Tested with with Proxmox 9.1.2, Packer 1.14 and Packer Proxmox Plugin v1.2.3

Build VM Templates with Packer for Proxmox. The generated templates are meant to be used with cloud-init, they come without a User or root login. Only the Windows Server Template has a Administrator user by default (Password packer). It's ready for Ansible setup via winrm.

All templates are made for my personal environment and may need adjustments for yours!

OS	Status	Username / Password
Ubnuntu 24.04
Ubnuntu 22.04
Ubnuntu 20.04
Ubnuntu 18.04
Debian 13
Debian 12
Debian 11
AlmaLinux 10
AlmaLinux 9
Rocky 10
Rocky 9
Alpine 3.22
Alpine 3.21
Alpine 3.20
Windows Server 2025		Administrator / packer
Windows Server 2022		Administrator / packer
Windows Server 2019		Administrator / packer
Windows 11		Administrator / packer
Talos Linux 1.12		None
OPNsense 25.7		root / opnsense
VyOS rolling	⚠️ No GitHub Action (rolling release)	vyos / vyos

First initialize the proxmox packer plugin:

packer init config.pkr.hcl

The templates all use a generic source builder (generic.pkr.hcl) that's driven by variables. The OS specific settings are only variables and preseed files.

To build packer templates you need to set some variables via file (-var-file=my.pkrvars.hcl), cli (-var variablename=value), or environment (PKR_VAR_variablename=value):

• proxmox_host
• proxmox_user
• proxmox_password
• proxmox_token
• node
• vmid

Other interesting variables are:

• pool
• proxmox_insecure_tls
• disk_storage_pool
• iso_storage_pool
• cloud_init_storage_pool
• iso_download
• Windows:
  • windows_edition
  • windows_language / windows_input_language
  • winrm_username / winrm_password (Win11 alway creates a user, Win Server will use Administrator)

See variables.pkr.hcl for all varaibles.

To build a template (e.g. debian-13) run:

packer build -var-file="debian-13.pkrvars.hcl" .

You can run additional setup actions for windows by creating a file http/windows-scripts/custom/custom.ps1.

Example:

# debloat Windows 11: https://github.com/Raphire/Win11Debloat
& ([scriptblock]::Create((irm "https://debloat.raphi.re/"))) -RunDefaults -Sysprep -Silent

In some cases your proxmox server might be in a datacatenter. You can ssh to the proxmox server but the proxmox server can't connect to your build computer.

Set the following variables in your configuration.

• packer_http_interface to 127.0.0.1
• packer_http_port to 8000

Your Proxmox Server can be reached via ssh

Start this in a console on your build host and keep it open during build time.

# forward 127.0.0.1:8000 to the remote proxmox to 127.0.0.1:8000
ssh -N -R 127.0.0.1:8000:127.0.0.1:8000 root@proxmox

Your Proxmox Server can't be reached from the build computer via ssh

In this case you need a 2nd computer that can be reached from the proxmox computer and the build computer acting as relais.

On the proxmox host:

ssh -N -L 127.0.0.1:8000:127.0.0.1:8000 user@lighthouse

On the build computer:

ssh -N -R 127.0.0.1:8000:127.0.0.1:8000 user@lighthouse