Modify DNS records with idempotence

DNS-Adjustments.ps1

function Adjust-DNSServerResourceRecord {
    param(
        [Parameter(Mandatory=$true)][string]$ZoneName,
        [Parameter(Mandatory=$true)][string]$Name,
        [Parameter(Mandatory=$true)][string]$RRType,
        [Parameter(Mandatory=$true)]$Data,
        $TimeToLive = $null
    )

    # Initialize local variables
    $dnsRecordTypesRetrieval = @{
        'CNAME' = 'HostNameAlias';
        'A' = @('IPv4Address', 'IPAddressToString')
    }
    $dnsRecordTypesCreation = @{
        'CNAME' = @{
            "CName" = $true;
            "HostNameAlias" = $null
        };
        'A' = @{
            "A" = $true;
            "IPv4Address" = $null
        }
    }
    $dnsRecordTypesCreationKeys = @{
        'CNAME' = 'HostNameAlias';
        'A' = 'IPv4Address'
    }

    # Find the DNS server address and the default RR TTL
    $dnsSOARecords = @(Resolve-DnsName -Type SOA -Name $ZoneName)
    $dnsServer = $dnsSOARecords[0].PrimaryServer
    $dnsTTL = $dnsSOARecords[0].DefaultTTL

    # Validate function arguments
    if (-not ($dnsRecordTypesRetrieval.ContainsKey($RRType))) {
        throw ("Invalid RRtype: '" + $RRType + "'")
    }
    if (-not $TimeToLive) {
        $TimeToLive = New-TimeSpan -Seconds $dnsTTL
    }

    # Check whether or not DNS records need update
    try {
        $dnsRecords = Get-DnsServerResourceRecord `
            -ComputerName $dnsServer `
            -ZoneName $ZoneName `
            -Name $Name `
            -RRType $RRType `
            -Node
        if ((@($dnsRecords) | Where-Object { $_.TimeToLive -ne $TimeToLive }).length -eq 0) {
            $dnsRecords = $dnsRecords | Select -ExpandProperty RecordData
            foreach ($property in @($dnsRecordTypesRetrieval[$RRType])) {
                $dnsRecords = $dnsRecords | Select-Object -ExpandProperty $property
            }
            if ($dnsRecords) {
                if (-not (Compare-Object -ReferenceObject $dnsRecords -DifferenceObject $Data)) {
                    return
                }
            }
        }
    } finally {
    }

    # DNS records do need update. Delete old records...
    try {
        Get-DnsServerResourceRecord `
            -ComputerName $dnsServer `
            -ZoneName $ZoneName `
            -Name $Name `
            -Node | `
        Select -Unique -ExpandProperty RecordType | ForEach-Object {
            try {
                Remove-DnsServerResourceRecord `
                    -ComputerName $dnsServer `
                    -ZoneName $ZoneName `
                    -Name $Name `
                    -RRType $_ `
                    -Force
                Write-Warning ("Removed '" + $Name + "." + $ZoneName + " " + $_ + "'...")
            } catch {
                Write-Error $_
            }
        }
    } finally {
    }

    # ...and create new ones.
    foreach ($item in @($Data)) {
        $params = $dnsRecordTypesCreation[$RRType]
        $params[$dnsRecordTypesCreationKeys[$RRType]] = $item
        try {
            $newDNSRecord = Add-DnsServerResourceRecord `
                -ComputerName $dnsServer `
                -ZoneName $ZoneName `
                -Name $Name `
                @params `
                -TimeToLive $TimeToLive `
                -PassThru
            Write-Warning ("Added '" + $Name + "." + $ZoneName + " " + $newDNSRecord.TimeToLive.TotalSeconds + " " + $RRType + " " + $item + "'...")
        } catch {
            Write-Error $_
        }
    }
}

Adjust-DNSServerResourceRecord -ZoneName adatum.com -Name test -RRType A -Data 172.16.1.245,172.24.0.1
Adjust-DNSServerResourceRecord -ZoneName adatum.com -Name testalias -RRType CNAME -Data test.adatum.com. -TimeToLive 0:2:0