passenger_nginx_memory_status.rb

#!/usr/bin/env ruby                                                                                                           

def output_config
  puts <<-END
graph_category passenger                                                                                                      
graph_title memory                                                                                                            
graph_vlabel megabytes                                                                                                        
graph_info This graph shows the memory consumption made by passenger processes, passenger and nginx.                          
graph_order nginx passenger rails                                                                                             
rails.label rails                                                                                                             
rails.draw AREA                                                                                                               
rails.info Total memory used by all rails processes.                                                                          
passenger.label passenger                                                                                                     
passenger.draw AREA                                                                                                           
passenger.info Total memory used by passenger.                                                                                
nginx.label nginx                                                                                                             
nginx.draw AREA                                                                                                               
nginx.info Total memory used by nginx.                                                                                        
END
  exit 0
end

def total_for(component, str)
  str.scan(/\d+\s+\d+.\d+ MB\s+(\d+.\d+) MB\s+#{component}/).flatten.collect(&:to_f).inject(:+)
end

def output_values
  stats = `sudo passenger-memory-stats`
  unless $?.success?
    $stderr.puts "failed executing passenger-memory-stats"
    exit 1
  end

  puts "rails.value #{total_for 'Rails',         stats}",
       "passenger.value #{total_for 'Passenger', stats}",
       "nginx.value #{total_for 'nginx',         stats}"
end

if ARGV[0] == "config"
  output_config
else
  output_values
end