Update Azure S2S Gateway IP Address

updateS2S.ps1

Param (
    [string]$userName = "svc_network-updater@yourDomain.onmicrosoft.com",
    [string]$password = "MyPassword#12345",
    [string]$subscriptionName = "mySubscription",
    [string]$resourceGroup = "Networking-US-East-2",
    [string]$localGatewayName = "LocalGateway-HQ",
    [string]$location = "East US 2",
    [string]$lgwSubnetPrefix = "192.168.0.0/21"
)

#region Login to Azure
    $securePassword = ConvertTo-SecureString -String $password -AsPlainText -Force
    $cred = New-Object System.Management.Automation.PSCredential($userName, $securePassword)
    Login-AzureRmAccount -Credential $cred -SubscriptionName $subscriptionName
    $subscription =  (Get-AzureRmSubscription | Where-Object {$_.SubscriptionName -eq $subscriptionName}).SubscriptionId
    Select-AzureRmSubscription -Subscriptionid $subscription
#endregion

function Update-Logs ($content) {
    $logPath = 'C:\S2S Logs'
    if (-not (Test-Path -Path $logPath)) {New-Item -Path $logPath -ItemType Directory}
    $date = Get-Date 
    $lastMonth = $date.AddMonths(-1)
    $fileName = $date.ToString("yyyy-MM-dd") + "- S2S Log.txt"
    $filePath = ($logPath + "\" + $fileName)
    $exists = Test-Path $filePath
    if ($exists) {
        $string = (Get-Date).ToShortTimeString().ToString() + "     $content"
        $string | Out-File -FilePath $filePath -Append
    }
    if (-not $exists) {
        $string | Out-File -FilePath $filePath
    }
    # Clean Up Logs Older than 1 month
    $items = Get-ChildItem -Path $logPath -Recurse -Filter *.txt | Where-Object {$_.CreationTime.Date -lt $lastMonth}
    $items | Remove-Item -Force
}

function Get-LocalIP {
    $wc = New-Object net.webclient
    $localIP = $wc.downloadstring("http://checkip.dyndns.com") -replace "[^\d\.]"

    return $localIP
}

function Get-LocalGatewayIP ($resourceGroup, $localGatewayName) {
    $lng = Get-AzureRmLocalNetworkGateway -Name $localGatewayName -ResourceGroupName $resourceGroup

    return $lng.GatewayIpAddress
 }

function Update-LocalGateway ($resourceGroup, $localGatewayName, $localIP, $location, $addressPrefix) {
    $localGateway = New-AzureRmLocalNetworkGateway -Name $localGatewayName `
                        -ResourceGroupName $resourceGroup `
                        -Location $location `
                        -GatewayIpAddress $localIP `
                        -AddressPrefix $addressPrefix `
                        -Force `
                        -Confirm:$false
    Write-Output("$localGatewayName Local Gateway updated...")  
}

function Connect-LocalGateway {
    $connections = (Get-VpnS2SInterface).Name
    foreach ($connection in $connections) {
        Connect-VpnS2SInterface -Name $connection
    }
    Update-Logs -content ((Get-VpnS2SInterface).Name.toString() + "-" + (Get-VpnS2SInterface).ConnectionState.toString())
}

#region Execute
    # Get Local IP Address Endpoint
    $localIP = Get-LocalIP
    # Get Azure Local Gateway IP Address
    $gatewayIP = Get-LocalGatewayIP -resourceGroup $resourceGroup -localGatewayName $localGatewayName
    # Update Log File
    Update-Logs -content ("Gateway IP = $gatewayIP and Local IP = $localIP")
    # If IP Addresses don't match update Azure Local Gateway IP Address
    If ($gatewayIP -ne $localIP) {
        Update-LocalGateway -resourceGroup $resourceGroup `
                            -localGatewayName $localGatewayName `
                            -localIP $localIP `
                            -location $location `
                            -addressPrefix $lgwSubnetPrefix
        Update-Logs -content ("Azure Local Gateway Updated")
    }
    # Make sure all RRAS connections are connected.
    Connect-LocalGateway
#endregion