LUNCH(1)							   User Commands							  LUNCH(1)

NAME

       lunch - Distributed process launcher

SYNOPSIS

       lunch [config file] [options]

DESCRIPTION

       Lunch  is a distributed process launcher for GNU/Linux. The Lunch master launches lunch-slave processes through an encrypted SSH session if
       on a remote host. Those slave processes can in turn launch the desired commands on-demand.

OPTIONS

       --version
	      show program's version number and exit

       -h, --help
	      show this help message and exit

       -f CONFIG_FILE, --config-file=CONFIG_FILE
	      Specifies the python config file. You can also simply specify the config file as the first argument.

       -l LOGGING_DIRECTORY, --logging-directory=LOGGING_DIRECTORY
	      Specifies the logging and pidfile directory for the master. Default is /var/tmp/lunch

       -q, --log-to-file
	      Enables logging master infos to file and disables logging to standard output.

       -g, --graphical
	      Enables the graphical user interface.

       -v, --verbose
	      Makes the logging output verbose.

       -d, --debug
	      Makes the logging output very verbose.

       -k, --kill
	      Kills another lunch master that uses the same config file and logging directory. Exits once it's done.

EXAMPLES

       See the examples directory for examples. On a Debian or Ubuntu system, they should located in the /usr/share/doc/lunch/examples/ directory.

       Here is the simplest example possible for the contents of a ~/.lunchrc file. It tells Lunch to call only one command, called "xeyes".

	 add_command("xeyes")

       If you add more calls to add_command in this file, it will add more processes to be launched by Lunch. The add_command is the Python  func-
       tion  you need to call from your Lunch configuration file in order to add commands to be called by Lunch. If you add more than one command,
       they will be called in the order you add them in the file.

       Here is a more complex example of a configuration file. It creates three processes, with dependencies between processes.

	 add_command("xeyes", identifier="xeyes")
	 add_command("xlogo", depends=["xeyes"])
	 add_command("xclock", depends=["xeyes", "xlogo"])

       The configuration file above will first start xeyes, and next xlogo, and finally xclock. If  xeyes  quits,  all	three  processes  will	be
       stopped	and restarted. If the xlogo process quits, the xclock will be stopped and restarted again when the xlogo is running. The "depends"
       keyword argument of the "add_command" function needs a list of strings as argument. Those string must match the "identifier" keyword  argu-
       ment of an already added command.

       In  the	next  example,	we use SSH to launch processes on a remote host. Note that the lunch-slave script must be installed on each of the
       hosts on which to launch child processes.

	 add_command("xeyes")
	 add_command("xeyes", user="johndoe", host="example.org")

       It will create a process tree such as this one :

       lunch_______________lunch-slave____xeyes
	       |____ssh____lunch-slave____xeyes

       The next one is a command that is run only once.

	 add_command("ls -l", identifier="listing...", respawn=False)

       If, for some reason, it is easier for you to specify the host name for every command you add,  even  for  the  local  host,  you  can  call
       "add_local_address" with the master's IP as an argument.

	 add_local_address("192.168.1.2")
	 # We will not use SSH for this one,
	 # since we just added its host using the
	 # "add_local_address" function.
	 add_command("xeyes",
	   identifier="local_xeyes",
	   user="johndoe", host="192.168.0.2")
	 # We will use SSH for the next one,
	 # since its host is not set as being the local host.
	 add_command("xeyes -geometry 300x400",
	   identifier="remote_xeyes",
	   user="johndoe", host="example.org")

OPERATION

       The  lunch  executable  is  called  the lunch master. The lunch-slave executable is called the lunch slave. If run as a master, it launches
       slaves. The slaves are responsible for launching child processes. The master launches slaves (via SSH or not) which, in turn, launch  child
       processes.

       The  Lunch configuration file can be provided as a first argument to the lunch executable. If not given, the Lunch master will look for the
       ~/.lunchrc file. If not found, lunch will print an error and exit. The lunch config file is written in the Python programming language, and
       must call the add_command function.

       The  process ID of the master is written to a file located in /var/tmp/lunch/master*.pid, where * varies depending on the lunch config file
       used to configure the master.  Here is how to kill every lunch master on your system :

	 for f in /var/tmp/lunch/master-*.pid; do kill -15 $(cat $f); done

GRAPHICAL USER INTERFACE

       When invoked with the --graphical option, (-g) the lunch master shows a graphical user interface displaying  the  state	of  every  managed
       process. When this window is closed, the lunch master exits and kills all its children processes.

SSH KEYS MANAGEMENT

       If  using  for more than one host, lunch needs a SSH server installed on each remote computer. It is also needed that the public SSH key of
       your user on the master computer must be installed on every slave computer. Here is a summary of the steps to do to create  a  SSH  key	on
       your master computer, and send your public key on each slave computer.

	 $ mkdir -p ~/.ssh
	 $ chmod 700 ~/.ssh
	 $ ssh-keygen -f ~/.ssh/id_rsa -t rsa

       Next, for each slave host, do:

	 $ ssh-copy-id <username>@<host>
	 $ ssh username@host 'echo Hello'

       The latter command should display "Hello" when issued.

       If you start lunch via SSH, and launch from there commands other hosts, you must first make sure that the ssh-agent is running and that you
       have unlocked your private SSH key. It can be done like this:

	 $ ssh-agent bash
	 $ ssh-add

HISTORY

       2010 - Ported from multiprocessing to Twisted

       2009 - Written by Alexandre Quessy <alexandre@quessy.net> with contributions from Simon Piette <simonp@sat.qc.ca>

REPORTING BUGS

       See http://svn.sat.qc.ca/trac/lunch for help and documentation.

SEE ALSO

       lunch-slave (1)

lunch 0.4.0							   January 2011 							  LUNCH(1)