Snmp checks

.travis.yml

@@ -25,6 +25,7 @@ before_install:
   - sudo apt-get install couchdb
   - sudo apt-get install lighttpd
   - sudo apt-get install gearman
+  - sudo apt-get install snmpd
 install:
   - pip install -r requirements.txt --use-mirrors
   - pip install . --use-mirrors
@@ -51,11 +52,14 @@ before_script:
   - sudo mkdir -p /etc/dd-agent/
   - sudo install -d -o "$(id -u)" /var/log/datadog
   - sudo bash -c "curl -L https://raw.github.com/DataDog/dd-agent/master/datadog.conf.example > /etc/dd-agent/datadog.conf"
+  - sudo service snmpd stop
+  - sudo bash -c "curl -L https://raw.github.com/DataDog/dd-agent/SNMP_checks/tests/snmp/snmpd.conf > /etc/snmp/snmpd.conf" # referring wrong branch during development
   - sudo service apache2 start
   - sudo service nginx start
   - sudo /etc/init.d/lighttpd start
   - sudo service tomcat6 restart
   - sudo service couchdb start
+  - sudo service snmpd start
 env:
   - DB=redis
 script:

checks.d/snmp.py

@@ -0,0 +1,257 @@
+# std
+from collections import defaultdict
+
+# project
+from checks import AgentCheck
+
+# 3rd party
+from pysnmp.entity.rfc3413.oneliner import cmdgen
+from pysnmp.smi.exval import noSuchInstance, noSuchObject
+from pysnmp.smi import builder
+import pysnmp.proto.rfc1902 as snmp_type
+
+# Additional types that are not part of the SNMP protocol. cf RFC 2856
+(CounterBasedGauge64, ZeroBasedCounter64) = builder.MibBuilder().importSymbols("HCNUM-TC","CounterBasedGauge64", "ZeroBasedCounter64")
+
+# Metric type that we support
+SNMP_COUNTERS = [snmp_type.Counter32.__name__, snmp_type.Counter64.__name__, ZeroBasedCounter64.__name__]
+SNMP_GAUGES = [snmp_type.Gauge32.__name__, CounterBasedGauge64.__name__]
+
+# IF-MIB magic values
+IF_TABLE_OID = '.1.3.6.1.2.1.2.2.1.'
+IF_TABLE_TYPE_POS = 9
+IF_TABLE_INDEX_POS = 10
+IF_DESCR = 2
+IF_TYPE = 3
+LOCALHOST_INTERFACE = 24
+
+def reply_invalid(oid):
+    return noSuchInstance.isSameTypeWith(oid) or \
+           noSuchObject.isSameTypeWith(oid)
+
+class SnmpCheck(AgentCheck):
+
+    cmd_generator = None
+
+    def __init__(self, name, init_config, agentConfig, instances=None):
+        AgentCheck.__init__(self, name, init_config, agentConfig, instances)
+
+        self.interface_list = {}
+
+        # Load Custom MIB directory
+        mibs_path = None
+        if init_config is not None:
+            mibs_path = init_config.get("mibs_folder")
+        SnmpCheck.create_command_generator(mibs_path)
+
+        # Detect the interfaces of the instance and retain their indexes
+        if instances is not None:
+            for instance in instances:
+                if 'ip_address' in instance:
+                    ip_address = instance["ip_address"]
+                    self.interface_list[ip_address] = self.get_interfaces(instance)
+
+    @classmethod
+    def create_command_generator(cls, mibs_path=None):
+        '''
+        Create a command generator to perform all the snmp query
+        If mibs_path is not None, load the mibs present in the custom mibs
+        folder (Need to be in pysnmp format)
+        '''
+        cls.cmd_generator = cmdgen.CommandGenerator()
+        if mibs_path is not None:
+            mib_builder = cls.cmd_generator.snmpEngine.msgAndPduDsp.\
+                          mibInstrumController.mibBuilder
+            mib_sources = mib_builder.getMibSources() + (
+                    builder.DirMibSource(mibs_path),
+                    )
+            mib_builder.setMibSources(*mib_sources)
+
+    def get_interfaces(self, instance):
+        '''
+        Query the IF-MIB table to get the list of interfaces and their description
+        Ignore the interfaces that are loopback (localhost)
+        The nextCmd will return all the value in a format like this:
+
+            [(1.3.6.1.2.1.2.2.1.{what type of information}.{index of the interface}, information)]
+
+        For now we only care about the index, the description(eg. interface name eth0) and the type
+        to ignore the loopback interface
+        See http://www.alvestrand.no/objectid/1.3.6.1.2.1.2.2.1.html for more info about the table
+        '''
+        interface_list = {}
+        transport_target = self.get_transport_target(instance)
+        auth_data = self.get_auth_data(instance)
+
+        snmp_command = self.cmd_generator.nextCmd
+        error_indication, error_status, error_index, var_binds = snmp_command(
+            auth_data,
+            transport_target,
+            IF_TABLE_OID,
+            lookupValues = True
+            )
+
+        if_table = defaultdict(dict)
+        if error_indication:
+            raise Exception("{0} for instance {1}".format(error_indication, instance["ip_address"]))
+        else:
+            if error_status:
+                raise Exception("{0} for instance {1}".format(error_status.prettyPrint(), instance["ip_address"]))
+            else:
+                for table_row in var_binds:
+                    for name, val in table_row:
+                        if_table[name.asTuple()[IF_TABLE_INDEX_POS]][name.asTuple()[IF_TABLE_TYPE_POS]] = val
+
+        self.log.debug("Interface Table discovered %s" % if_table)
+        for index in if_table:
+            type = if_table[index].get(IF_TYPE)
+            descr = if_table[index].get(IF_DESCR)
+            if not reply_invalid(type):
+                if int(type) != LOCALHOST_INTERFACE and not reply_invalid(descr):
+                    interface_list[index] = str(descr)
+                    self.log.info("Discovered interface %s" % str(descr))
+
+        return interface_list
+
+    @classmethod
+    def get_auth_data(cls, instance):
+        '''
+        Generate a Security Parameters object based on the configuration of the instance
+        See http://pysnmp.sourceforge.net/docs/current/security-configuration.html
+        '''
+        if "community_string" in instance:
+            # SNMP v1 - SNMP v2
+            return cmdgen.CommunityData(instance['community_string'])
+        elif "user" in instance:
