"""
SNMPv3 INFORM, auth: MD5, privacy: none
+++++++++++++++++++++++++++++++++++++++

Send SNMP INFORM notification using the following options:

* SNMPv3
* with user 'usr-md5-none', auth: MD5, priv NONE
* over IPv4/UDP
* to a Manager at 127.0.0.1:162
* send INFORM notification
* with TRAP ID 'warmStart' specified as an OID
* include managed object information 1.3.6.1.2.1.1.5.0 = 'system name'

Functionally similar to:

| $ snmpinform -v3 -l authNoPriv -u usr-md5-none -A authkey1 demo.snmplabs.com  0 1.3.6.1.6.3.1.1.5.1 1.3.6.1.2.1.1.5.0 = 'system name'

"""#
from pysnmp.entity import engine, config
from pysnmp.carrier.asyncore.dgram import udp
from pysnmp.entity.rfc3413 import ntforg
from pysnmp.proto.api import v2c

# Create SNMP engine instance
snmpEngine = engine.SnmpEngine()

# Add USM user
config.addV3User(
    snmpEngine, 'usr-md5-none',
    config.usmHMACMD5AuthProtocol, 'authkey1'
)
config.addTargetParams(snmpEngine, 'my-creds', 'usr-md5-none', 'authNoPriv')

# Setup transport endpoint and bind it with security settings yielding
# a target name
config.addTransport(
    snmpEngine,
    udp.domainName,
    udp.UdpSocketTransport().openClientMode()
)
config.addTargetAddr(
    snmpEngine, 'my-nms',
    udp.domainName, ('127.0.0.1', 162),
    'my-creds',
    tagList='all-my-managers'
)

# Specify what kind of notification should be sent (TRAP or INFORM),
# to what targets (chosen by tag) and what filter should apply to
# the set of targets (selected by tag)
config.addNotificationTarget(
    snmpEngine, 'my-notification', 'my-filter', 'all-my-managers', 'inform'
)

# Allow NOTIFY access to Agent's MIB by this SNMP model (3), securityLevel
# and SecurityName
config.addContext(snmpEngine, '')
config.addVacmUser(snmpEngine, 3, 'usr-md5-none', 'authNoPriv', (), (), (1,3,6))

# *** SNMP engine configuration is complete by this line ***

# Create Notification Originator App instance. 
ntfOrg = ntforg.NotificationOriginator()
 
# Error/confirmation receiver
def cbFun(snmpEngine, sendRequestHandle, errorIndication,
          errorStatus, errorIndex, varBinds, cbCtx):
    print('Notification %s, status - %s' % (
        sendRequestHandle, errorIndication and errorIndication or 'delivered'
      )
    )

# Build and submit notification message to dispatcher
sendRequestHandle = ntfOrg.sendVarBinds(
    snmpEngine,
    'my-notification',  # notification targets
    None, '',           # contextEngineId, contextName
    # var-binds: SNMPv2-MIB::coldStart, ...
    [ ((1,3,6,1,6,3,1,1,5,1), v2c.ObjectIdentifier((1,3,6,1,6,3,1,1,5,1))),
      ((1,3,6,1,2,1,1,5,0), v2c.OctetString('system name')) ],
    cbFun
)

print('Notification %s scheduled to be sent' % sendRequestHandle)

# Run I/O dispatcher which would send pending message and process response
snmpEngine.transportDispatcher.runDispatcher()