Add SNMP device discovery API

2026-05-23 20:19:38 -06:00
parent 0cbc6b6ea8
commit a38438e7f1
7 changed files with 635 additions and 17 deletions
@@ -0,0 +1,113 @@
+from fastapi import APIRouter, Depends, HTTPException
+from sqlalchemy.orm import Session
+
+from app.api.credentials import SNMP_CREDENTIAL_TYPE
+from app.auth.dependencies import require_role
+from app.core.secrets import decrypt_secret
+from app.db.session import get_db
+from app.models import Credential, User
+from app.schemas.core import (
+    SnmpDiscoveredInterfaceRead,
+    SnmpDiscoveryItemRead,
+    SnmpDiscoveryRead,
+    SnmpDiscoveryRequest,
+)
+from app.services.snmp import DiscoveredSnmpDevice, SnmpCredential, SnmpDiscoveryError, discover_snmp_device
+
+router = APIRouter(prefix="/discovery", tags=["discovery"])
+
+
+@router.post("/snmp", response_model=SnmpDiscoveryRead)
+def discover_snmp(
+    payload: SnmpDiscoveryRequest,
+    _: User = Depends(require_role("admin")),
+    db: Session = Depends(get_db),
+) -> SnmpDiscoveryRead:
+    profile = db.get(Credential, payload.credential_profile_id)
+    if profile is None or profile.credential_type != SNMP_CREDENTIAL_TYPE:
+        raise HTTPException(status_code=404, detail="SNMP credential profile not found")
+
+    extra = dict(profile.extra or {})
+    version = str(extra.get("version") or "2c")
+    if version != "2c":
+        raise HTTPException(status_code=400, detail="SNMP discovery currently supports SNMPv2c profiles")
+
+    community = decrypt_secret(profile.encrypted_secret)
+    if not community:
+        raise HTTPException(status_code=400, detail="SNMP credential profile has no usable community string")
+
+    credential = SnmpCredential(
+        community=community,
+        port=int(extra.get("port") or 161),
+        timeout_seconds=int(extra.get("timeout_seconds") or 5),
+        retries=int(extra.get("retries") or 1),
+    )
+    try:
+        discovered = discover_snmp_device(payload.host, credential)
+    except SnmpDiscoveryError as exc:
+        raise HTTPException(status_code=502, detail="SNMP discovery failed") from exc
+
+    return _discovery_to_read(payload.credential_profile_id, discovered)
+
+
+def _discovery_to_read(credential_profile_id: int, discovered: DiscoveredSnmpDevice) -> SnmpDiscoveryRead:
+    interfaces = [
+        SnmpDiscoveredInterfaceRead(
+            index=interface.index,
+            name=interface.name,
+            description=interface.description,
+            admin_status=interface.admin_status,
+            oper_status=interface.oper_status,
+            speed_bps=interface.speed_bps,
+        )
+        for interface in discovered.interfaces
+    ]
+    return SnmpDiscoveryRead(
+        host=discovered.host,
+        credential_profile_id=credential_profile_id,
+        device_name=discovered.device_name,
+        description=discovered.description,
+        uptime_seconds=discovered.uptime_seconds,
+        interfaces=interfaces,
+        monitorable_items=_monitorable_items(discovered),
+    )
+
+
+def _monitorable_items(discovered: DiscoveredSnmpDevice) -> list[SnmpDiscoveryItemRead]:
+    items = [
+        SnmpDiscoveryItemRead(
+            item_id="device.uptime",
+            item_type="device_uptime",
+            group="Device Health",
+            label="Device uptime",
+            unit="seconds",
+        )
+    ]
+    for interface in discovered.interfaces:
+        group = f"Interface {interface.name}"
+        item_prefix = f"interface.{interface.index}"
+        items.extend(
+            [
+                SnmpDiscoveryItemRead(
+                    item_id=f"{item_prefix}.status",
+                    item_type="interface_status",
+                    group=group,
+                    label=f"{interface.name} status",
+                ),
+                SnmpDiscoveryItemRead(
+                    item_id=f"{item_prefix}.traffic",
+                    item_type="interface_traffic",
+                    group=group,
+                    label=f"{interface.name} traffic",
+                    unit="bps",
+                ),
+                SnmpDiscoveryItemRead(
+                    item_id=f"{item_prefix}.errors",
+                    item_type="interface_errors",
+                    group=group,
+                    label=f"{interface.name} errors and discards",
+                    unit="count",
+                ),
+            ]
+        )
+    return items