munin plugin to monitor Passenger Phusion memory stats (adapted for rvm)

Munin Passenger Phusion Memory Stats.rb

#!/usr/bin/env ruby
# put in /etc/munin/plugins and restart munin-node
# by Dan Manges, http://www.dcmanges.com/blog/rails-application-visualization-with-munin
# NOTE: you might need to add munin to allow passwordless sudo for passenger-memory-stats 
 
def output_config
  puts <<-END
graph_category App
graph_title Passenger memory stats 
graph_vlabel count

memory.label memory
END
  exit 0
end
 
def output_values
  status = `sudo /usr/local/bin/rvm-shell -c passenger-memory-stats | tail -1`
  #or use the line bellow if not using rvm
  #status = `sudo /usr/bin/passenger-memory-stats | tail -1` 
  unless $?.success?
    $stderr.puts "failed executing passenger-memory-stats"
    exit 1
  end
  status =~ /(\d+\.\d+)/
  puts "memory.value #{$1}"
end
 
if ARGV[0] == "config"
  output_config
else
  output_values
end