cryptonas/bin/CryptoBoxWebserver.py

#!/usr/bin/python2.4
import os
import WebInterfaceSites
from CryptoBoxExceptions import *
import sys

try:
	import cherrypy
except: 
	print "Could not import the cherrypy module! Try 'apt-get install python-cherrypy'."
	sys.exit(1)



## TODO: it should be possible to override this via commandline arguments
PID_FILE = '/var/run/cryptobox/webserver.pid'

class CryptoBoxWebserver:
	'''this class starts the cherryp webserver and serves the single sites'''

	def __init__(self):
		try:
			cherrypy.root = WebInterfaceSites.WebInterfaceSites()
		except (CBConfigError,CBEnvironmentError), errMsg:
			sys.stderr.write("The CryptoBox is misconfigured - please fix it!\n")
			sys.stderr.write("%s\n" % str(errMsg))
			sys.exit(1)
		#expose static content:
		#I currently have no idea how to cleanly extract the stylesheet path from 
		#the config object without an extra CryptoBox.CryptoBoxProps instance.
		#perhaps put config handling into a separate class in CryptoBox.py?
		#
		# the following manual mapping is necessary, as we may not use relative
		# paths in the config file
		cherrypy.config.configMap.update({ 
			"/cryptobox-misc": { 
					"staticFilter.on" : True, 
					"staticFilter.dir": os.path.abspath("/usr/share/cryptobox/html" )}
			})
		
	def start(self):
		# just use this config, when we're started directly
		cherrypy.config.update(file = "/etc/cryptobox/cryptoboxwebserver.conf")
		cherrypy.server.start()


def fork_to_background():
	## this is just copy'n'pasted from http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/278731
	## check the original for exhaustive comments
	try:
		pid = os.fork()
	except OSError, errMsg:
		sys.stderr.write("Failed to fork cryptobox daemon process!\n")
		sys.stderr.write("%s\n" % errMsg)
		sys.exit(1)
	if pid == 0:	# the first child
		os.setsid()
		try:
			pid = os.fork()
		except OSError, errMsg:
			sys.stderr.write("Failed to fork second cryptobox daemon process!\n")
			sys.stderr.write("%s\n" % errMsg)
			sys.exit(1)
		if pid == 0:	# the second child
			os.chdir(os.path.sep)
			os.umask(0)
		else:
			os._exit(0)
	else:
		os._exit(0)
	import resource		# Resource usage information.
	maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
	if (maxfd == resource.RLIM_INFINITY):
		maxfd = 1024
	for fd in range(0, maxfd):
		try:
			os.close(fd)
		except OSError:		# ERROR, fd wasn't open to begin with (ignored)
			pass
	os.open(os.devnull, os.O_RDWR)		# standard input (0)
	os.dup2(0, 1)			# standard output (1)
	os.dup2(0, 2)			# standard error (2)


def write_pid_file(pid_file):
	try:
		pidf = open(pid_file,"w")
		pidf.write(str(os.getpid()))
		pidf.close()
	except (IOError, OSError), errMsg:
		sys.stderr.write("Failed to write pid file (%s): %s\n" % (pid_file, errMsg))
		## it is just a warning - no need to break


if __name__ == "__main__":
	## TODO: add some argument checking: configFile, daemonMode, ...
	cbw = CryptoBoxWebserver()
	## run the webserver as a daemon process
	fork_to_background()
	## write pid file
	write_pid_file(PID_FILE)
	try:
		cbw.start()
	except Exceptions, errMsg:
		sys.stderr.write("Failed to start the CryptoBox webserver!\n")
		sys.stderr.write("%s\n" % str(errMsg))
		sys.stderr.write("Check the log file for details.\n")
		sys.exit(1)
	sys.exit(0)