|
| 1 | +import asyncio |
| 2 | +from . import logger, constants |
| 3 | +from .mib import ValueType |
| 4 | +from .encodings import ObjectIdentifier, ValueRepresentation |
| 5 | +from .pdu import PDUHeader |
| 6 | +from .pdu_implementations import NotifyPDU |
| 7 | +import re |
| 8 | +import json |
| 9 | +import os |
| 10 | + |
| 11 | +class TrapInfra: |
| 12 | + """ |
| 13 | + Trap infrastructure's core services are define here. |
| 14 | + """ |
| 15 | + protocol_obj = None # this will be set in the AgentX protocol class |
| 16 | + def __init__(self, loop, trap_handlers): |
| 17 | + logger.debug("Init begins for Trap infra") |
| 18 | + self.loop = loop |
| 19 | + self.redis_instances = dict() |
| 20 | + self.db_to_redis_dict = dict() |
| 21 | + if trap_handlers is None: |
| 22 | + return |
| 23 | + self.dbKeyToHandler = dict() |
| 24 | + trap_handlers_set = set(trap_handlers) |
| 25 | + for t_handler in trap_handlers_set: |
| 26 | + t_instance = t_handler() |
| 27 | + dbKeys = t_instance.dbKeys |
| 28 | + for dbkey in dbKeys: |
| 29 | + if dbkey not in self.dbKeyToHandler: |
| 30 | + self.dbKeyToHandler[dbkey] = list() |
| 31 | + self.dbKeyToHandler[dbkey].append(t_instance) |
| 32 | + else: |
| 33 | + self.dbKeyToHandler[dbkey].append(t_instance) |
| 34 | + t_instance.trap_init() |
| 35 | + logger.debug("Init successful for Trap infra") |
| 36 | + |
| 37 | + async def db_listener(self): |
| 38 | + """ |
| 39 | + Co routine which listens for DB notification events |
| 40 | + """ |
| 41 | + import aioredis |
| 42 | + from aioredis.pubsub import Receiver |
| 43 | + |
| 44 | + logger.debug("starting redis co routine") |
| 45 | + logger.info("starting redis DB listener routine") |
| 46 | + # Read Config File and setup DB instances |
| 47 | + CONFIG_FILE = os.getenv('DB_CONFIG_FILE', "/var/run/redis/sonic-db/database_config.json") |
| 48 | + if not os.path.exists(CONFIG_FILE): |
| 49 | + raise RuntimeError("[Trap:db_listener - DB config file not found " + str(CONFIG_FILE)) |
| 50 | + else: |
| 51 | + with open(CONFIG_FILE, "r") as config_file: |
| 52 | + db_config_data = json.load(config_file) |
| 53 | + if not 'INSTANCES' in db_config_data: |
| 54 | + raise RuntimeError("[Trap:db_listener - No DB instances found in DB config file") |
| 55 | + for instance in db_config_data['INSTANCES']: |
| 56 | + entry = db_config_data['INSTANCES'][instance] |
| 57 | + if instance not in self.redis_instances: |
| 58 | + self.redis_instances[instance] = {"host": entry["hostname"], \ |
| 59 | + "port": entry["port"], "keyPatterns": [], \ |
| 60 | + "patternObjs": [], "receiver_handle": None, \ |
| 61 | + "connection_obj": None \ |
| 62 | + } |
| 63 | + for db in db_config_data['DATABASES']: |
| 64 | + entry = db_config_data['DATABASES'][db] |
| 65 | + db_id = int(entry["id"]) |
| 66 | + if db_id not in self.db_to_redis_dict: |
| 67 | + if entry["instance"] not in self.redis_instances: |
| 68 | + raise RuntimeError("[Trap:db_listener - No DB instance found for " + str(entry["instance"])) |
| 69 | + self.db_to_redis_dict[db_id] = self.redis_instances[entry["instance"]] |
| 70 | + |
| 71 | + async def reader(receiver_handle): |
| 72 | + logger.debug("Listening for notifications") |
| 73 | + async for channel, msg in receiver_handle.iter(): |
| 74 | + logger.debug("Got {!r} in channel {!r}".format(msg, channel)) |
| 75 | + self.process_trap(channel,msg) |
| 76 | + |
| 77 | + for instance in self.redis_instances: |
| 78 | + address_tuple = (self.redis_instances[instance]['host'], self.redis_instances[instance]['port']) |
| 79 | + self.redis_instances[instance]["connection_obj"] = await aioredis.create_redis_pool(address_tuple) |
| 80 | + receiver_handle = Receiver(loop=self.loop) |
| 81 | + self.redis_instances[instance]["receiver_handle"] = receiver_handle |
| 82 | + asyncio.ensure_future(reader(receiver_handle)) |
| 83 | + |
| 84 | + for pat in self.dbKeyToHandler.keys(): |
| 85 | + #Get DB number |
| 86 | + db_num = re.match(r'__keyspace@(\d+)__:',pat).group(1) |
| 87 | + if db_num is None or db_num == "": |
