exceptions

lib/snmpquery.py

@@ -1,11 +1,30 @@
 import logging
 from asyncsnmplib.client import Snmp, SnmpV1, SnmpV3
-from asyncsnmplib.exceptions import SnmpNoConnection, SnmpNoAuthParams
-from asyncsnmplib.mib.utils import on_result_base
+from asyncsnmplib.exceptions import SnmpException
+from asyncsnmplib.exceptions import SnmpNoAuthParams
+from asyncsnmplib.exceptions import SnmpNoConnection
+from asyncsnmplib.mib.utils import on_result
 from asyncsnmplib.v3.auth import AUTH_PROTO
 from asyncsnmplib.v3.encr import PRIV_PROTO
 from libprobe.asset import Asset
-from libprobe.exceptions import CheckException
+
+
+class InvalidCredentialsException(SnmpException):
+    message = 'Invalid SNMP v3 credentials.'
+
+
+class InvalidClientConfigException(SnmpException):
+    message = 'Invalid SNMP v3 client configuration.'
+
+
+class InvalidSnmpVersionException(SnmpException):
+    message = 'Invalid SNMP version.'
+
+
+class ParseResultException(SnmpException):
+    def __init__(self, message: str):
+        super().__init__(message)
+        self.message = message
 
 
 def snmpv3_credentials(asset_config: dict):
@@ -66,15 +85,13 @@ async def snmpquery(
         address = asset.name
 
     version = asset_config.get('version', '2c')
-    community = asset_config.get('community', 'public')
-    if not isinstance(community, str):
-        try:
-            community = community['secret']
-            assert isinstance(community, str)
-        except Exception:
-            raise CheckException('missing credentials')
 
     if version == '2c':
+        community = asset_config.get('community', 'public')
+        if isinstance(community, dict):
+            community = community.get('secret')
+        if not isinstance(community, str):
+            raise TypeError('SNMP community must be a string.')
         cl = Snmp(
             host=address,
             community=community,
@@ -83,49 +100,53 @@ async def snmpquery(
         try:
             cred = snmpv3_credentials(asset_config)
         except Exception as e:
-            logging.warning(f'invalid SNMP v3 credentials {asset}: {e}')
-            raise Exception('invalid SNMP v3 credentials')
+            logging.warning(f'invalid snmpv3 credentials {asset}: {e}')
+            raise InvalidCredentialsException
         try:
             cl = SnmpV3(
                 host=address,
                 **cred,
             )
         except Exception as e:
-            logging.warning(f'invalid SNMP v3 client config {asset}: {e}')
-            raise Exception('invalid SNMP v3 credentials')
+            logging.warning(f'invalid snmpv3 client config {asset}: {e}')
+            raise InvalidClientConfigException
     elif version == '1':
+        community = asset_config.get('community', 'public')
+        if isinstance(community, dict):
+            community = community.get('secret')
+        if not isinstance(community, str):
+            raise TypeError('SNMP community must be a string.')
         cl = SnmpV1(
             host=address,
             community=community,
         )
     else:
-        logging.warning(f'unsupported SNMP version {asset}: {version}')
-        raise CheckException('unsupported SNMP version')
+        logging.warning(f'unsupported snmp version {asset}: {version}')
+        raise InvalidSnmpVersionException
 
     try:
         await cl.connect()
     except SnmpNoConnection:
-        raise CheckException('failed to connect')
+        raise
     except SnmpNoAuthParams:
-        raise CheckException('failed to authenticate')
+        logging.warning('unable to connect: failed to set auth params')
+        raise
     else:
         results = {}
         try:
             for oid in queries:
                 result = await cl.walk(oid)
                 try:
-                    name, result = on_result_base(oid, result)
+                    name, result = on_result(oid, result)
                 except Exception as e:
                     msg = str(e) or type(e).__name__
-                    raise CheckException(
-                        f'parse result error: {msg}')
+                    raise ParseResultException(
+                        f'Failed to parse result. Exception: {msg}'
+                    )
                 else:
                     results[name] = result
-        except CheckException:
+        except Exception:
             raise
-        except Exception as e:
-            msg = str(e) or type(e).__name__
-            raise CheckException(msg)
         else:
             return results
     finally:

requirements.txt

@@ -1,2 +1,2 @@
-asyncsnmplib==0.1.10
+asyncsnmplib==0.1.11
 libprobe==0.2.33