feat: add netplan configuration models and backend API for applying netplan

backend/src/Models/netplan.py

@@ -0,0 +1,36 @@
+from pydantic import BaseModel, Field
+from typing import List, Dict, Optional
+
+
+class Nameservers(BaseModel):
+    addresses: List[str] = Field(default_factory=list)
+    search: List[str] = Field(default_factory=list)
+
+
+class EthernetConfig(BaseModel):
+    dhcp4: Optional[bool] = None
+    dhcp6: Optional[bool] = None
+    addresses: Optional[List[str]] = None
+    gateway4: Optional[str] = None
+    gateway6: Optional[str] = None
+    nameservers: Optional[Nameservers] = None
+    optional: Optional[bool] = None
+
+
+class BridgeConfig(BaseModel):
+    interfaces: List[str] = Field(default_factory=list)  # ["eth1", "eth2"]
+    dhcp4: Optional[bool] = None
+    dhcp6: Optional[bool] = None
+    addresses: Optional[List[str]] = None
+    gateway4: Optional[str] = None
+    gateway6: Optional[str] = None
+    nameservers: Optional[Nameservers] = None
+    parameters: Optional[dict] = None  # allows spanning-tree, port-priority, forward-delay, etc.
+    optional: Optional[bool] = None
+
+
+class NetworkConfig(BaseModel):
+    version: int = 2
+    renderer: Optional[str] = "networkd"
+    ethernets: Dict[str, EthernetConfig] = Field(default_factory=dict)
+    bridges: Dict[str, BridgeConfig] = Field(default_factory=dict)