catch snmp library error

inventory_provider/snmp.py

@@ -6,6 +6,7 @@ import struct
 from pysnmp.hlapi import nextCmd, SnmpEngine, CommunityData, \
     UdpTransportTarget, ContextData, ObjectType, ObjectIdentity
 from pysnmp.smi import builder, compiler
+from pysnmp.error import PySnmpError
 # from pysnmp.smi import view, rfc1902
 
 
@@ -84,46 +85,51 @@ def walk(agent_hostname, community, base_oid):  # pragma: no cover
 
     logger.debug("walking %s: %s" % (agent_hostname, base_oid))
 
-    for (engineErrorIndication,
-         pduErrorIndication,
-         errorIndex,
-         varBinds) in nextCmd(
-            SnmpEngine(),
-            CommunityData(community),
-            UdpTransportTarget((agent_hostname, 161)),
-            ContextData(),
-            ObjectType(ObjectIdentity(base_oid)),
-            lexicographicMode=False,
-            lookupNames=True,
-            lookupValues=True):
-
-        # cf. http://snmplabs.com/
-        #       pysnmp/examples/hlapi/asyncore/sync/contents.html
-        if engineErrorIndication:
-            raise SNMPWalkError(
-                f'snmp response engine error indication: '
-                f'{str(engineErrorIndication)} - {agent_hostname}')
-        if pduErrorIndication:
-            raise SNMPWalkError(
-                'snmp response pdu error %r at %r' % (
-                    pduErrorIndication,
-                    errorIndex and varBinds[int(errorIndex) - 1][0] or '?'))
-        if errorIndex != 0:
-            raise SNMPWalkError(
-                'sanity failure: errorIndex != 0, '
-                'but no error indication')
-
-        # varBinds = [
-        #     rfc1902.ObjectType(rfc1902.ObjectIdentity(x[0]),x[1])
-        #         .resolveWithMib(mibViewController)
-        #     for x in varBinds]
-        for oid, val in varBinds:
-            result = {
-                "oid": _canonify_oid(oid),
-                "value": _cast_snmp_value(val)
-            }
-            logger.debug(result)
-            yield result
+    try:
+        for (engineErrorIndication,
+             pduErrorIndication,
+             errorIndex,
+             varBinds) in nextCmd(
+                SnmpEngine(),
+                CommunityData(community),
+                UdpTransportTarget((agent_hostname, 161)),
+                ContextData(),
+                ObjectType(ObjectIdentity(base_oid)),
+                lexicographicMode=False,
+                lookupNames=True,
+                lookupValues=True):
+
+            # cf. http://snmplabs.com/
+            #       pysnmp/examples/hlapi/asyncore/sync/contents.html
+            if engineErrorIndication:
+                raise SNMPWalkError(
+                    f'snmp response engine error indication: '
+                    f'{str(engineErrorIndication)} - {agent_hostname}')
+            if pduErrorIndication:
+                raise SNMPWalkError(
+                    'snmp response pdu error %r at %r' % (
+                        pduErrorIndication,
+                        errorIndex and varBinds[int(errorIndex) - 1][0] or '?'))
+            if errorIndex != 0:
+                raise SNMPWalkError(
+                    'sanity failure: errorIndex != 0, '
+                    'but no error indication')
+
+            # varBinds = [
+            #     rfc1902.ObjectType(rfc1902.ObjectIdentity(x[0]),x[1])
+            #         .resolveWithMib(mibViewController)
+            #     for x in varBinds]
+            for oid, val in varBinds:
+                result = {
+                    "oid": _canonify_oid(oid),
+                    "value": _cast_snmp_value(val)
+                }
+                logger.debug(result)
+                yield result
+
+    except PySnmpError as e:
+        raise SNMPWalkError(
+            f'snmp error communicating with {agent_hostname}: {e}')
 
 
 def get_router_snmp_indexes(hostname, community):