Use scheduled task replication via source DC session

certy.ps1

@@ -266,6 +266,7 @@ function Invoke-Replication {
         [string]$Command,
         [bool]$UseRemote,
         [pscredential]$Credential,
+        [string]$SourceDc,
         [scriptblock]$Log
     )
 
@@ -276,47 +277,61 @@ function Invoke-Replication {
         return
     }
 
-    $sessions = @{}
+    if ([string]::IsNullOrWhiteSpace($SourceDc)) {
+        & $Log "Replication skipped: source DC is empty."
+        return
+    }
+
+    $session = $null
     try {
+        if ($UseRemote) {
+            try {
+                if ($Credential) {
+                    $session = New-PSSession -ComputerName $SourceDc -Credential $Credential -ErrorAction Stop
+                } else {
+                    $session = New-PSSession -ComputerName $SourceDc -ErrorAction Stop
+                }
+                & $Log "Replication session opened: $SourceDc"
+            } catch {
+                & $Log ("Replication session error on {0}: {1}" -f $SourceDc, $_.Exception.Message)
+                return
+            }
+        }
+
         foreach ($server in $targets) {
-            $usesToken = $Command -match "\{server\}"
+            $usesToken = $Command -match "\{server\}|\{dest\}"
-            $cmd = if ($usesToken) { $Command.Replace("{server}", $server) } else { $Command }
+            $cmd = $Command.Replace("{server}", $server).Replace("{dest}", $server)
             $cmd = $cmd.Trim()
             if ($cmd -match "^(?i)\s*/repadmin\b") {
                 $cmd = $cmd -replace "^(?i)\s*/repadmin\b", "repadmin"
             }
 
             if ($UseRemote) {
-                if (-not $sessions.ContainsKey($server)) {
+                $taskName = ("OneShot_AD_DNS_Repl_{0}" -f ($server -replace "[^A-Za-z0-9_-]", "_"))
-                    try {
+                $outFile = ("C:\Windows\Temp\repadmin-{0}.txt" -f $server)
-                        if ($Credential) {
+                $repadminCmd = $cmd
-                            $sessions[$server] = New-PSSession -ComputerName $server -Credential $Credential -ErrorAction Stop
+                $repadminCmd = [regex]::Replace($repadminCmd, "\s{2,}", " ").Trim()
-                        } else {
+                if ([string]::IsNullOrWhiteSpace($repadminCmd)) {
-                            $sessions[$server] = New-PSSession -ComputerName $server -ErrorAction Stop
-                        }
-                        & $Log "Replication session opened: $server"
-                    } catch {
-                        & $Log ("Replication session error on {0}: {1}" -f $server, $_.Exception.Message)
-                        continue
-                    }
-                }
-
-                $remoteCmd = $cmd.Replace("{server}", "").Trim()
-                $remoteCmd = [regex]::Replace($remoteCmd, "\s{2,}", " ")
-                if ($remoteCmd -match "(?i)\brepadmin\b" -and $remoteCmd -match "(?i)\bsyncall\b") {
-                    $remoteCmd = [regex]::Replace($remoteCmd, "(?i)\brepadmin\s+/syncall\s+\S+", "repadmin /syncall")
-                }
-                $remoteCmd = [regex]::Replace($remoteCmd, "(?i)\brepadmin\s+/syncall\b", "repadmin /syncall")
-                $remoteCmd = $remoteCmd.Replace("/AdeP", "/AedP")
-                $remoteCmd = [regex]::Replace($remoteCmd, "\s{2,}", " ").Trim()
-                if ([string]::IsNullOrWhiteSpace($remoteCmd)) {
                     & $Log "Replication skipped: empty command for $server."
                     continue
                 }
-                & $Log "Replication (remote): $server -> $remoteCmd"
+
+                & $Log "Replication (scheduled task): $SourceDc -> $server"
                 try {
-                    Invoke-Command -Session $sessions[$server] -ScriptBlock { param($c) & $env:ComSpec /c $c } -ArgumentList $remoteCmd |
+                    Invoke-Command -Session $session -ScriptBlock {
-                        ForEach-Object { & $Log $_ }
+                        param($DestDC, $TaskName, $OutFile, $RepadminCmd)
+
+                        $cmdLine = "cmd.exe /c $RepadminCmd > `"$OutFile`" 2>&1"
+                        schtasks /Create /F /TN $TaskName /RU SYSTEM /SC ONCE /ST 00:00 /TR $cmdLine | Out-Null
+                        schtasks /Run /TN $TaskName | Out-Null
+                        Start-Sleep 6
+
+                        $output = if (Test-Path $OutFile) { Get-Content $OutFile } else { "No output file found" }
+                        schtasks /Delete /F /TN $TaskName | Out-Null
+                        Remove-Item $OutFile -Force -ErrorAction SilentlyContinue
+
+                        $output
+                    } -ArgumentList $server, $taskName, $outFile, $repadminCmd | ForEach-Object { & $Log $_ }
                 } catch {
                     & $Log ("Replication error on {0}: {1}" -f $server, $_.Exception.Message)
                 }
@@ -333,7 +348,7 @@ function Invoke-Replication {
             & $env:ComSpec /c $cmd | ForEach-Object { & $Log $_ }
         }
     } finally {
-        foreach ($session in $sessions.Values) {
+        if ($session) {
             try { Remove-PSSession -Session $session } catch {}
         }
     }
@@ -626,7 +641,7 @@ $panel.Controls.Add($ipRefreshBtn)
 Style-ButtonSecondary $ipRefreshBtn
 $y += $rowHeight + $gap
 
