This is a clean import of Daemons 1.0.10, with the following changes:
- Applied Chris Kline's patch to "Making sure Ruby Daemons die" from http://blog.rapleaf.com/dev/?p=19.
- Added a gemspec to allow Github to build a gem.
- Includes ability to change the process uid/gid.
- logdir can be specified seperate from piddir.
(See Releases for release-specific information)
Daemons provides an easy way to wrap existing ruby scripts (for example a self-written server) to be run as a daemon and to be controlled by simple start/stop/restart commands.
If you want, you can also use daemons to run blocks of ruby code in a daemon process and to control these processes from the main application.
Besides this basic functionality, daemons offers many advanced features like exception backtracing and logging (in case your ruby script crashes) and monitoring and automatic restarting of your processes if they crash.
Daemons includes the daemonize.rb script written by Travis Whitton to do the daemonization process.
You can use Daemons in four differet ways:
Layout: suppose you have your self-written server myserver.rb:
# this is myserver.rb
# it does nothing really useful at the moment
loop do
sleep(5)
end
To use myserver.rb in a production environment, you need to be able to run myserver.rb in the background (this means detach it from the console, fork it in the background, release all directories and file descriptors).
Just create myserver_control.rb like this:
# this is myserver_control.rb
require 'rubygems' # if you use RubyGems
require 'daemons'
Daemons.run('myserver.rb')
And use it like this from the console:
$ ruby myserver_control.rb start
(myserver.rb is now running in the background)
$ ruby myserver_control.rb restart
(...)
$ ruby myserver_control.rb stop
For testing purposes you can even run myserver.rb without forking in the background:
$ ruby myserver_control.rb run
An additional nice feature of Daemons is that you can pass additional arguments to the script that should be daemonized by seperating them by two hyphens:
$ ruby myserver_control.rb start -- --file=anyfile --a_switch another_argument
Layout: suppose you have some code you want to run in the background and control that background process from a script:
# this is your code
# it does nothing really useful at the moment
loop do
sleep(5)
end
To run this code as a daemon create myproc_control.rb like this and include your code:
# this is myproc_control.rb
require 'rubygems' # if you use RubyGems
require 'daemons'
Daemons.run_proc('myproc.rb') do
loop do
sleep(5)
end
end
And use it like this from the console:
$ ruby myproc_control.rb start
(myproc.rb is now running in the background)
$ ruby myproc_control.rb restart
(...)
$ ruby myproc_control.rb stop
For testing purposes you can even run myproc.rb without forking in the background:
$ ruby myproc_control.rb run
Layout: you have an application my_app.rb that wants to run a bunch of server tasks as daemon processes.
# this is my_app.rb
require 'rubygems' # if you use RubyGems
require 'daemons'
task1 = Daemons.call(:multiple => true) do
# first server task
loop {
conn = accept_conn()
serve(conn)
}
end
task2 = Daemons.call do
# second server task
loop {
something_different()
}
end
# the parent process continues to run
# we can even control our tasks, for example stop them
task1.stop
task2.stop
exit
Layout: you have an application my_daemon.rb that wants to run as a daemon (but without the ability to be controlled by daemons via start/stop commands)
# this is my_daemons.rb
require 'rubygems' # if you use RubyGems
require 'daemons'
# Initialize the app while we're not a daemon
init()
# Become a daemon
Daemons.daemonize
# The server loop
loop {
conn = accept_conn()
serve(conn)
}
For further documentation, refer to the module documentation of Daemons.
Download: just go to http://rubyforge.org/projects/daemons/
Installation with RubyGems: $ su # gem install daemons
Installation without RubyGems: $ tar xfz daemons-x.x.x.tar.gz $ cd daemons-x.x.x $ su # ruby setup.rb
For further documentation, refer to the module documentation of Daemons (click on Daemons).
The RDoc documentation is also online at http://daemons.rubyforge.org
Written in 2005-2008 by Thomas Uehlinger mailto:[email protected].
Copyright (c) 2005-2008 Thomas Uehlinger
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
This license does not apply to daemonize.rb, which is was written by Travis Whitton und published under the following license:
The Daemonize extension module is copywrited free software by Travis Whitton [email protected]. You can redistribute it under the terms specified in the COPYING file of the Ruby distribution.