FreebsdRcIntegration

= Integration with FreeBSD's rc.conf / rc.d system =

This page describes how to start a cherrypy site using its built-in HTTP server and '''cherryd''' in such a way that it integrates nicely with FreeBSD's rc system.  FreeBSD uses a text file '''/etc/rc.conf''' in combination with a set of scripts in '''/usr/local/etc/rc.d''' to start local daemons.


I set out to achieve the following:
 * automatically start the site when the server boots
 * being able to stop, start and restart the site
 * no need to install a third-party web server like Apache
 * compatible with FreeBSD's rc system and /var/run pidfiles
 * uses '''cherryd''' for daemonization
 * able to use standard port 80

In the following example I have my site defined in '''chsite.py''' and '''chsite.conf''', which both reside in '''/www'''.

First, make sure the cherryd script itself is executable. In a standard install of cherrypy under FreeBSD:

{{{
chmod a+x /usr/local/lib/python2.5/site-packages/cherrypy/cherryd
}}}

Include the following lines in /etc/rc.conf:

{{{
cherryd_enable="YES"
cherryd_wwwdir="/www"
cherryd_flags="-c chsite.conf -i chsite"
}}}

Put the following script as '''cherryd''' in '''/usr/local/etc/rc.d''', and don't forget to make it executable:

{{{
#!sh
#!/bin/sh
#
# cherryd for FreeBSD 7.0 rc.d usage, by Michiel Overtoom, motoom@xs4all.nl
# based on http://www.djangosnippets.org/snippets/1050/ by David Blewett
#

# PROVIDE: cherryd
# REQUIRE: LOGIN
# KEYWORD: shutdown

# Add these lines to /etc/rc.conf:
#
#  cherryd_enable="YES"
#  cherryd_wwwdir="/www" # where the site .py and .conf files are
#  cherryd_flags="-c CONFIG -i IMPORTS"  # specify config file(s) and imports to use
#
# Make sure the cherryd script is chmodded as executable.
#
# Before playing interactively with this script and not having added the
# config lines to rc.conf yet, you might want to do: setenv cherryd_enable YES

. /etc/rc.subr

# On FreeBSD 7, the default location for python is /usr/local/bin,
# but during boot /usr/local/bin isn't in the PATH yet.
# The cherryd script uses the following shebang line: #!/usr/bin/env python
# to make that shebang work, we have to add /usr/local/bin to the PATH.
PATH="$PATH:/usr/local/bin"

name="cherryd"
rcvar=`set_rcvar`
pidfile="/var/run/${name}.pid"

command_interpreter="python"
command="/usr/local/lib/python2.5/site-packages/cherrypy/${name}"
command_args="-d -p $pidfile ${cherryd_flags}"

start_cmd="echo \"Starting ${name}.\"; cd ${cherryd_wwwdir}; ${command} ${command_args}"

load_rc_config $name
run_rc_command "$1"
}}}


After these changes, the site should start automatically when the machine is restarted. To stop, start, restart the site you'd use the commands:

{{{
# /usr/local/etc/rc.d/cherryd stop
# /usr/local/etc/rc.d/cherryd start
# /usr/local/etc/rc.d/cherryd restart
}}}


See also [wiki:daemonization].

Written by Michiel Overtoom, december 2008, mailto:motoom@xs4all.nl