AWS Lambda python script for sending metric value to collectd server.

CollectdClient.py

#
# For sending metric value to collectd server.
#
# Usage:
#    from modules.CollectdClient import CollectdClient
#    COLLECTD_HOST = "collectd.example.com"
#    COLLECTD_PORT = 25826
#    client = CollectdClient(COLLECTD_HOST, COLLECTD_PORT)
#    client.putval('example-web-01', 'service', 'gauge', 'metric', 300, 1.2345)
#

import socket
import struct
import time

class CollectdClient:

    log = True

    def __init__(self, host='127.0.0.1', port=25826):
        self.address = (host, port)
        self.__set_codes()
        self.__connect()

    def __log(self, log):
        if self.log: print log

    def __set_codes(self):
        self.type_codes = {
            'host'            : 0x0000,
            'time'            : 0x0001,
            'plugin'          : 0x0002,
            'plugin_instance' : 0x0003,
            'type'            : 0x0004,
            'type_instance'   : 0x0005,
            'values'          : 0x0006,
            'interval'        : 0x0007,
        }
        self.long_int_codes = [
            self.type_codes['time'], self.type_codes['interval']
        ]
        self.string_codes = [
            self.type_codes['host'],
            self.type_codes['plugin'], self.type_codes['plugin_instance'],
            self.type_codes['type'], self.type_codes['type_instance'],
        ]
        self.value_codes = {
            'counter'  : 0,
            'gauge'    : 1,
            'derive'   : 2,
            'absolute' : 3,
        }
        self.value_strings = {
            'counter'  : "!Q",
            'gauge'    : "<d",
            'derive'   : "!q",
            'absolute' : "!Q",
        }

    def __connect(self):
        try:
            self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        except Exception as e:
            raise Exception("Can't connect server.\nERROR: %s" % e)

    def __message(self, host, plugin, type, type_instance, interval, value):
        start = "".join([
            self.__pack(type, self.type_codes['host'], host),
            self.__pack(type, self.type_codes['time'], time.time()),
            self.__pack(type, self.type_codes['plugin'], plugin),
            self.__pack(type, self.type_codes['plugin_instance'], ""),
            self.__pack(type, self.type_codes['type'], type),
            self.__pack(type, self.type_codes['interval'], interval),
        ])

        part = self.__pack(type, type_instance, value)
        return "".join([start, part])

    def __pack(self, type, id, value):
        if isinstance(id, basestring): #Value
            return "".join([
                self.__pack(type, self.type_codes['type_instance'], id),
                struct.pack("!HHH", self.type_codes['values'], 15, 1),
                struct.pack("<B", self.value_codes[type]),
                struct.pack(self.value_strings[type], value),
            ])
        elif id in self.long_int_codes: #Numeric
            return struct.pack("!HHq", id, 12, int(value))
        elif id in self.string_codes: #String
            value = str(value)
            return struct.pack("!HH", id, 5 + len(value)) + value + "\0"
        else:
            raise AssertionError("Invalid type code " + str(id))

    # This options is same as
    # "PUTVAL %s/%s/%s-%s interval=%d N:%f" % (host, plugin, type, type_instance, interval, value)
    # within collectd exec plugin
    def putval(self, host, plugin, type, type_instance, interval, value):
        if type != "gauge": value = int(value)
        vars = (host, plugin, type, type_instance, interval, value)
        self.__log("PUTVAL %s/%s/%s-%s interval=%d N:%s" % vars)
        message = self.__message(*vars)
        self.sock.sendto(message, self.address)

if __name__ == '__main__':
    client = CollectdClient()
    client.putval('example-web-01', 'service', 'gauge', 'metric', 300, 1.2345)