# -*- ruby -*-

# vim: set noet nosta sw=4 ts=4 :

require 'arborist/monitor/snmp' unless defined?( Arborist::Monitor::SNMP )

# SNMP 5 minute load checks.

# Sets current 5 minute load as a 'load5' attribute.

#

class Arborist::Monitor::SNMP::Load

	include Arborist::Monitor::SNMP

	extend Loggability

	log_to :arborist

	# OIDS for discovering system load.

	#

	LOAD = {

		five_min: '1.3.6.1.4.1.2021.10.1.3.2'

	}

	# Global defaults for instances of this monitor

	#

	DEFAULT_OPTIONS = {

		error_at: 7

	}

	### Class #run creates a new instance.

	###

	def self::run( nodes )

		return new.run( nodes )

	end

	### Create a new instance of this monitor.

	###

	def initialize( options=DEFAULT_OPTIONS )

		options = DEFAULT_OPTIONS.merge( options || {} )

		options.each do |name, value|

			self.public_send( "#{name.to_s}=", value )

		end

	end

	# Set an error if mount points are above this percentage.

	attr_accessor :error_at

	### Perform the monitoring checks.

	###

	def run( nodes )

		super do |snmp, host|

			self.gather_load( snmp, host )

		end

	end

	#########

	protected

	#########

	### Collect the load information for +host+ from an existing

	### (and open) +snmp+ connection.

	###

	def gather_load( snmp, host )

		self.log.debug "Getting system load for: %s" % [ host ]

		load5 = snmp.get( SNMP::ObjectId.new( LOAD[:five_min] ) ).varbind_list.first.value.to_f

		self.log.debug "  Load on %s: %0.2f" % [ host, load5 ]

		config = @identifiers[ host ].last || {}

		error_at = config[ 'error_at' ] || self.error_at

		if load5 >= error_at

			@results[ host ] = {

				error: "Load has exceeded %0.2f over a 5 minute average" % [ error_at ],

				load5: load5

			}

		else

			@results[ host ] = { load5: load5 }

		end

	end

end # class Arborist::Monitor::SNMP::Load