functions/Repair-DbaServerName.ps1

Function Repair-DbaServerName
{
<#
.SYNOPSIS
Renames @@SERVERNAME to match with the Windows name.
     
.DESCRIPTION
When a SQL Server's host OS is renamed, the SQL Server should be as well. This helps with Availability Groups and Kerberos.
 
This command renames @@SERVERNAME to match with the Windows name. The new name is automatically determined. It does not matter if you use an alias to connect to the SQL instance.
         
If the automatically determiend new name matches the old name, the command will not run.
     
https://www.mssqltips.com/sqlservertip/2525/steps-to-change-the-server-name-for-a-sql-server-machine/
     
.PARAMETER SqlInstance
The SQL Server that you're connecting to.
 
.PARAMETER Credential
Credential object used to connect to the SQL Server as a different user.
 
.PARAMETER Detailed
Specifies if the servername is updatable. If updatable -eq $false, it will return the reasons why.
 
.PARAMETER Force
By default, this command produces a ton of confirm prompts. Force bypasses many of these confirms, but not all.
 
.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 AutoFix
Automatically performs the fix
 
.NOTES
Tags: SPN
dbatools PowerShell module (https://dbatools.io, clemaire@gmail.com)
Copyright (C) 2016 Chrissy LeMaire
 
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
 
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 
You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>.
 
.LINK
https://dbatools.io/Repair-DbaServerName
 
.EXAMPLE
Repair-DbaServerName -SqlInstance sql2014
 
Checks to see if the server is updatable, prompts galore, changes name.
 
.EXAMPLE
Repair-DbaServerName -SqlInstance sql2014 -AutoFix
 
Even more prompts/confirms, but removes Replication or breaks mirroring if necessary.
 
.EXAMPLE
Repair-DbaServerName -SqlInstance sql2014 -AutoFix -Force
     
Skips some prompts/confirms but not all of them.
     
#>

    [CmdletBinding(SupportsShouldProcess = $true, ConfirmImpact = "High")]
    Param (
        [parameter(Mandatory = $true, ValueFromPipeline = $true)]
        [Alias("ServerInstance", "SqlServer")]
        [DbaInstanceParameter[]]$SqlInstance,
        [PSCredential]$Credential,
        [switch]$AutoFix,
        [switch]$Force
    )
    
    BEGIN
    {
        if ($Force -eq $true) { $ConfirmPreference = "None" }
    }
    
    PROCESS
    {
        foreach ($servername in $SqlInstance)
        {
            try
            {
                $server = Connect-SqlInstance -SqlInstance $servername -SqlCredential $Credential
            }
            catch
            {
                Write-Warning "Can't connect to $servername. Moving on."
                Continue
            }
            
            if ($server.isClustered)
            {
                
                Write-Warning "$servername is a cluster. Microsoft does not support renaming clusters."
                Continue
            }
            
            if ($server.VersionMajor -eq 8)
            {
                Write-Warning "SQL Server 2000 not supported. Skipping $servername."
                Continue
            }
            
            # Check to see if we can easily proceed
            Write-Verbose "Executing Test-DbaServerName to see if the server is in a state to be renamed. "
            
            $nametest = Test-DbaServerName $servername -Detailed -NoWarning
            $serverinstancename = $nametest.ServerInstanceName
            $SqlInstancename = $nametest.SqlServerName
            
            if ($nametest.RenameRequired -eq $false)
            {
                return "Good news! $serverinstancename's @@SERVERNAME does not need to be changed. If you'd like to rename it, first rename the Windows server."
            }
            
            if ($nametest.updatable -eq $false)
            {
                Write-Output "Test-DbaServerName reports that the rename cannot proceed with a rename in this $servername's current state."
                
                $nametest
                
                foreach ($nametesterror in $nametest.Blockers)
                {
                    if ($nametesterror -like '*replication*')
                    {
                        $replication = $true
                        
                        if ($AutoFix -eq $false)
                        {
                            throw "Cannot proceed because some databases are involved in replication. You can run exec sp_dropdistributor @no_checks = 1 but that may be pretty dangerous. Alternatively, you can run -AutoFix to automatically fix this issue. AutoFix will also break all database mirrors."
                        }
                        else
                        {
                            if ($Pscmdlet.ShouldProcess("console", "Prompt will appear for confirmation to break replication."))
                            {
                                $title = "You have chosen to AutoFix the blocker: replication."
                                $message = "We can run sp_dropdistributor which will pretty much destroy replication on this server. Do you wish to continue? (Y/N)"
                                $yes = New-Object System.Management.Automation.Host.ChoiceDescription "&Yes", "Will continue"
                                $no = New-Object System.Management.Automation.Host.ChoiceDescription "&No", "Will exit"
                                $options = [System.Management.Automation.Host.ChoiceDescription[]]($yes, $no)
                                $result = $host.ui.PromptForChoice($title, $message, $options, 1)
                                