| 88 | + raise RuntimeError("[Trap:db_listener - DB number cannot be determined for key " + str(pat)) |
| 89 | + |
| 90 | + db_num = int(db_num) |
| 91 | + db_instance = self.db_to_redis_dict[db_num] |
| 92 | + db_instance["patternObjs"].append(db_instance["receiver_handle"].pattern(pat)) |
| 93 | + db_instance["keyPatterns"].append(pat) |
| 94 | + |
| 95 | + for instance in self.redis_instances: |
| 96 | + if len(self.redis_instances[instance]["patternObjs"]) == 0: |
| 97 | + continue |
| 98 | + await self.redis_instances[instance]["connection_obj"].psubscribe(*self.redis_instances[instance]["patternObjs"]) |
| 99 | + |
| 100 | + def dispatch_trap(self, varBinds): |
| 101 | + """ |
| 102 | + Prepare Notify PDU and sends to Master using AgentX protocol |
| 103 | + """ |
| 104 | + logger.debug("dispatch_trap invoked") |
| 105 | + if TrapInfra.protocol_obj is not None: |
| 106 | + notifyPDU = NotifyPDU(header=PDUHeader(1, \ |
| 107 | + constants.PduTypes.NOTIFY, \ |
| 108 | + PDUHeader.MASK_NEWORK_BYTE_ORDER, 0, \ |
| 109 | + TrapInfra.protocol_obj.session_id, \ |
| 110 | + 0, 0, 0), varBinds=varBinds) |
| 111 | + TrapInfra.protocol_obj.send_pdu(notifyPDU) |
| 112 | + logger.debug("processed trap successfully") |
| 113 | + else: |
| 114 | + logger.warning("Protocol Object is None, cannot process traps") |
| 115 | + |
| 116 | + def process_trap(self, channel, msg): |
| 117 | + """ |
| 118 | + Invokes trap handlers |
| 119 | + """ |
| 120 | + db_pattern = channel.name.decode('utf-8') |
| 121 | + changed_key = msg[0].decode('utf-8') |
| 122 | + |
| 123 | + for t_instance in self.dbKeyToHandler[db_pattern]: |
| 124 | + varbindsDict = t_instance.trap_process(msg, changed_key) |
| 125 | + if varbindsDict is None: |
| 126 | + continue # no process |
| 127 | + assert isinstance(varbindsDict, dict) |
| 128 | + assert 'TrapOid' in varbindsDict |
| 129 | + assert 'varBinds' in varbindsDict |
| 130 | + varbinds = varbindsDict['varBinds'] |
| 131 | + TrapOid = varbindsDict['TrapOid'] |
| 132 | + assert isinstance(TrapOid, ObjectIdentifier) |
| 133 | + varbindsList = [] |
| 134 | + # Insert standard SNMP trap |
| 135 | + snmpTrapOid = ObjectIdentifier(11, 0, 0, 0, (1, 3, 6, 1, 6, 3, 1, 1, 4, 1, 0)) |
| 136 | + snmpTrapVarBind = ValueRepresentation(ValueType.OBJECT_IDENTIFIER, 0, snmpTrapOid, TrapOid) |
| 137 | + varbindsList.append(snmpTrapVarBind) |
| 138 | + if len(varbinds) > 0: |
| 139 | + for vb in varbinds: |
| 140 | + if not isinstance(vb, ValueRepresentation): |
| 141 | + raise RuntimeError("list entry is not of type ValueRepresentation") |
| 142 | + else: |
| 143 | + varbindsList.append(vb) |
| 144 | + else: |
| 145 | + raise RuntimeError("Return value must contain atleast one VarBind") |
| 146 | + self.dispatch_trap(varbindsList) |
| 147 | + |
| 148 | + async def shutdown(self): |
| 149 | + for instance in self.redis_instances: |
| 150 | + if len(self.redis_instances[instance]["keyPatterns"]) > 0: |
| 151 | + await self.redis_instances[instance]["connection_obj"].punsubscribe(*self.redis_instances[instance]["keyPatterns"]) |
| 152 | + self.redis_instances[instance]["receiver_handle"].stop() |
| 153 | + self.redis_instances[instance]["connection_obj"].close() |
| 154 | + await self.redis_instances[instance]["connection_obj"].wait_closed() |
| 155 | + |
| 156 | +class Trap: |
| 157 | + """ |
| 158 | + Interface for developing Trap handlers |
| 159 | + """ |
| 160 | + def __init__(self, **kwargs): |
| 161 | + self.run_event = asyncio.Event() |
| 162 | + assert isinstance(kwargs["dbKeys"], list) |
| 163 | + self.dbKeys = kwargs["dbKeys"] |
| 164 | + |
| 165 | + def trap_init(self): |
| 166 | + """ |
| 167 | + Children may override this method. |
| 168 | + """ |
| 169 | + logger.info("I am trap_init from infra") |
| 170 | + |
| 171 | + def trap_process(self, dbMessage, changedKey): |
| 172 | + """ |
| 173 | + Children may override this method. |
| 174 | + """ |
| 175 | + logger.info("I am trap_process from infra") |
| 176 | + |
| 177 | + |
| 178 | + |
| 179 | + |
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