Security Model

Threat model summary

The primary threat vectors considered are: a compromised worker VM accessing other tenants' data, a compromised edge server, and unauthorized access to the Proxmox management plane.

Control	What it protects
VLAN isolation (OpenWrt zones)	A compromised worker cannot initiate connections to the management network or DMZ. Worker blast radius is contained to VLAN 30.
No inbound port forwarding	The on-prem cluster has no externally-reachable ports. All connectivity goes via Netbird overlay.
Netbird overlay (WireGuard)	All traffic between edge and on-prem is encrypted in transit. Peers must present valid keys to join the mesh.
S3 IAM credentials per worker	Workers should use scoped credentials that allow writing only to their project prefix. Prevents cross-tenant data access via S3.
Workers write to S3 directly	Output data does not traverse the Internal VLAN — workers write to cloud storage directly using the S3 API over the internet egress path.
Proxmox management on VLAN 10	Proxmox UI is accessible only on the management VLAN. No public exposure. Accessible via Netbird for operators.
User data in cloud storage	Even if all on-prem nodes are lost, user simulation data is safe in Hetzner Object Storage.

Multi-tenancy note

At early stage, all users share the same Redis queue and S3 bucket (with prefix isolation). Before onboarding untrusted users, implement per-user S3 IAM policies and job queue namespacing to prevent one tenant from viewing another tenant's job status.