Server health endpoint based on @dshaw's JSDay tip

health-endpoint.rb

# In his JSDay talk (online here: http://dshaw.github.com/2012-05-jsday/), @dshaw proposed having a
# 'health' endpoint for Node servers that gave you important system stats.
#
# Here's an example of what that would look like for Sinatra.

require "time"
require "sinatra"
require "json"

get "/health" do
  uptime = Time.parse `last | tail -1`

  stats = {
    "pid" => $$.to_s,
    "current_memory_usage" => `ps -o rss= -p #{Process.pid}`.to_i.to_s,
    "up_since" => uptime.to_s, # gets uptime of WHOLE MACHINE, TODO: change to time we start execution
    "time_of_request" => Time.now.to_s
  }

  body stats.to_json
  status 200
end

# TODO: number of current connections