Update multiple DNS records with CSV and foreach loop

PowerShell Help
1
Hi,

I am trying to update multiple DNS records using a CSV file and a foreach loop. Adding multiple records with CSV and foreach loop works fine.

CSV file (file.csv):

name,ip
test1,10.10.105.240
test2,10.10.105.241
test3,10.10.105.242
test4,10.10.105.243

Working addition of records:

Import-Csv .\file.csv | foreach {

	Add-DnsServerResourceRecordA `
	-Name $_.name `
	-ZoneName example.com `
	-IPv4Address $_.ip

	}

I can update individual records as:

$old = Get-DnsServerResourceRecord -ZoneName example.com -Name test1
$new = $old.Clone()
$new.RecordData.IPv4Address = [System.Net.IPAddress]::parse('10.10.106.35')
Set-DnsServerResourceRecord -NewInputObject $new -OldInputObject $old -ZoneName example.com

However, trying to incorporate the update into a CSV and foreach loop ends up adding additional records (2 records for test1, test2, etc., one record with original IP and one record with new IP):

CSV file:

name,ip
test1,10.10.106.240
test2,10.10.106.241
test3,10.10.106.242
test4,10.10.106.243

Non working code that creates additional records with new IP:

Import-Csv .\file.csv | foreach {

	$old = Get-DnsServerResourceRecord -ZoneName example.com -Name $_.name
	$new = $old.Clone()
	$new.RecordData.IPv4Address = [System.Net.IPAddress]::parse('$_.ip')
	Set-DnsServerResourceRecord -NewInputObject $new -OldInputObject $old -ZoneName example.com

	}

Can anyone shed some light on my mistake here?

Thanks,

HB

2
Well, it looks like the resolution was indeed simple. Removing the single quotes from the 'parse' argument allows the loop to succeed: 
Import-Csv .\file.csv | foreach {

$old = Get-DnsServerResourceRecord -ZoneName example.com -Name $.name

$new = $old.Clone()

$new.RecordData.IPv4Address = [System.Net.IPAddress]::parse($.ip)

Set-DnsServerResourceRecord -NewInputObject $new -OldInputObject $old -ZoneName example.com


}

I’m open to any suggestions if there is a better way to do this…

Thanks,

HB

3

Just to add some education to this. Single quotes are verbatim strings (no interpolation), so in the ‘$_.ip’ is literally that string not the ip property of the current item in the foreach-object loop. Recommend reviewing Get-Help about_quoting_rules