SSL certificate binding breaks on EC2 AMI after running SysprepInstance.ps1

Packer
1

hello all, so most of people reading this will be familiar with Packer, I have a packer template shown below;

            "ami_name": "WIN2016-CUSTOM-{{user `build_version`}}",
            "instance_type": "t3.xlarge",
            "user_data_file": "userdata.txt",
            "associate_public_ip_address": true,
            "communicator": "winrm",
            "winrm_username": "Administrator",
            "winrm_port": 5986,
            "winrm_timeout": "15m",
            "winrm_use_ssl": true,
            "winrm_insecure": true

The content of user_data_file is shown below;

Remove-Item -Path WSMan:\Localhost\listener\listener* -Recurse
 
# Create self-signed cert for encrypted WinRM on port 5986
$Cert = New-SelfSignedCertificate -CertstoreLocation Cert:\LocalMachine\My -DnsName "packer-ami-builder"
New-Item -Path WSMan:\LocalHost\Listener -Transport HTTPS -Address * -CertificateThumbPrint $Cert.Thumbprint -Force
 
# Configure WinRM
cmd.exe /c winrm quickconfig -q
cmd.exe /c winrm set "winrm/config" '@{MaxTimeoutms="1800000"}'
cmd.exe /c winrm set "winrm/config/winrs" '@{MaxMemoryPerShellMB="1024"}'
cmd.exe /c winrm set "winrm/config/service" '@{AllowUnencrypted="false"}'
cmd.exe /c winrm set "winrm/config/client" '@{AllowUnencrypted="false"}'
cmd.exe /c winrm set "winrm/config/service/auth" '@{Basic="true"}'
cmd.exe /c winrm set "winrm/config/client/auth" '@{Basic="true"}'
cmd.exe /c winrm set "winrm/config/service/auth" '@{CredSSP="true"}'
cmd.exe /c winrm set "winrm/config/listener?Address=*+Transport=HTTPS" "@{Port=`"5986`";Hostname=`"packer-ami-builder`";CertificateThumbprint=`"$($Cert.Thumbprint)`"}"
cmd.exe /c netsh advfirewall firewall add rule name="WinRM-SSL (5986)" dir=in action=allow protocol=TCP localport=5986
cmd.exe /c net stop winrm
cmd.exe /c sc config winrm start= auto
cmd.exe /c net start winrm

At the end of the Packer template, I have provisioners for running PowerShell scripts, these are helper scripts located in EC2 by default;

"provisioners": [
        {
            "type": "powershell",
            "inline": [
                "C:\\ProgramData\\Amazon\\EC2-Windows\\Launch\\Scripts\\InitializeInstance.ps1 -Schedule",
                "C:\\ProgramData\\Amazon\\EC2-Windows\\Launch\\Scripts\\SysprepInstance.ps1 -NoShutdown"
            ]
        }
    ]

The problem is that if I use the SysprepInstance.ps1 script then it somehow mucks up the listener and certificate, I am yet to figure out how but it does. I have to run these 3 commands again to get the AMI configured for WinRM 5986 connectivity. Same commands that are run before have to be run again.

Remove-Item -Path WSMan:\Localhost\listener\listener* -Recurse
$Cert = New-SelfSignedCertificate -CertstoreLocation Cert:\LocalMachine\My -DnsName "packer-ami-builder"
New-Item -Path WSMan:\LocalHost\Listener -Transport HTTPS -Address * -CertificateThumbPrint $Cert.Thumbprint -Force

But if I leave out the SysprepInstance.ps1 script then the AMI image works fine. I have tried this on different occasions and tested my theory.

I understand that SysprepInstance.ps1 will generalize the AMI image & maybe that is the reason that I have to redo the commands to get WinRM 5986 working. Could be wrong though?

My question is, has anyone else come across this situation and if yes then what was the fix?

Even a point at to a GIT repo will help. Thanks.