alerta_alerta-contrib/integrations/snmptrap

SNMP Trap Integration

SNMP trap listener sends alerts to Alerta.

For help, join

Prerequisites

• Net-SNMP snmptrapd package - integration runs as a trap handler by Net-SNMP snmptrapd

To install net-snmp on RedHat/Centos Linux:

$ sudo yum -y install net-snmp net-snmp-utils

To install net-snmp on Ubuntu Xenial:

$ sudo apt install -y snmptrapd snmp

Installation

Clone the GitHub repo and run:

$ python setup.py install

Or, to install remotely from GitHub run:

$ pip install git+https://github.com/alerta/alerta-contrib.git#subdirectory=integrations/snmptrap

Configuration

Configure snmptrapd to execute alerta-snmptrap when an SNMP trap is received:

$ vi /etc/snmp/snmptrapd.conf

authCommunity log,execute,net public
format execute $a %a\n$A %A\n$s %s\n$b %b\n$B %B\n$x %#y-%#02m-%#02l\n$X %#02.2h:%#02.2j:%#02.2k\n$N %N\n$q %q\n$P %P\n$t %t\n$T %T\n$w %w\n$W %W\n%V~\%~%v\n
traphandle default alerta-snmptrap

Set Alerta API endpoint in the start-up script on RedHat/Centos:

$ vi /etc/sysconfig/snmptrapd

export ALERTA_ENDPOINT="http://localhost:8080"

Set Alerta API endpoint in the start-up script on Debian/Ubuntu:

$ vi /etc/default/snmptrapd

export ALERTA_ENDPOINT="http://localhost:8080"

Restart the snmptrapd service:

$ sudo service snmptrapd restart

Transform Plugin

By default, SNMP traps are assigned reasonable values for each alert attribute. However, to make SNMP traps useful sources of events it may be necessary to do additional processing and assign relevant values for resource, event, severity and others.

To achieve this in an extensible way, it is recommended to use a plugin that transforms the original "trapvar" values stored as attributes in the submitted SNMP trap alert to values like severity in the "pre-receive" hook.

Example Trapvars

  "alert": {
    "attributes": {
      "trapvars": {
        "_#": "3",
        "_1": "0:1:41:43.19",
        "_2": "iso.3.6.1.6.3.1.1.5.3.0",
        "_3": "\"This is a test linkDown trap\"",
        "_A": "0.0.0.0",
        "_B": "localhost",
        "_N": ".",
        "_O": "iso.3.6.1.6.3.1.1.5.3.0",
        "_P": "TRAP2, SNMP v2c, community public",
        "_T": "0",
        "_W": "Enterprise Specific",
        "_X": "15:05:45",
        "_a": "0.0.0.0",
        "_b": "UDP: [127.0.0.1]:48476->[127.0.0.1]:162",
        "_q": "0",
        "_s": "SNMPv2c",
        "_t": "1482073545",
        "_w": "6",
        "_x": "2016-12-18"
      }
    },
    ...

Example Transform Plugin for Oracle EM Traps

class OracleTrapTransformer(PluginBase):

    def pre_receive(self, alert):

        alert.resource = alert.attributes['trapvars']['_3'].split('.',1)[0]

        if alert.attributes['trapvars']['_10'] in ['Serious', 'Critical']: # oraEM4AlertSeverity
            alert.severity = 'critical'
        elif alert.attributes['trapvars']['_10'] == 'Error'
            alert.severity = 'major'
        else:
            alert.severity = 'normal'

        alert.event = alert.attributes['trapvars']['_6'].replace(' ','')   # oraEM4AlertMetricName
        alert.value = alert.attributes['trapvars']['_14']                  # oraEM4AlertMetricValue
        alert.text = alert.attributes['trapvars']['_11']                   # oraEM4AlertMessage

        return alert

    def post_receive(self, alert):
        ...

Troubleshooting

Stop snmptrapd and run it in the foreground:

$ sudo service snmptrapd stop
$ sudo ALERTA_ENDPOINT="http://10.0.2.2:8080" snmptrapd -Lsd -p /var/run/snmptrapd.pid -f

Tail syslog file:

$ tail -f /var/log/messages

Send test trap:

$ snmptrap -v2c -c public localhost "" .1.3.6.1.6.3.1.1.5.3.0 0 s "This is a test linkDown trap"

References

• Configuring SNMP Trapd: http://net-snmp.sourceforge.net/wiki/index.php/TUT:Configuring_snmptrapd

License

Copyright (c) 2014-2016 Nick Satterly. Available under the MIT License.