-Add-Label "Primary DNS server" $xLabel $y $labelWidth $rowHeight
+Add-Label "Primary DNS server (source DC)" $xLabel $y $labelWidth $rowHeight
 $dnsServerBox = New-Object System.Windows.Forms.ComboBox
 $dnsServerBox.Location = [System.Drawing.Point]::new($xInput, $y)
 $dnsServerBox.Size = [System.Drawing.Size]::new(($inputWidth - ($buttonWidth + $buttonGap)), $rowHeight)
@@ -671,9 +686,9 @@ $panel.Controls.Add($primaryFromSelectedBtn)
 Style-ButtonSecondary $primaryFromSelectedBtn
 $y += 70 + $gap
 
-Add-Label "Replication command ({server} optional)" $xLabel $y $labelWidth $rowHeight
+Add-Label "Replication command ({dest} optional)" $xLabel $y $labelWidth $rowHeight
 $replicationCmdBox = Add-TextBox $xInput $y $inputWidth $rowHeight $false
-    $replicationCmdBox.Text = "repadmin /syncall /AedP"
+$replicationCmdBox.Text = "repadmin /syncall {dest} /AdeP"
 $y += $rowHeight + $gap
 
 Add-Label "Replication wait (seconds)" $xLabel $y $labelWidth $rowHeight
@@ -681,7 +696,7 @@ $replicationDelayBox = Add-TextBox $xInput $y $inputWidth $rowHeight $false
 $replicationDelayBox.Text = "30"
 $y += $rowHeight + $gap
 
-$replicationRemoteBox = Add-CheckBox "Run repadmin remotely (PowerShell)" $xInput $y $inputWidth $rowHeight
+$replicationRemoteBox = Add-CheckBox "Run replication via scheduled task on source DC" $xInput $y $inputWidth $rowHeight
 $replicationRemoteBox.Checked = $true
 $y += $rowHeight + $gap
 
@@ -1197,7 +1212,13 @@ $runBtn.Add_Click({
                     & $logAction "Replication credentials saved for this user."
                 }
             }
-            Invoke-Replication -Servers $replicationTargets -Command $replicationCmdBox.Text -UseRemote $replicationRemoteBox.Checked -Credential $replicationCredential -Log $logAction
+            Invoke-Replication `
+                -Servers $replicationTargets `
+                -Command $replicationCmdBox.Text `
+                -UseRemote $replicationRemoteBox.Checked `
+                -Credential $replicationCredential `
+                -SourceDc $dnsServer `
+                -Log $logAction
             if ($replicationDelaySeconds -gt 0) {
                 & $logAction "Waiting $replicationDelaySeconds seconds for replication."
                 Start-Sleep -Seconds $replicationDelaySeconds