Omni + Proxmox Infrastructure Provider

This skill provides guidance for deploying and managing Talos Linux Kubernetes clusters via Sidero Omni with the Proxmox infrastructure provider.

Current Deployment

Component	Location	IP	Endpoint
Omni	Holly (VMID 101, Quantum)	192.168.10.20	https://omni.spaceships.work
Auth0 OIDC	Managed	—	Auth0 tenant
Proxmox Provider	Foxtrot LXC (CT 200, Matrix)	192.168.3.10	L2 adjacent to Talos VMs
Target Cluster	Matrix (Foxtrot/Golf/Hotel)	192.168.3.{5,6,7}	https://192.168.3.5:8006
Storage	CEPH RBD	—	vm_ssd pool

Architecture Overview

┌─────────────────────────────────────────────────────────────────────────────┐
│                              Tailnet                                         │
├─────────────────────────────────────────────────────────────────────────────┤
│                                                                              │
│   Quantum Cluster (192.168.10.0/24)       Matrix Cluster (192.168.3.0/24)   │
│   ┌───────────────────────────┐           ┌─────────────────────────────┐   │
│   │  Holly (VMID 101)         │           │  Foxtrot                    │   │
│   │  ┌─────────────────────┐  │           │  ┌───────────────────────┐  │   │
│   │  │  Docker Stack       │  │           │  │  LXC CT 200           │  │   │
│   │  │  ├─ omni-tailscale  │  │◄─────────►│  │  ├─ worker-tailscale  │  │   │
│   │  │  └─ omni            │  │  Tailnet  │  │  └─ proxmox-provider  │  │   │
│   │  └─────────────────────┘  │           │  └───────────────────────┘  │   │
│   │           │               │           │             │               │   │
│   │  LAN: 192.168.10.20       │           │    LAN: 192.168.3.10        │   │
│   └───────────────────────────┘           │             │               │   │
│              │                            │             ▼ L2 Adjacent   │   │
│              ▼                            │  ┌───────────────────────┐  │   │
│   ┌───────────────────────────┐           │  │  Proxmox API          │  │   │
│   │  Auth0 (External)         │           │  │  (Foxtrot/Golf/Hotel) │  │   │
│   │  OIDC Provider            │           │  └───────────────────────┘  │   │
│   └───────────────────────────┘           │             │               │   │
│                                           │             ▼               │   │
│   ┌───────────────────────────┐           │  ┌───────────────────────┐  │   │
│   │  Browser                  │──────────►│  │  Talos VMs            │  │   │
│   │  (Admin UI via Tailscale) │           │  │  (CEPH vm_ssd)        │  │   │
│   └───────────────────────────┘           │  └───────────────────────┘  │   │
│                                           └─────────────────────────────┘   │
└─────────────────────────────────────────────────────────────────────────────┘

Key architectural decisions:

Decision	Rationale
Omni on Holly (Quantum)	Separation of management plane from workload plane
Provider on Foxtrot LXC	L2 adjacency required for SideroLink registration
Auth0 for OIDC	Managed service, simpler than self-hosted tsidp
CEPH storage	Distributed storage across Matrix nodes

L2 Adjacency Requirement:

The Proxmox provider must be network-adjacent to Talos VMs for SideroLink machine registration. When a Talos VM boots, it broadcasts on the local network to find the Omni control plane. The provider on Foxtrot LXC (192.168.3.10) shares L2 with Talos VMs on the Matrix cluster (192.168.3.x).

Split-Horizon DNS:

Talos VMs resolve omni.spaceships.work via Unifi local DNS to 192.168.10.20 (Holly's LAN IP). Static routing between 192.168.3.0/24 and 192.168.10.0/24 enables cross-subnet SideroLink registration.

Provider Configuration

The Proxmox provider runs as Docker containers inside the omni-provider LXC (CT 200) on Foxtrot.

