source: trunk/packages/sipb-xen-console/files/usr/bin/invirt-consolefs @ 1200

#!/usr/bin/python

import routefs
from routes import Mapper

from syslog import *
from time import time

import os
import errno

from invirt.config import structs as config
from invirt import database

realpath = "/home/machines/"

class ConsoleFS(routefs.RouteFS):
        """
        ConsoleFS creates a series of subdirectories each mirroring the same real
        directory, except for a single file - the .k5login - which is dynamically
        generated for each subdirectory
        """
        
        def __init__(self, *args, **kw):
                """Initialize the filesystem and set it to allow_other access besides
                the user who mounts the filesystem (i.e. root)
                """
                super(ConsoleFS, self).__init__(*args, **kw)
                self.lasttime = time()
                self.fuse_args.add("allow_other", True)
                
                openlog('invirt-consolefs ', LOG_PID, LOG_DAEMON)
                
                syslog(LOG_DEBUG, 'Init complete.')

        def make_map(self):
                m = Mapper()
                m.connect('', controller='getMachines')
                m.connect(':machine', controller='getMirror')
                m.connect(':machine/.k5login', controller='getK5login')
                m.connect(':machine/*(path)', controller='getMirror')
                return m
        
        def getMachines(self, **kw):
                """Get the list of VMs in the database, clearing the cache if it's 
                older than 15 seconds"""
                if time() - self.lasttime > 15:
                        self.lasttime = time()
                        database.clear_cache()
                return [machine.name for machine in database.Machine.query()]
        
        def getMirror(self, machine, path='', **kw):
                """Translate the path into its realpath equivalent, and return that
                """
                real = realpath + path
                if os.path.isdir(real):
                        # The list is converted to a set so that we can handle the case 
                        # where there is already a .k5login in the realpath gracefully    
                        return routefs.Directory(set(os.listdir(real) + ['.k5login']))
                elif os.path.islink(real):
                        return routefs.Symlink(os.readlink(real))
                elif os.path.isfile(real):
                        return open(real).read()
                else:
                        return -errno.EINVAL
        
        def getK5login(self, machine, **kw):
                """Build the ACL for a machine and turn it into a .k5login file
                """
                machine = database.Machine.query().filter_by(name=machine).one()
                users = [acl.user for acl in machine.acl]
                return "\n".join(map(self.userToPrinc, users) + [''])
        
        def mirrorPath(self, path):
                """Translate a virtual path to its real path counterpart"""
                return realpath + "/".join(getParts(path)[1:])
        
        def userToPrinc(self, user):
                """Convert Kerberos v4-style names to v5-style and append a default
                realm if none is specified
                """
                if '@' in user:
                        (princ, realm) = user.split('@')
                else:
                        princ = user
                        realm = config.authn[0].realm
                
                return princ.replace('.', '/') + '@' + realm

if __name__ == '__main__':
        database.connect()
        routefs.main(ConsoleFS)