functions/Add-DbaRegisteredServer.ps1

#ValidationTags#Messaging,FlowControl,Pipeline,CodeStyle#
function Add-DbaRegisteredServer {
    <#
        .SYNOPSIS
            Adds registered servers to SQL Server Central Management Server (CMS)
 
        .DESCRIPTION
            Adds registered servers to SQL Server Central Management Server (CMS). If you need more flexiblity, look into Import-DbaRegisteredServer which
            accepts multiple kinds of input and allows you to add reg servers from different CMSes.
 
        .PARAMETER SqlInstance
            The target SQL Server instance
 
        .PARAMETER SqlCredential
            Login to the target instance using alternative credentials. Windows and SQL Authentication supported. Accepts credential objects (Get-Credential)
 
        .PARAMETER ServerName
            Server Name is the actual SQL instance name (labeled Server Name)
 
        .PARAMETER Name
            Name is basically the nickname in SSMS CMS interface (labeled Registered Server Name)
 
        .PARAMETER Description
            Adds a description for the registered server
 
        .PARAMETER Group
            Adds the registered server to a specific group.
 
        .PARAMETER InputObject
            Allows the piping of a registered server group
 
        .PARAMETER WhatIf
            Shows what would happen if the command were to run. No actions are actually performed.
 
        .PARAMETER Confirm
            Prompts you for confirmation before executing any changing operations within the command.
 
        .PARAMETER EnableException
            By default, when something goes wrong we try to catch it, interpret it and give you a friendly warning message.
 
            This avoids overwhelming you with "sea of red" exceptions, but is inconvenient because it basically disables advanced scripting.
 
            Using this switch turns this "nice by default" feature off and enables you to catch exceptions with your own try/catch.
 
        .NOTES
            Author: Chrissy LeMaire (@cl)
            Tags: RegisteredServer, CMS
 
            Website: https://dbatools.io
            Copyright: (C) Chrissy LeMaire, clemaire@gmail.com
            License: MIT https://opensource.org/licenses/MIT
 
        .LINK
            https://dbatools.io/Add-DbaRegisteredServer
 
        .EXAMPLE
           Add-DbaRegisteredServer -SqlInstance sql2008 -ServerName sql01
 
           Creates a registered server on sql2008's CMS which points to the SQL Server, sql01. When scrolling in CMS, the name "sql01" will be visible.
 
        .EXAMPLE
           Add-DbaRegisteredServer -SqlInstance sql2008 -ServerName sql01 -Name "The 2008 Clustered Instance" -Description "HR's Dedicated SharePoint instance"
 
           Creates a registered server on sql2008's CMS which points to the SQL Server, sql01. When scrolling in CMS, "The 2008 Clustered Instance" will be visible.
           Clearly this is hard to explain ;)
 
        .EXAMPLE
           Add-DbaRegisteredServer -SqlInstance sql2008 -ServerName sql01 -Group hr\Seattle
 
           Creates a registered server on sql2008's CMS which points to the SQL Server, sql01. When scrolling in CMS, the name "sql01" will be visible within the Seattle group which is in the hr group.
 
        .EXAMPLE
           Get-DbaRegisteredServerGroup -SqlInstance sql2008 -Group hr\Seattle | Add-DbaRegisteredServer -ServerName sql01111
 
           Creates a registered server on sql2008's CMS which points to the SQL Server, sql01. When scrolling in CMS, the name "sql01" will be visible within the Seattle group which is in the hr group.
    #>

    [CmdletBinding(SupportsShouldProcess)]
    param (
        [Alias("ServerInstance", "SqlServer")]
        [DbaInstanceParameter[]]$SqlInstance,
        [PSCredential]$SqlCredential,
        [parameter(Mandatory)]
        [string]$ServerName,
        [string]$Name = $ServerName,
        [string]$Description,
        [object]$Group,
        [parameter(ValueFromPipeline)]
        [Microsoft.SqlServer.Management.RegisteredServers.ServerGroup[]]$InputObject,
        [switch]$EnableException
    )
    process {
        if (-not $InputObject -and -not $SqlInstance) {
            Stop-Function -Message "You must either pipe in a registered server group or specify a sqlinstance"
            return
        }
        
        # double check in case a null name was bound
        if (-not $Name) {
            $Name = $ServerName
        }
        
        foreach ($instance in $SqlInstance) {
            if (($Group)) {
                if ($Group -is [Microsoft.SqlServer.Management.RegisteredServers.ServerGroup]) {
                    $InputObject += Get-DbaRegisteredServerGroup -SqlInstance $instance -SqlCredential $SqlCredential -Group $Group.Name
                }
                else {
                    $InputObject += Get-DbaRegisteredServerGroup -SqlInstance $instance -SqlCredential $SqlCredential -Group $Group
                }
            }
            else {
                $InputObject += Get-DbaRegisteredServerGroup -SqlInstance $instance -SqlCredential $SqlCredential -Id 1
            }

            if (-not $InputObject) {
                Stop-Function -Message "No matching groups found on $instance" -Continue
            }
        }

        foreach ($reggroup in $InputObject) {
            $parentserver = Get-RegServerParent -InputObject $reggroup

            if ($null -eq $parentserver) {
                Stop-Function -Message "Something went wrong and it's hard to explain, sorry. This basically shouldn't happen." -Continue
            }

            $server = $parentserver.ServerConnection.SqlConnectionObject

            if ($Pscmdlet.ShouldProcess($parentserver.SqlInstance, "Adding $ServerName")) {
                try {
                    $newserver = New-Object Microsoft.SqlServer.Management.RegisteredServers.RegisteredServer($reggroup, $Name)
                    $newserver.ServerName = $ServerName
                    $newserver.Description = $Description
                    $newserver.Create()

                    Get-DbaRegisteredServer -SqlInstance $server -Name $Name -ServerName $ServerName
                }
                catch {
                    Stop-Function -Message "Failed to add $ServerName on $($parentserver.SqlInstance)" -ErrorRecord $_ -Continue
                }
            }
        }
    }
}