#!/usr/bin/env ruby

# Source: https://github.com/cmur2/munin-dovecot

#
# Example usage:
#  Do
#    ln -s /path/to/dovecot_ dovecot_<mode>
#  where <mode> is one of connections.
#
# Example config:
#  [dovecot_*]
#

require 'csv'
require 'open-uri'

script = File.basename($0)
@mode = script.gsub('dovecot_', '')
@cmd = ARGV[0]

def echo_connections()
	case @cmd
	when 'config'
		puts "graph_title Dovecot connections"
		puts "graph_args --lower-limit 0"
		puts "graph_vlabel connections"
		puts "graph_category dovecot"
		puts "graph_scale no"
		puts "graph_info This graph shows the number of connections to Dovecot."
		puts "nimap.label imap"
		puts "nimap.info Number of imap connections currently open."
		puts "nimap.type GAUGE"
	else
		output = `doveadm oldstats dump session connected`
		csv_data = CSV.parse(output, {:col_sep => "\t"})
		exit 1 if csv_data.empty?
		puts "nimap.value #{csv_data.select { |x| x[3] == 'imap'}.size}"
	end
end

# open stderr
$stderr = IO.new(2, "w")

case @mode
when 'connections'
	echo_connections()
else
	$stderr.puts "Unknown mode #{@mode} for dovecot_!"
	exit 3
end