#!/usr/bin/python
import os
import re
import pwd
import grp
import shutil
import stat

ROOT_DIR="/data/www"

# SITES = [(sitename, application_list)]
# application_list = [application_name, (application_name, command, ...)]
# Here, sitename is the name of the site. This folder name should exist below ROOT_DIR and
# is also used below SOCKET_DIR. The site name is also translated to a user and
# group name by replacing dots by dashes and prepending USER_PREFIX and
# GROUP_PREFIX.
#
# application_list specifies the applications to start for this site. These can
# be generic (when only application_name is given), in which case the command
# is looked up in APPLICATIONS using the application_name. For a site-specific
# application, command is the command that should be run. It will be prefixed
# with the site's root dir, if is not an absolute path.

 
SITES=[
	('stderr.nl',             ['php', ('trac', 'applications/trac/trac.fcgi')]),
#	('stdin.nl',              ['php']),
	('stdout.nl',             ['php']),
	('ninniach.nl',           ['php']),
	('evolution-events.nl',   ['php']), #, ('xerxes', 'applications/xerxes/manage.py runfcgi'), ('wipi', 'applications/wipi/wipi.fcgi')]),
#	('stdio.flexvps.nl',      ['php']),
#	('foresightsecurity.nl',  ['php']),
]

# Generic applications that can be run for any site
# Maps application_name to application_command. application_command will be
# prefixed with the site's root dir, if it is not an absolute path.
APPLICATIONS={"php": "/usr/bin/php-cgi"}

# Kill these procs before starting new ones. Only processes of these names that
# are run by the sites in SITES are killed. This is a bit hackish, we should
# really be using pidfiles...
KILL_PROCS=['php-cgi', 'manage.py']

## ABSOLUTE path to the spawn-fcgi binary
SPAWNFCGI="/usr/bin/spawn-fcgi"

## Dir in which to create the UNIX sockets to listen on
SOCKET_DIR="%s/var/fcgi" % (ROOT_DIR)

## number of PHP children to spawn
PHP_FCGI_CHILDREN=2

## maximum number of requests a single PHP process can serve before it is restarted
PHP_FCGI_MAX_REQUESTS=1000

# The user to run as, will be prefixed to the sitename
USER_PREFIX="httpd-"
# The group to run as.
SCRIPT_GROUP="httpd-users"
# The group that should be able to use the sockets created
HTTPD_GROUP="www-data"

# Will be postfixed to the site's root and exported in the PHPRC variable.
PHPRC_DIR="conf"

#### END OF CONFIG ####

for (site, apps) in SITES:
	site_name = re.sub('\.', '-', site)

	## switch to the following user / group
	user_id    = "%s%s" % (USER_PREFIX, site_name)
	
	# Find the site dir
	site_dir   = os.path.join(ROOT_DIR, site)
	socket_dir = os.path.join(SOCKET_DIR, site_name)

	# Pass the site dir to all fastcgi processes
	os.environ['SITE_DIR'] = site_dir

	if not site_dir:
		raise Exception("Site dir does not exist: %s" % (site_dir))
	
	
	# Kill existing processes first
	for procname in KILL_PROCS:
		os.system('killall --user %s %s' % (user_id, procname))

	# Remove old sockets
	if os.path.exists(socket_dir): 
		shutil.rmtree(socket_dir)

	# Create dir for sockets. Make owning group root and set group write
	# permissions, so the mask field in the acl will not block out anything.
	os.makedirs(socket_dir)
	os.chown(socket_dir, pwd.getpwnam(user_id)[2], grp.getgrnam(HTTPD_GROUP)[2])
	#os.chmod(socket_dir, stat.S_IRWXU)
	
	for app in apps:
		# Unpack app tuple or lookup app command in APPLICATIONS
		if isinstance(app, tuple):
			if len(app) == 2:
				(app_name, app_command) = app
			else:
				raise Exception("Wrong number of elements in site tuple: %s", app)
		else:
			app_name = app
			app_command = APPLICATIONS[app_name]
	
		# Prefix with site dir if not an absolute path
		if not os.path.isabs(app_command):
			app_command = os.path.join(site_dir, app_command)

		# Create socket filename
		socket = os.path.join(socket_dir, app_name)

		# Build the command
		# TODO: Wrap this in env to clear up the environment
		spawnfcgi = '%s -s "%s" -u "%s" -g "%s"' % (SPAWNFCGI, socket, user_id, SCRIPT_GROUP)
		fcgiapp = ' -- %s' % (app_command)

		if app_name == 'php':
			os.environ['PHP_FCGI_MAX_REQUESTS'] = str(PHP_FCGI_MAX_REQUESTS)
			phprc = os.path.join(site_dir, PHPRC_DIR, 'php.ini')
			if os.path.exists(phprc):
				#os.environ['PHPRC'] = phprc
				fcgiapp   += ' -c %s' % (phprc)
			spawnfcgi += ' -C %s' % (PHP_FCGI_CHILDREN)


		print spawnfcgi + fcgiapp
		os.system(spawnfcgi + fcgiapp)

		# Ensure www-data can write to the socket :-S
		# Spawn-fcgi explicitely chmods the socket after creation, very
		# annoying
		os.chmod(socket, stat.S_IRWXU | stat.S_IRWXG)