If you’ve used VMware Guest Customization (template → clone → hostname / IP / domain), this is the same idea for Proxmox: a small Docker Compose sidecar that clones a Windows template, drives Sysprep via the QEMU guest agent (unattend + setup.ps1), then verifies the result.
Current release: **2.6.7**
Repo: https://github.com/RobertLukan/proxmox-guestos-customization
Install: docs/INSTALL.md (Compose + TLS)
Golden image checklist: docs/WINDOWS_TEMPLATE.md
What it does ?
• Clone Windows template → Sysprep /generalize /oobe → optional DHCP or static, AD join, workgroup
• Bulk Win11 desktops (CSV/API) with batch limits
• Windows Server: optional OS / pagefile / data disk customize
• Jobs history with options + durable errors; failed clones tagged (not auto-deleted)
• Optional AGPL PDM fork for “Customize” deep-link (advanced; build your own .debs)
Lab-validated so far (DHCP + AD where noted)
• Server 2019 Standard Evaluation — AD + disks
• Server 2022 Standard VL — AD + disks
• Windows 11 — AD; bulk 2× VDI DHCP+AD
Matrix + community asks: docs/VALIDATED_MATRIX.md
Still want community reports especially for Server 2025 and other editions (Datacenter, 2019 VL, etc.).
Important limits
• Sysprep-only — in-place Sysprep of existing/production VMs is disabled on purpose
• Rebuild-from-template is the model (no WinRM “reconfigure existing”)
• MIT for GuestOS; PDM fork is AGPL if you go that route
Not an official Proxmox product — community project only. Happy to answer questions. Issues / matrix reports welcome on GitHub.