+            # SNMP v3
+            user = instance["user"]
+            auth_key = None
+            priv_key = None
+            auth_protocol = None
+            priv_protocol = None
+            if "authKey" in instance:
+                auth_key = instance["authKey"]
+                auth_protocol = cmdgen.usmHMACMD5AuthProtocol
+            if "privKey" in instance:
+                priv_key = instance["privKey"]
+                auth_protocol = cmdgen.usmHMACMD5AuthProtocol
+                priv_protocol = cmdgen.usmDESPrivProtocol
+            if "authProtocol" in instance:
+                auth_protocol = getattr(cmdgen, instance["authProtocol"])
+            if "privProtocol" in instance:
+                priv_protocol = getattr(cmdgen, instance["privProtocol"])
+            return cmdgen.UsmUserData(user, auth_key, priv_key, auth_protocol, priv_protocol)
+        else:
+            raise Exception("An authentication method needs to be provided")
+
+    @classmethod
+    def get_transport_target(cls, instance):
+        '''
+        Generate a Transport target object based on the configuration of the instance
+        '''
+        if "ip_address" not in instance:
+            raise Exception("An IP address needs to be specified")
+        ip_address = instance["ip_address"]
+        port = instance.get("port", 161) # Default SNMP port
+        return cmdgen.UdpTransportTarget((ip_address, port))
+
+    def check(self, instance):
+        tags = instance.get("tags",[])
+        ip_address = instance["ip_address"]
+        device_oids = []
+        oid_names ={}
+
+        # Check the metrics completely defined
+        for metric in instance.get('metrics', []):
+            if 'MIB' in metric:
+                device_oids.append(((metric["MIB"], metric["symbol"]), metric["index"]))
+            elif 'OID' in metric:
+                device_oids.append(metric['OID'])
+                # Associate the name to the OID so that we can perform the matching
+                oid_names[metric['OID']] = metric['name']
+            else:
+                raise Exception('Unsupported metrics format in config file')
+        self.log.debug("Querying device %s for %s oids", ip_address, len(device_oids))
+        results = SnmpCheck.snmp_get(instance, device_oids)
+        for oid, value in results:
+            self.submit_metric(instance, oid, value, tags=tags + ["snmp_device:" + ip_address],
+                                                     oid_names = oid_names)
+
+        # Check the metrics defined per interface by appending the index
+        # of the table to create a fully defined metric
+        interface_oids = []
+        for metric in instance.get('interface_metrics', []):
+            interface_oids.append((metric["MIB"], metric["symbol"]))
+        for interface, descr in self.interface_list[instance['ip_address']].items():
+            oids = [(oid, interface) for oid in interface_oids]
+            self.log.debug("Querying device %s for %s oids", ip_address, len(oids))
+            interface_results = SnmpCheck.snmp_get(instance, oids)
+            for oid, value in interface_results:
+                self.submit_metric(instance, oid, value, tags = tags + ["snmp_device:" + ip_address,
+                                                                            "interface:"+descr])
+
+    @classmethod
+    def snmp_get(cls, instance, oids):
+        """
+        Perform a snmp get command to the device that instance
+        describe and return a list of tuble (name, values)
+        corresponding to the elements in oids.
+        """
+        transport_target = cls.get_transport_target(instance)
+        auth_data = cls.get_auth_data(instance)
+
+
+        snmp_command = cls.cmd_generator.getCmd
+        error_indication, error_status, error_index, var_binds = snmp_command(
+                auth_data,
+                transport_target,
+                *oids,
+                lookupNames=True,
+                lookupValues=True
+                )
+
+        if error_indication:
+            raise Exception("{0} for instance {1}".format(error_indication, instance["ip_address"]))
+        else:
+            if error_status:
+                raise Exception("{0} for instance {1}".format(error_status.prettyPrint(), instance["ip_address"]))
+            else:
+                return var_binds
+
+    def submit_metric(self, instance, oid, snmp_value, tags=[], oid_names={}):
+        '''
+        Convert the values reported as pysnmp-Managed Objects to values and
+        report them to the aggregator
+        '''
+        if reply_invalid(snmp_value):
+            # Metrics not present in the queried object
+            self.log.warning("No such Mib available: %s" %oid.getMibSymbol()[1])
+            return
+
+        # Get the name for the OID either from the name that we can decode
+        # or from the name that was specified for it
+        if str(oid.getOid()) in oid_names:
+            name = "snmp."+ oid_names[str(oid.getOid())]
+        else:
+            try:
+                name = "snmp." + oid.getMibSymbol()[1]
+            except Exception:
+                self.log.warning("Couldn't find a name for oid {0}".format(oid))
+                return
+
+        # Ugly hack but couldn't find a cleaner way
+        # Proper way would be to use the ASN1 method isSameTypeWith but this
+        # returns True in the case of CounterBasedGauge64 and Counter64 for example
+        snmp_class = snmp_value.__class__.__name__
+        for counter_class in SNMP_COUNTERS:
+            if snmp_class==counter_class:
+                value = int(snmp_value)
+                self.rate(name, value, tags)
+                return
+        for gauge_class in SNMP_GAUGES:
+            if snmp_class==gauge_class:
+                value = int(snmp_value)
+                self.gauge(name, value, tags)
+                return
+        self.log.warning("Unsupported metric type %s", snmp_class)
+

