fix(api): add SNMP fields to device create/read/update schemas and service

DeviceCreate now accepts device_type, snmp_port, snmp_version,
snmp_profile_id, credential_profile_id, and community string.
Username/password are optional (not needed for SNMP devices).
A model validator ensures at least one credential method is provided.

DeviceResponse and DeviceUpdate include the same SNMP fields so
list/detail endpoints return them and users can modify them.

The create_device service skips TCP probe for SNMP devices (UDP),
encrypts inline community strings via Transit, and sets all SNMP
columns on the Device ORM object.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/app/schemas/device.py

@@ -4,7 +4,7 @@ import uuid
 from datetime import datetime
 from typing import Optional
 
-from pydantic import BaseModel, field_validator
+from pydantic import BaseModel, field_validator, model_validator
 
 
 # ---------------------------------------------------------------------------
@@ -13,14 +13,49 @@ from pydantic import BaseModel, field_validator
 
 
 class DeviceCreate(BaseModel):
-    """Schema for creating a new device."""
+    """Schema for creating a new device (RouterOS or SNMP)."""
 
     hostname: str
     ip_address: str
     api_port: int = 8728
     api_ssl_port: int = 8729
-    username: str
-    password: str
+    # RouterOS credentials — optional for SNMP devices
+    username: Optional[str] = None
+    password: Optional[str] = None
+    # SNMP / device-type fields
+    device_type: str = "routeros"
+    snmp_port: int = 161
+    snmp_version: Optional[str] = None  # "v1", "v2c", "v3"
+    snmp_profile_id: Optional[str] = None
+    credential_profile_id: Optional[str] = None
+    community: Optional[str] = None  # inline v2c community string
+
+    @field_validator("device_type")
+    @classmethod
+    def validate_device_type(cls, v: str) -> str:
+        if v not in ("routeros", "snmp"):
+            raise ValueError("device_type must be 'routeros' or 'snmp'")
+        return v
+
+    @field_validator("snmp_version")
+    @classmethod
+    def validate_snmp_version(cls, v: Optional[str]) -> Optional[str]:
+        if v is not None and v not in ("v1", "v2c", "v3"):
+            raise ValueError("snmp_version must be 'v1', 'v2c', or 'v3'")
+        return v
+
+    @model_validator(mode="after")
+    def validate_credentials(self) -> "DeviceCreate":
+        """Ensure some form of authentication is provided."""
+        has_user_pass = self.username is not None and self.password is not None
+        has_profile = self.credential_profile_id is not None
+        has_community = self.community is not None
+        if not has_user_pass and not has_profile and not has_community:
+            raise ValueError(
+                "Credentials required: provide (username + password), "
+                "credential_profile_id, or community string"
+            )
+        return self
 
 
 class DeviceUpdate(BaseModel):
@@ -36,6 +71,10 @@ class DeviceUpdate(BaseModel):
     longitude: Optional[float] = None
     tls_mode: Optional[str] = None
     credential_profile_id: Optional[uuid.UUID] = None
+    # SNMP fields
+    snmp_port: Optional[int] = None
+    snmp_version: Optional[str] = None
+    snmp_profile_id: Optional[uuid.UUID] = None
 
     @field_validator("tls_mode")
     @classmethod
@@ -48,6 +87,13 @@ class DeviceUpdate(BaseModel):
             raise ValueError(f"tls_mode must be one of: {', '.join(sorted(allowed))}")
         return v
 
+    @field_validator("snmp_version")
+    @classmethod
+    def validate_snmp_version(cls, v: Optional[str]) -> Optional[str]:
+        if v is not None and v not in ("v1", "v2c", "v3"):
+            raise ValueError("snmp_version must be 'v1', 'v2c', or 'v3'")
+        return v
+
 
 class DeviceTagRef(BaseModel):
     """Minimal tag info embedded in device responses."""
@@ -87,6 +133,12 @@ class DeviceResponse(BaseModel):
     longitude: Optional[float] = None
     status: str
     tls_mode: str = "auto"
+    # SNMP / device-type fields
+    device_type: str = "routeros"
+    snmp_port: Optional[int] = None
+    snmp_version: Optional[str] = None
+    snmp_profile_id: Optional[uuid.UUID] = None
+    credential_profile_id: Optional[uuid.UUID] = None
     tags: list[DeviceTagRef] = []
     groups: list[DeviceGroupRef] = []
     site_id: Optional[uuid.UUID] = None

