Ruby uWSGI DSL module

As well as the python Decorators, a DSL for ruby, allowing elegant uWSGI api access is available.

The module is available as uwsgidsl.rb in the source distribution.

You can put the code in your config.ru files, or in ruby files you will load with --rbrequire options (see below)

timer

execute code at regular interval

require 'uwsgidsl'

timer 30 do |signum|
  puts "30 seconds elapsed"
end

rbtimer

same as timer but using red black tree timer

require 'uwsgidsl'

rbtimer 30 do |signum|
  puts "30 seconds elapsed"
end

filemon

execute code at file modifications

require 'uwsgidsl'

filemon '/tmp' do |signum|
  puts "/tmp has been modified"
end

cron

execute task periodically using the CronInterface

require 'uwsgidsl'

cron 30,17,-1,-1,-1 do |signum|
  puts "it is 17:30 !!!"
end

signal

register code as a signal handler

require 'uwsgidsl'

signal 17 do |signum|
  puts "i am the uwsgi signal #{signum}"
end

postfork

execute code after each fork()

require 'uwsgidsl'

postfork do
  puts "uWSGI server called fork()"
end

rpc

register code as a RPC function

require 'uwsgidsl'

rpc 'helloworld' do
    return "Hello World"
end

rpc 'advancedhelloworld' do |x,y|
    return "x = #{x}, y = #{y}"
end

mule

Execute code as a Mule brain

require 'uwsgidsl'

mule 1 do
  puts "I am the mule #{UWSGI.mule_id}"
end

will run the code in mule 1

mule do
  puts "I am the mule #{UWSGI.mule_id}"
end

will run the code in the first available mule

After the function returns, the mule will be brainless.

To avoid this, put the code in a loop

mule 1 do
  loop do
    puts "I am the mule #{UWSGI.mule_id}"
    sleep(2)
  end
end

or even better:

muleloop

execute code in a mule in looped context

muleloop 3 do
  puts "I am the mule #{UWSGI.mule_id}"
  sleep(2)
end

SpoolProc

a subclass of Proc allowing you to define task to be executed in the Spooler

# define the function
my_long_running_task = SpoolProc.new {|args|
  puts "I am task1"
  UWSGI::SPOOL_OK
}

# spool it
my_long_running_task.call({'foo' => 'bar', 'one' => 'two'})

MuleFunc

call a function from any process (a worker for example) but execute in a mule

i_am_a_long_running_function = MuleFunc.new do |pippo,pluto|
  puts "i am mule #{UWSGI.mule_id} #{pippo}, #{pluto}"
end

i_am_a_long_running_function.call("serena", "alessandro")

the worker call i_am_a_long_running_function() but the function will be execute asynchronously in the first available mule.

If you want to run the function on a specific mule, simply use

i_am_a_long_running_function = MuleFunc.new 5 do |pippo,pluto|
  puts "i am mule #{UWSGI.mule_id} #{pippo}, #{pluto}"
end

i_am_a_long_running_function.call("serena", "alessandro")

this will use only the fifth mule

Real world usage

A simple sinatra app printing messages every 30 seconds

#config.ru
require 'rubygems'
require 'sinatra'
require 'uwsgidsl'

timer 30 do |signum|
  puts "30 seconds elapsed"
end

get '/hi' do
  "Hello World!"
end

run Sinatra::Application

or you can put your code in a dedicated file (mytasks.rb)

require 'uwsgidsl'

timer 30 do |signum|
  puts "30 seconds elapsed"
end

timer 60 do |signum|
  puts "60 seconds elapsed"
end

and loading it with

uwsgi --socket :3031 --rack config.ru --rbrequire mytasks.rb --master --processes 4

Status

The uWSGI api for ruby is still incomplete (QueueFramework, SharedArea, message/object passing and SNMP being the most missing players), the DSL will be extended as soon as the various api call will be ready.

Current available api functions and constants (available in UWSGI ruby module) are

UWSGI.suspend
UWSGI.masterpid
UWSGI.async_sleep
UWSGI.wait_fd_read
UWSGI.wait_fd_write
UWSGI.async_connect
UWSGI.signal
UWSGI.register_signal
UWSGI.register_rpc
UWSGI.signal_registered
UWSGI.signal_wait
UWSGI.signal_received
UWSGI.add_cron
UWSGI.add_timer
UWSGI.add_rb_timer
UWSGI.add_file_monitor
UWSGI.cache_get
UWSGI.cache_get!
UWSGI.cache_exists
UWSGI.cache_exists?
UWSGI.cache_del
UWSGI.cache_set
UWSGI.cache_set
UWSGI.cache_set!
UWSGI.cache_update
UWSGI.cache_update!
UWSGI.setprocname
UWSGI.set_warning_message
UWSGI.lock
UWSGI.unlock
UWSGI.mem
UWSGI.mule_get_msg
UWSGI.request_id
UWSGI.mule_id
UWSGI.mule_msg
UWSGI.worker_id
UWSGI.log
UWSGI.logsize
UWSGI.i_am_the_spooler
UWSGI.send_to_spooler
UWSGI.spool
UWSGI::OPT
UWSGI::VERSION
UWSGI::HOSTNAME
UWSGI::NUMPROC
UWSGI::PIDFILE
UWSGI::SPOOL_OK
UWSGI::SPOOL_RETRY
UWSGI::SPOLL_IGNORE