File locations:

File	Purpose
proxmox-provider/compose.yml	Docker Compose for provider + Tailscale sidecar
proxmox-provider/config.yaml	Proxmox API credentials (gitignored)
proxmox-provider/.env	Environment variables (gitignored)

Setup:

# Copy example files
cp proxmox-provider/config.yaml.example proxmox-provider/config.yaml
cp proxmox-provider/.env.example proxmox-provider/.env

# Edit with actual credentials
vim proxmox-provider/config.yaml  # Proxmox API token
vim proxmox-provider/.env         # Tailscale key, Omni service account

# Deploy
cd proxmox-provider
docker compose up -d

Provider Config (config.yaml)

proxmox:
  url: "https://192.168.3.5:8006/api2/json"
  tokenID: "terraform@pam!automation"
  tokenSecret: "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
  insecureSkipVerify: true  # Self-signed Proxmox certs

For Proxmox API token setup, see references/proxmox-permissions.md.

MachineClass Structure

MachineClasses define VM specifications for auto-provisioning. Apply via omnictl.

metadata:
  namespace: default
  type: MachineClasses.omni.sidero.dev
  id: matrix-worker
spec:
  autoprovision:
    providerid: matrix-cluster
    providerdata: |
      cores: 4
      sockets: 1
      memory: 16384
      disk_size: 100
      network_bridge: vmbr0
      storage_selector: name == "vm_ssd"
      node: foxtrot  # Pin to specific node (requires PR #38)

Provider Data Fields:

Source: PR #36 (merged Dec 30, 2025)

Category	Fields
Compute	cores, sockets, memory, cpu_type, machine_type, numa, hugepages, balloon
Storage	disk_size, storage_selector, disk_ssd, disk_discard, disk_iothread, disk_cache, disk_aio, additional_disks
Network	network_bridge, vlan, additional_nics
PCI	pci_devices (requires Proxmox resource mappings)
Placement	node (PR #38)

Compute Fields

Field	Type	Default	Description
cores	int	required	CPU cores per socket
sockets	int	1	Number of CPU sockets
memory	int	required	RAM in MB
cpu_type	string	x86-64-v2-AES	CPU type. Use host for passthrough
machine_type	string	i440fx	VM machine type. Use q35 for PCIe passthrough
numa	bool	false	Enable NUMA topology
hugepages	string	-	Hugepages size: 2, 1024, or any
balloon	bool	true	Enable memory ballooning. Disable for GPU/HPC

Storage Fields

Field	Type	Default	Description
disk_size	int	required	Primary disk size in GB
storage_selector	string	required	CEL expression for storage pool
disk_ssd	bool	false	Enable SSD emulation
disk_discard	bool	false	Enable TRIM/discard support
disk_iothread	bool	false	Enable dedicated IO thread
disk_cache	string	-	Cache mode: none, writeback, writethrough, directsync, unsafe
disk_aio	string	-	AIO mode: native, io_uring, threads

Additional disks:

additional_disks:
  - disk_size: 500
    storage_selector: name == "nvme-pool"
    disk_ssd: true
    disk_iothread: true
  - disk_size: 1000
    storage_selector: name == "hdd-archive"
    disk_cache: writeback

Network Fields

Field	Type	Default	Description
network_bridge	string	vmbr0	Primary network bridge
vlan	int	0	VLAN tag (0 = untagged)

Additional NICs:

additional_nics:
  - bridge: vmbr1
    firewall: false
  - bridge: vmbr2
    vlan: 20

PCI Passthrough

Requires Proxmox Resource Mappings configured.

pci_devices:
  - mapping: nvidia-rtx-4090
    pcie: true

Field	Type	Description
mapping	string	Proxmox resource mapping name
pcie	bool	Use PCIe (requires machine_type: q35)

Placement Fields

Field	Type	Default	Description
node	string	-	Pin VM to specific Proxmox node

CEL Storage Selectors

The provider uses CEL (Common Expression Language) to select storage pools.

Available fields:

Field	Type	Description
name	string	Storage pool name

Warning: The type field is NOT usable — type is a reserved CEL keyword. Use name for all storage selection.

