# Infrahub Schema for EVPN-VXLAN Fabric

This directory contains the Infrahub schema definitions for modeling an EVPN-VXLAN fabric. The schema is designed to represent the [arista-evpn-vxlan-clab](https://gitea.arnodo.fr/Damien/arista-evpn-vxlan-clab) topology.

## Schema Files

| File | Description |
|------|-------------|
| `base.yml` | Core infrastructure: Device, Interface types, IP Address, Platform, Site |
| `vlan_vxlan.yml` | VLAN, VNI, VTEP, EVPN Instance |
| `vrf.yml` | VRF, Route Target, VRF assignments |
| `bgp.yml` | Autonomous System, BGP Config, Peer Groups, Sessions |
| `mlag.yml` | MLAG Domain, Peer Config, MLAG Interfaces |
| `extensions.yml` | Fabric, Underlay Links, Host Connections |

## Entity Relationship Diagram

```
┌─────────────────────────────────────────────────────────────────────────────┐
│                              FABRIC TOPOLOGY                                │
└─────────────────────────────────────────────────────────────────────────────┘

                              ┌──────────────┐
                              │  InfraFabric │
                              └──────┬───────┘
                                     │
              ┌──────────────────────┼──────────────────────┐
              │                      │                      │
              ▼                      ▼                      ▼
       ┌────────────┐        ┌─────────────┐        ┌────────────┐
       │ LocationSite│       │ InfraDevice │        │InfraAutono-│
       └────────────┘        │  (spine/    │        │mousSystem  │
                             │   leaf)     │        └─────┬──────┘
                             └──────┬──────┘              │
                                    │                     │
       ┌────────────────────────────┼─────────────────────┤
       │                            │                     │
       ▼                            ▼                     ▼
┌──────────────┐            ┌──────────────┐      ┌──────────────┐
│InfraInterface│            │InfraMlagDomain│     │InfraBGPRouter│
│  (generic)   │            │  (leaf pair) │     │   Config     │
└──────┬───────┘            └──────────────┘      └──────┬───────┘
       │                                                  │
       │   ┌─────────────────────────┬───────────────────┤
       │   │                         │                   │
       ▼   ▼                         ▼                   ▼
┌──────────────┐            ┌──────────────┐      ┌──────────────┐
│InterfaceTypes│            │InfraBGPPeer- │      │ InfraBGP-    │
│ - Ethernet   │            │    Group     │      │  Session     │
│ - Loopback   │            │ (underlay,   │      │ (neighbors)  │
│ - Vlan       │            │  evpn)       │      └──────────────┘
│ - Lag        │            └──────────────┘
│ - Vxlan      │
└──────┬───────┘
       │
       ▼
┌──────────────┐      ┌──────────────┐      ┌──────────────┐
│InfraIPAddress│◄────►│  InfraVLAN   │◄────►│   InfraVNI   │
└──────────────┘      └──────────────┘      └──────────────┘
                             │
                             ▼
                      ┌──────────────┐
                      │  InfraVTEP   │
                      └──────────────┘
```

## Reference Topology Mapping

The schema models this topology from `arista-evpn-vxlan-clab`:

| Physical | Infrahub Model |
|----------|----------------|
| spine1, spine2 | InfraDevice (role: spine) |
| leaf1-8 | InfraDevice (role: leaf) |
| AS 65000 | InfraAutonomousSystem (spines) |
| AS 65001-65004 | InfraAutonomousSystem (leaf pairs) |
| VLAN 40, 34, 78 | InfraVLAN + InfraVNI |
| VLAN 4090, 4091 | InfraVLAN (vlan_type: mlag_peer/mlag_ibgp) |
| leaf1+leaf2 pair | InfraMlagDomain |
| Port-Channel999 | InfraInterfaceLag (peer-link) |
| Port-Channel1 | InfraMlagInterface (host-facing) |
| Ethernet1-8 | InfraInterfaceEthernet |
| Loopback0, Loopback1 | InfraInterfaceLoopback |
| Vxlan1 | InfraInterfaceVxlan |
| peer groups | InfraBGPPeerGroup |

## Usage

### Loading the Schema

```bash
# From the fabric-orchestrator root directory
infrahubctl schema load schemas/
```

### Validation

```bash
infrahubctl schema check schemas/
```

## Key Design Decisions

1. **Generic Interface**: All interface types inherit from `InfraInterface` generic for polymorphic queries
2. **MLAG as Domain**: MLAG is modeled as a domain containing exactly 2 devices, with per-device config
3. **BGP Hierarchy**: BGPRouterConfig → PeerGroups → Sessions allows template-based configuration
4. **VTEP Independence**: VTEP is separate from Device to support shared VTEP scenarios
5. **EVPN Instance per VLAN**: Allows device-specific RD/RT while referencing common VLAN/VNI

## Related Issues

- Parent issue: [#41 - Define Infrahub Schema for EVPN-VXLAN Fabric](https://gitea.arnodo.fr/Damien/fabric-orchestrator/issues/41)
- Depends on: Schema being loaded before transforms (#30, #31, #32, #33)