                                if ($result -eq 1)
                                {
                                    throw "Cannot continue"
                                }
                                else
                                {
                                    Write-Output "`nPerforming sp_dropdistributor @no_checks = 1"
                                    $sql = "sp_dropdistributor @no_checks = 1"
                                    Write-Debug $sql
                                    try
                                    {
                                        $null = $server.Query($sql)
                                        Write-Output "Successfully executed $sql`n"
                                    }
                                    catch
                                    {
                                        Write-Exception $_
                                        throw $_
                                    }
                                }
                            }
                        }
                    }
                    elseif ($Error -like '*mirror*')
                    {
                        if ($AutoFix -eq $false)
                        {
                            throw "Cannot proceed because some databases are being mirrored. Stop mirroring to proceed. Alternatively, you can run -AutoFix to automatically fix this issue. AutoFix will also stop replication."
                        }
                        else
                        {
                            if ($Pscmdlet.ShouldProcess("console", "Prompt will appear for confirmation to break replication."))
                            {
                                $title = "You have chosen to AutoFix the blocker: mirroring."
                                $message = "We can run sp_dropdistributor which will pretty much destroy replication on this server. Do you wish to continue? (Y/N)"
                                $yes = New-Object System.Management.Automation.Host.ChoiceDescription "&Yes", "Will continue"
                                $no = New-Object System.Management.Automation.Host.ChoiceDescription "&No", "Will exit"
                                $options = [System.Management.Automation.Host.ChoiceDescription[]]($yes, $no)
                                $result = $host.ui.PromptForChoice($title, $message, $options, 1)
                                
                                if ($result -eq 1)
                                {
                                    Write-Output "Okay, moving on."
                                }
                                else
                                {
                                    Write-Output "Removing Mirroring"
                                    
                                    foreach ($database in $server.Databases)
                                    {
                                        if ($database.IsMirroringEnabled)
                                        {
                                            $dbname = $database.name
                                            
                                            try
                                            {
                                                Write-Output "Breaking mirror for $dbname"
                                                $database.ChangeMirroringState([Microsoft.SqlServer.Management.Smo.MirroringOption]::Off)
                                                $database.Alter()
                                                $database.Refresh()
                                            }
                                            catch
                                            {
                                                Write-Exception $_
                                                throw "Could not break mirror for $dbname. Skipping."
                                            }
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
            }
            # ^ That's embarassing
            
            $instancename = $instance = $server.InstanceName
            
            if ($instancename.length -eq 0)
            {
                $instancename = $instance = "MSSQLSERVER"
            }
            
            try
            {
                $allsqlservices = Get-Service -ComputerName $server.ComputerNamePhysicalNetBIOS -ErrorAction SilentlyContinue | Where-Object { $_.DisplayName -like "SQL*$instance*" -and $_.Status -eq "Running" }
            }
            catch
            {
                Write-Warning "Can't contact $servername using Get-Service. This means the script will not be able to automatically restart SQL services."
            }
            
            if ($nametest.Warnings.length -gt 0)
            {
                $reportingservice = Get-Service -ComputerName $server.ComputerNamePhysicalNetBIOS -DisplayName "SQL Server Reporting Services ($instance)" -ErrorAction SilentlyContinue
                
                if ($reportingservice.Status -eq "Running")
                {
                    if ($Pscmdlet.ShouldProcess($server.name, "Reporting Services is running for this instance. Would you like to automatically stop this service?"))
                    {
                        $reportingservice | Stop-Service
                        Write-Warning "You must reconfigure Reporting Services using Reporting Services Configuration Manager or PowerShell once the server has been successfully renamed."
                    }
                }
            }
            
            if ($Pscmdlet.ShouldProcess($server.name, "Performing sp_dropserver to remove the old server name, $SqlInstancename, then sp_addserver to add $serverinstancename"))
            {
                $sql = "sp_dropserver '$SqlInstancename'"
                Write-Debug $sql
                try
                {
                    $null = $server.Query($sql)
                    Write-Output "`nSuccessfully executed $sql"
                }
                catch
                {
                    Write-Exception $_
                    throw $_
                }
                
                $sql = "sp_addserver '$serverinstancename', local"
                Write-Debug $sql
                
                try
                {
                    $null = $server.Query($sql)
                    Write-Output "Successfully executed $sql"
                }
                catch
                {
                    Write-Exception $_
                    throw $_
                }
                $renamed = $true
            }
            
            if ($allsqlservices -eq $null)
            {
                Write-Warning "Could not contact $($server.ComputerNamePhysicalNetBIOS) using Get-Service. You must manually restart the SQL Server instance."
                $needsrestart = $true
            }
            else
            {
                if ($Pscmdlet.ShouldProcess($server.ComputerNamePhysicalNetBIOS, "Rename complete! The SQL Service must be restarted to commit the changes. Would you like to restart the $instancname instance now?"))
                {
                    try
                    {
                        Write-Output "`nStopping SQL Services for the $instancename instance"
                        $allsqlservices | Stop-Service -Force -WarningAction SilentlyContinue # because it reports the wrong name
                        Write-Output "Starting SQL Services for the $instancename instance"
                        $allsqlservices | Where-Object { $_.DisplayName -notlike "*reporting*" } | Start-Service -WarningAction SilentlyContinue # because it reports the wrong name
                    }
                    catch
                    {
                        Write-Exception $_
                        throw "Could not restart at least one SQL Service :("
                    }
                }
            }
            
            if ($renamed -eq $true)
            {
                Write-Output "`n$servername successfully renamed from $SqlInstancename to $serverinstancename"
            }
            
            if ($needsrestart -eq $true)
            {
                Write-Output "SQL Service restart for $serverinstancename still required"
            }
        }
    }
}