# -*- ruby -*-

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

#encoding: utf-8

#

# SNMP checks for Arborist.  Requires an SNMP agent to be installed

# on target machine, and the various "pieces" enabled.  For your platform.

#

# For example, for disk monitoring with Net-SNMP, you'll want to set

# 'includeAllDisks' in the snmpd.conf. bsnmpd on FreeBSD benefits from

# the 'bsnmp-ucd' package.  Etc.

#

require 'loggability'

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

require 'snmp'

using Arborist::TimeRefinements

# Shared SNMP monitor logic.

#

module Arborist::Monitor::SNMP

	extend Loggability

	log_to :arborist

	# The version of this library.

	VERSION = '0.3.0'

	# Global defaults for instances of this monitor

	#

	DEFAULT_OPTIONS = {

		timeout:   2,

		retries:   1,

		community: 'public',

		port:      161

	}

	### Connect to the SNMP daemon and yield.

	###

	def run( nodes )

		self.log.debug "Got nodes to SNMP check: %p" % [ nodes ]

		opts = Arborist::Monitor::SNMP::DEFAULT_OPTIONS

		# Create mapping of addresses back to node identifiers,

		# and retain any custom (overrides) config per node.

		#

		@identifiers = {}

		@results     = {}

		nodes.each_pair do |(identifier, props)|

			next unless props.key?( 'addresses' )

			address = props[ 'addresses' ].first

			@identifiers[ address ] = [ identifier, props['config'] ]

		end

		# Perform the work!

		#

		threads = []

		@identifiers.keys.each do |host|

			thr = Thread.new do

				Thread.current.abort_on_exception = true

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

				opts = {

					host:      host,

					port:      config[ 'port' ]      || opts[ :port ],

					community: config[ 'community' ] || opts[ :community ],

					timeout:   config[ 'timeout' ]   || opts[ :timeout ],

					retries:   config[ 'retries' ]   || opts[ :retries ]

				}

				begin

					SNMP::Manager.open( opts ) do |snmp|

						yield( snmp, host )

					end

				rescue SNMP::RequestTimeout

					@results[ host ] = {

						error: "Host is not responding to SNMP requests."

					}

				rescue StandardError => err

					@results[ host ] = {

						error: "Network is not accessible. (%s: %s)" % [ err.class.name, err.message ]

					}

				end

			end

			threads << thr

		end

		# Wait for thread completion

		threads.map( &:join )

		# Map everything back to identifier -> attribute(s), and send to the manager.

		#

		reply = @results.each_with_object({}) do |(address, results), hash|

			identifier = @identifiers[ address ] or next

			hash[ identifier.first ] = results

		end

		self.log.debug "Sending to manager: %p" % [ reply ]

		return reply

	ensure

		@identifiers = {}

		@results     = {}

	end

end # Arborist::Monitor::SNMP

require 'arborist/monitor/snmp/disk'

require 'arborist/monitor/snmp/load'

require 'arborist/monitor/snmp/memory'

require 'arborist/monitor/snmp/process'

require 'arborist/monitor/snmp/swap'