WebFaction Memory Usage Script

memusage.rb

#!/usr/bin/env ruby

# Memory usage script for WebFaction customers adapted to attempt to 
# draw username from the pwd
# Nick Trew <vxnick@gmail.com>
# 2009-05-25

# START CONFIG #
require 'pathname'

# Put your username here
user = nil

# if no username is defined, attempt to grab it from the pwd
user ||= Pathname.pwd.dirname.to_s.split("/")[2]

puts "Calculating memory usage for:" + user

# Your memory limit (MB)
# This can be found at http://www.webfaction.com/services/hosting
# Enter "Application Memory" for whichever package you're on
memory_limit = 80

# END CONFIG #

# Get the process list and split at newlines
processes = `ps -u #{user} -o pid,rss,command`.split("\n")

# We'll keep a running total of each process' memory usage here
mem_count = 0.00

# Loop through the processes
processes.each_with_index do |line, index|
    # Ignore the "PID RSS COMMAND" line
    next if index == 0

    # Split at the first space we encounter to separate the PID, RSS and COMMAND info
    pid, rss, cmd = line.strip.sub(/\s+/, " ").split(/\s/, 3)

    # Add to the running total
    mem_count += rss.to_i
    
    # Output the process' memory usage and the associated command
    puts sprintf('PID:%d using %.2f MB: %s', pid.to_i, (rss.to_f) / 1024, cmd)
end

# Output the total memory usage for all the processes combined with the memory_limit specified above
puts sprintf('Total memory usage: %.2f MB / %d MB', (mem_count.to_f) / 1024, memory_limit)