabled = 'true'" -ComputerName localhost | Where-Object {$_.InterfaceIndex -eq $Adapter.InterfaceIndex }

$StrCurrentDNS = $AdapterConfig.DNSServerSearchOrder | Out-String
$StrPuppetDNS = $dnsarray | Out-String

#If strings match, we exit with a failure code, as we do not want the set command to run.
if ($StrCurrentDNS -eq $StrPuppetDNS) {
    Exit 1
}
#If strings do not match, we should exit success and have the set command run.
else {
    Exit 0
}

dnsclient.pp

#Manages DNS servers per NIC. 
#If you set $validate to false, it will not fail to apply if it cannot reach the DNS server.

class network_win::dnsclient (
  String[1] $interfacename = 'Prod',
  Enum['IPv4', 'IPv6'] $ipfamily = 'IPv4',
  Array[Stdlib::Compat::IP_Address] $dnsservers = ['8.8.8.8','8.8.4.4'],
  Boolean $validate = true,
) {

  if $facts['kernelmajversion'] >= '6.2' {

      dsc_xdnsserveraddress
        {'dns_servers':
          dsc_interfacealias => $interfacename,
          dsc_addressfamily  => $ipfamily,
          dsc_address        => $dnsservers,
          dsc_validate       => $validate,
        }
  }

  else {
      exec { 'Set DNS Servers':
        command     => file('network_win/set-dns-servers.ps1'),
        onlyif      => file('network_win/check-dns-servers.ps1'),
        environment => [ "dnsservers=$dnsservers", "ifname=$interfacename" ],
        provider    => powershell,
      }
  }
}

set-dns-servers.ps1

#Take in the string environment variable Puppet sets for us, remove [ and ], whitespace and split on , .
[array]$dnsarray = $env:dnsservers -replace '[][]','' -replace '\s',''  -split ','

#We need to search registry for the connection name - prior to 2012 there is no WMI class with this info. 
$Searchpath = Get-ChildItem HKLM:\SYSTEM\CurrentControlSet\Control\Network\ -Recurse
$NetworkReg = $Searchpath | ForEach-Object { Get-ItemProperty $_.pspath} | Where-Object {$_.Name -eq $env:ifname}
if ($NetworkReg -eq $null) {
    Write-Error -Message "Could not find interface name: $env:ifname in registry"
    Exit 1
}
Else {
    #Correlete adapter to connection name with PnpInstanceID, then AdapterConfiguration with the adapter interfaceindex.
    $Adapter = Get-WmiObject -Class Win32_NetworkAdapter | Where-Object {$_.PNPDeviceID -eq $NetworkReg.PnpInstanceID}
    $AdapterConfig = Get-WmiObject -Class win32_networkadapterconfiguration -Filter "ipenabled = 'true'" -ComputerName localhost | Where-Object {$_.InterfaceIndex -eq $Adapter.InterfaceIndex }
    $SetResult = $AdapterConfig.SetDNSServerSearchOrder($dnsarray)
    
    #If this evaluates true, our intended DNS servers were set correctly.
    if ($SetResult.ReturnValue -eq '0') {
        Exit 0
    }
    else {
        Exit 1
    }

}