Azure DevOps (VSTS) Get Azure WebApp DefaultHostName workaround

azure-devops-vsts-get-defaulthostname.ps1

    # Get-AzureRmWebApp does not work correctly when running under the Azure DevOps build server (October 2018).
    # Here is a workaround to get the DefaultHostName

    # Place your own name here:
    $appName = "myspecialappname-dev"
    
    $webApp = Get-AzureRmWebApp -ResourceGroupName $ResourceGroupName -Name $appName -ErrorAction Stop
    if (!$webApp) { Write-Error ("WebApp not found: {0} (Resource Group: {1})" -f $appName,$ResourceGroupName) }
    # DefaultHostName property does not work in the Azure DevOps (VSTS) build server, see: https://github.com/Azure/azure-powershell/issues/5760
    # The HostNames property works, so pick one of the hostnames instead of DefaultHostName:
    foreach ($name in $webApp.HostNames) {
        if ($name.ToLower().StartsWith($appName.ToLower())) {
            $hostname = $name;
            break;
        }
    }
    if (!$hostname) { Write-Error ("HostName not found for WebApp: {0} (Resource Group: {1})" -f $appName,$ResourceGroupName) }