Matrix cluster storage:

# CEPH RBD pool (recommended)
name == "vm_ssd"

# Container storage
name == "vm_containers"

For complete CEL syntax, see references/cel-storage-selectors.md.

omnictl CLI

Service account key (automation):

omnictl --omni-url https://omni.spaceships.work \
        --service-account-key $OMNICTL_SERVICE_ACCOUNT_KEY \
        get clusters

OIDC browser flow (interactive):

# Any command triggers browser auth if not authenticated
omnictl get clusters

Common operations:

# List machine classes
omnictl get machineclasses

# Apply machine class
omnictl apply -f machine-classes/matrix-worker.yaml

# Sync cluster template
omnictl cluster template sync -f clusters/talos-prod-01.yaml

# Check cluster status
omnictl cluster status talos-prod-01

# Get machines
omnictl get machines --cluster talos-prod-01

Cluster Templates

Multi-document YAML defining cluster, control plane, and workers:

kind: Cluster
name: talos-prod-01
kubernetes:
  version: v1.34.3
talos:
  version: v1.11.6
patches:
  - name: disable-default-cni
    inline:
      cluster:
        network:
          cni:
            name: none    # Required for Cilium
        proxy:
          disabled: true  # Cilium replaces kube-proxy
---
kind: ControlPlane
machineClass:
  name: matrix-control-plane
  size: 3
systemExtensions:
  - siderolabs/qemu-guest-agent
  - siderolabs/iscsi-tools
---
kind: Workers
machineClass:
  name: matrix-worker
  size: 2
systemExtensions:
  - siderolabs/qemu-guest-agent
  - siderolabs/iscsi-tools

See clusters/talos-prod-01.yaml for the full production template.

Troubleshooting

Provider not registering

# Check provider logs (on Foxtrot LXC)
ssh omni-provider docker logs -f proxmox-provider

# Verify Tailscale connectivity
ssh omni-provider docker exec worker-tailscale tailscale status

Machines stuck in provisioning

# Check Proxmox for VM creation
pvesh get /nodes/foxtrot/qemu --output-format json | jq '.[] | {vmid, name, status}'

# Check provider logs for errors
ssh omni-provider docker logs --tail=50 proxmox-provider | grep -i error

Storage selector not matching

# List available storage pools
pvesh get /storage --output-format json | jq '.[].storage'

# Test CEL expression (provider logs show evaluation)
# Look for: "no storage pools matched selector"

For more troubleshooting, see references/troubleshooting.md.

Key Constraints

Networking:

• Provider MUST be L2 adjacent to Talos VMs (Foxtrot LXC on 192.168.3.x)
• Omni on Holly (192.168.10.20) reachable via static route
• Split-horizon DNS: omni.spaceships.work → 192.168.10.20 (LAN) or Tailscale IP (external)

Provider limitations:

• CEL type keyword reserved — use name only for storage selectors
• Hostname conflict bug: Upstream provider injects hostname config that conflicts with Omni. Requires local patched build (:local-fix tag). See docs/TROUBLESHOOTING.md.

Omni template limitations:

• ControlPlane pinning not possible: Omni requires exactly 1 kind: ControlPlane section per cluster template. Cannot use multiple pinned machine classes for CPs.
• Workers CAN be pinned via multiple kind: Workers sections with different machine classes.
• See docs/TROUBLESHOOTING.md → "Control Plane Node Distribution Cannot Be Pinned".

Upstream PRs (merged):

• PR #36 — Advanced VM options (multi-disk, PCI passthrough, etc.)
• PR #38 — Node pinning support

Storage:

• Use CEPH vm_ssd pool for production VMs
• CEPH provides HA across Matrix nodes
• ~12TB usable capacity (replication factor 3)

Reference Files

• references/cel-storage-selectors.md — CEL syntax and patterns
• references/proxmox-permissions.md — API token setup
• references/omnictl-auth.md — Authentication methods
• references/troubleshooting.md — Common issues

Example Files

• examples/machineclass-ceph.yaml — MachineClass with CEPH storage
• examples/machineclass-local.yaml — MachineClass with local LVM
• examples/cluster-template.yaml — Complete cluster template
• examples/proxmox-gpu-worker.yaml — GPU worker MachineClass
• examples/proxmox-storage-node.yaml — Storage node MachineClass
• examples/proxmox-worker-multi-net.yaml — Multi-network worker MachineClass