Projects using PySNMP

TwistedSNMP

Zenoss

Relevant projects

SNMPy YAPSNMP LibSMI Scotty software

import types
from pysnmp import msession

class snmpbulk (msession.multisession):
    """Fetch a bulk of variables from remote SNMP process
    """
    def __init__ (self):
        """Explicitly call superclass's constructor as it gets
           overloaded by this class constructor and pass a few
           arguments alone.
        """
        msession.multisession.__init__ (self)

    def run (self, agent, community, objids):
        """Issue a bulk of SNMP GET requests and wait for replies to
           come. The objids argument should be a list of strings where
           each string represents a Object ID in dotted numbers notation
           (e.g. ['.1.3.6.1.4.1.307.3.2.1.1.1.4.1']).
        """   
        # Convert string type Object ID's into numeric representation
        numeric_objids = map (self.str2nums, objids)

        # BER encode SNMP Object ID's to query
        encoded_objids = map (self.encode_oid, numeric_objids)

        # Since we are going to _query_ SNMP agent for Object ID's
        # associated value, there will be no variable values passed to
        # SNMP agent.
        encoded_values = []

        # Walk over supplied Object ID's
        for encoded_objid in encoded_objids:
            # Build and submit complete SNMP message of type 'GETREQUEST',
            # pass it a list of BER encoded Object ID's (only one as we are going to
            # query a number of Object ID's in bulk) to query and an empty list
            # of values associated with these Object ID's (empty list as there is
            # no point to pass any variables values along the SNMP GET request).
            self.submit_request (agent, community, 'GETREQUEST', [ encoded_objid ], encoded_values)

        # At this point we get a number of submitted SNMP GET requests. Now,
        # send them out all at once.
        self.dispatch ()

        # At this point we get all the replies from SNMP agents we expected (some
        # may time out). Retrieve a list of tuples (encoded_objid, encoded_value)
        encoded_pairs = self.retrieve ()

        # Parse out encoded_objid's
        encoded_objids =  reduce (lambda x, y: x + y, map (lambda x: x[0], encoded_pairs))

        # Parse out encoded_vals
        encoded_values =  reduce (lambda x, y: x + y, map (lambda x: x[1], encoded_pairs))

        # Decode BER encoded Object ID.
        objids = map (self.decode_value, encoded_objids)

        # Decode BER encoded values associated with Object ID's.
        values = map (self.decode_value, encoded_values)
        
        # Return a tuble of two lists holding Object ID's and associated
        # values extracted from SNMP agent replies.
        return (objids, values)

# Run the module if it's invoked for execution
if __name__ == '__main__':
    # The sys module is required for exit() function
    import sys

    # Make sure we have got enough args
    if len (sys.argv) < 4:
        # Report a usage error
        print 'Usage: %s   ' % sys.argv[0]

        # Incomplete command line arguments, exiting
        sys.exit (1)

    # Create an instance of snmpget class
    instance = snmpbulk ()

    # Run snmpbulk against passed Object ID's and expect it to return a list
    # of Object ID's and corresponding values as reported by SNMP agent
    (objids, values) = instance.run (sys.argv[1], sys.argv[2], sys.argv[3:])

    # Convert two lists into a list of tuples for easier printing
    results = map (None, objids, values)

    # Convert two lists into a list of tuples for easier printing
    results = map (None, objids, values)

    # Just print them out
    for (objid, value) in results:
        response =  response + objid + ' ---> ' + repr(value)