conf.d/snmp.yaml.example

@@ -0,0 +1,59 @@
+init_config:
+#    #You can specify an additional folder for your custom mib files (python format)
+#    mibs_folder: /path/to/your/mibs/folder
+
+instances:
+
+     # SNMP v1-v2 configuration
+
+#    -   ip_address: localhost
+#        port: 161
+#        community_string: public
+#        tags:
+#            - optional_tag_1
+#            - optional_tag_2
+#
+#        # Device metrics to monitor
+#        metrics:
+#        # You can specify metrics using MIBS
+#            - MIB: UDP-MIB
+#              symbol: udpInDatagrams
+#              index: 0
+#            - MIB: TCP-MIB
+#              symbol: tcpActiveOpens
+#              index: 0
+#            - MIB: TCP-MIB
+#              symbol: tcpPassiveOpens
+#              index: 0
+#        # You can also specify an oid and the name under which it should appear
+#        # in Datadog
+#            - OID: 1.3.6.1.2.1.6.9.0
+#              name: tcpConnections
+#
+#        # Metrics to monitor on each interface
+#        interface_metrics:
+#            - MIB: IF-MIB
+#              symbol: ifInOctets
+#            - MIB: IF-MIB
+#              symbol: ifOutOctets
+
+     # SNMP v3 configuration
+     # check http://pysnmp.sourceforge.net/docs/current/security-configuration.html
+
+#    -   ip_address: localhost
+#        port: 161 # default value
+#        user: user
+#        authKey: password
+#        privKey: private_key
+#        authProtocol: authProtocol
+#        privProtocol: privProtocol
+#        tags:
+#           - optional_tag_1
+#           - optional_tag_2
+#
+#        # Metrics to monitor on each interface
+#        interface_metrics:
+#            - MIB: IF-MIB
+#              symbol: ifInOctets
+#            - MIB: IF-MIB
+#              symbol: ifOutOctets

requirements.txt

@@ -9,6 +9,8 @@ psutil
 gearman
 pylint
 boto
+pysnmp
+pysnmp-mibs
 PyMySQL
 pg8000
 ntplib

tests/snmp/snmpd.conf

@@ -0,0 +1 @@
+rocommunity    public