backend/app/services/device.py

@@ -111,6 +111,11 @@ def _build_device_response(device: Device) -> DeviceResponse:
         longitude=device.longitude,
         status=device.status,
         tls_mode=device.tls_mode,
+        device_type=device.device_type,
+        snmp_port=device.snmp_port,
+        snmp_version=device.snmp_version,
+        snmp_profile_id=device.snmp_profile_id,
+        credential_profile_id=device.credential_profile_id,
         tags=tags,
         groups=groups,
         site_id=device.site_id,
@@ -144,13 +149,16 @@ async def create_device(
     encryption_key: bytes,
 ) -> DeviceResponse:
     """
-    Create a new device.
+    Create a new device (RouterOS or SNMP).
 
-    - Validates TCP connectivity (api_port or api_ssl_port must be reachable).
-    - Encrypts credentials before storage.
-    - Status set to "unknown" until the Go poller runs a full auth check (Phase 2).
+    - RouterOS: validates TCP connectivity, encrypts username/password.
+    - SNMP: skips TCP probe (UDP), encrypts community string if provided inline.
+    - Status set to "unknown" until the poller runs a full check.
     """
-    # Test connectivity before accepting the device
+    is_snmp = data.device_type == "snmp"
+
+    # TCP reachability check — only for RouterOS devices (SNMP uses UDP)
+    if not is_snmp:
         api_reachable = await _tcp_reachable(data.ip_address, data.api_port)
         ssl_reachable = await _tcp_reachable(data.ip_address, data.api_ssl_port)
 
@@ -166,17 +174,36 @@ async def create_device(
                 ),
             )
 
-    # Encrypt credentials via OpenBao Transit (new writes go through Transit)
+    # Encrypt credentials via OpenBao Transit
+    transit_ciphertext = None
+    if data.username is not None and data.password is not None:
+        # RouterOS username/password or SNMP v3 with user/pass
         credentials_json = json.dumps({"username": data.username, "password": data.password})
         transit_ciphertext = await encrypt_credentials_transit(credentials_json, str(tenant_id))
+    elif data.community is not None:
+        # Inline SNMP v2c community string — store as encrypted credential
+        credentials_json = json.dumps({"community": data.community, "type": "snmp_v2c"})
+        transit_ciphertext = await encrypt_credentials_transit(credentials_json, str(tenant_id))
+
+    # Resolve credential_profile_id and snmp_profile_id (string -> UUID)
+    credential_profile_uuid = (
+        uuid.UUID(data.credential_profile_id) if data.credential_profile_id else None
+    )
+    snmp_profile_uuid = uuid.UUID(data.snmp_profile_id) if data.snmp_profile_id else None
 
     device = Device(
         tenant_id=tenant_id,
         hostname=data.hostname,
         ip_address=data.ip_address,
+        device_type=data.device_type,
         api_port=data.api_port,
         api_ssl_port=data.api_ssl_port,
         encrypted_credentials_transit=transit_ciphertext,
+        # SNMP fields
+        snmp_port=data.snmp_port if is_snmp else 161,
+        snmp_version=data.snmp_version if is_snmp else None,
+        snmp_profile_id=snmp_profile_uuid,
+        credential_profile_id=credential_profile_uuid,
         status="unknown",
     )
     db.add(device)
@@ -321,6 +348,13 @@ async def update_device(
         device.longitude = data.longitude
     if data.tls_mode is not None:
         device.tls_mode = data.tls_mode
+    # SNMP fields
+    if data.snmp_port is not None:
+        device.snmp_port = data.snmp_port
+    if data.snmp_version is not None:
+        device.snmp_version = data.snmp_version
+    if data.snmp_profile_id is not None:
+        device.snmp_profile_id = data.snmp_profile_id
 
     # Assign credential profile if provided
     if data.credential_profile_id is not None: