path: root/cobbler/pxegen.py

"""
Builds out filesystem trees/data based on the object tree.
This is the code behind 'cobbler sync'.

Copyright 2006-2008, Red Hat, Inc
Michael DeHaan <mdehaan@redhat.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301  USA
"""

import os
import os.path
import shutil
import time
import sys
import glob
import traceback
import errno
import sub_process
import string

import utils
from cexceptions import *
import templar 

import item_distro
import item_profile
import item_repo
import item_system
import item_image

from utils import _


class PXEGen:
    """
    Handles building out PXE stuff
    """

    def __init__(self,config):
        """
        Constructor
        """
        self.config      = config
        self.api         = config.api
        self.distros     = config.distros()
        self.profiles    = config.profiles()
        self.systems     = config.systems()
        self.settings    = config.settings()
        self.repos       = config.repos()
        self.images      = config.images()
        self.templar     = templar.Templar(config)
        self.bootloc     = utils.tftpboot_location()

    def copy_bootloaders(self):
        """
        Copy bootloaders to the configured tftpboot directory
        NOTE: we support different arch's if defined in
        /etc/cobbler/settings.
        """
        dst = self.bootloc

        # copy syslinux from one of two locations
        try:
            utils.copyfile_pattern('/usr/lib/syslinux/pxelinux.0',   dst, api=self.api)
        except:
            utils.copyfile_pattern('/usr/share/syslinux/pxelinux.0', dst, api=self.api)
 
        # copy memtest only if we find it
        utils.copyfile_pattern('/boot/memtest*', dst, require_match=False, api=self.api)
  
        # copy elilo which we include for IA64 targets
        utils.copyfile_pattern('/var/lib/cobbler/elilo-3.8-ia64.efi', dst, api=self.api)
 
        # copy menu.c32 as the older one has some bugs on certain RHEL
        utils.copyfile_pattern('/var/lib/cobbler/menu.c32', dst, api=self.api)

        # copy yaboot which we include for PowerPC targets
        utils.copyfile_pattern('/var/lib/cobbler/yaboot-1.3.14', dst, api=self.api)

        # copy memdisk as we need it to boot ISOs
        try:
            utils.copyfile_pattern('/usr/lib/syslinux/memdisk',   dst, api=self.api)
        except:
            utils.copyfile_pattern('/usr/share/syslinux/memdisk', dst, api=self.api)


    def copy_distros(self):
        """
        A distro is a kernel and an initrd.  Copy all of them and error
        out if any files are missing.  The conf file was correct if built
        via the CLI or API, though it's possible files have been moved
        since or perhaps they reference NFS directories that are no longer
        mounted.

        NOTE:  this has to be done for both tftp and http methods
        """
        errors = list()
        for d in self.distros:
            # we don't copy the files for windows distros
            if d.breed == "windows":
               continue
            try:
                self.copy_single_distro_files(d)
            except CX, e:
                errors.append(e)
                print e.value

        # FIXME: using logging module so this ends up in cobbler.log?
        if len(errors) > 0:
            raise CX(_("Error(s) encountered while copying distro files"))

    def copy_images(self):
        """
        Like copy_distros except for images.
        """
        errors = list()
        for i in self.images:
            try:
                self.copy_single_image_files(i)
            except CX, e:
                errors.append(e)
                print e.value

        # FIXME: using logging module so this ends up in cobbler.log?
        if len(errors) > 0:
            raise CX(_("Error(s) encountered while copying image files"))

    def copy_single_distro_files(self, d):
        for dirtree in [self.bootloc, self.settings.webdir]: 
            distros = os.path.join(dirtree, "images")
            distro_dir = os.path.join(distros,d.name)
            utils.mkdir(distro_dir)
            kernel = utils.find_kernel(d.kernel) # full path
            initrd = utils.find_initrd(d.initrd) # full path
            if kernel is None or not os.path.isfile(kernel):
                raise CX(_("kernel not found: %(file)s, distro: %(distro)s") % { "file" : d.kernel, "distro" : d.name })
            if initrd is None or not os.path.isfile(initrd):
                raise CX(_("initrd not found: %(file)s, distro: %(distro)s") % { "file" : d.initrd, "distro" : d.name })
            b_kernel = os.path.basename(kernel)
            b_initrd = os.path.basename(initrd)
            allow_symlink=False
            if dirtree == self.settings.webdir:
                allow_symlink=True
            dst1 = os.path.join(distro_dir, b_kernel)
            dst2 = os.path.join(distro_dir, b_initrd)
            utils.linkfile(kernel, dst1, symlink_ok=allow_symlink, api=self.api)
            utils.linkfile(initrd, dst2, symlink_ok=allow_symlink, api=self.api)

    def copy_single_image_files(self, img):
        images_dir = os.path.join(self.bootloc, "images2")
        filename = img.file 
        if not os.path.exists(filename):
            # likely for virtual usage, cannot use
            return
        if not os.path.exists(images_dir):
            os.makedirs(images_dir)
        basename = os.path.basename(img.file)
        newfile = os.path.join(images_dir, img.name)
        utils.linkfile(filename, newfile, api=self.api)
        return True

    def generate_windows_files(self):
        utils.mkdir("/tftpboot/profiles")
        for p in self.profiles:
            distro = p.get_conceptual_parent()
            if distro and distro.breed != "windows":
                continue
            else:
                self.generate_windows_profile_pxe(p)
        utils.mkdir("/tftpboot/systems")
        for s in self.systems:
            profile = s.get_conceptual_parent()
            if profile:
                distro = profile.get_conceptual_parent()
                if distro and distro.breed != "windows":
                    continue
                else:
                    self.generate_windows_system_pxe(s)

    def generate_windows_profile_pxe(self, profile):
        distro = profile.get_conceptual_parent()

        dest_dir = os.path.join("/tftpboot/profiles", profile.name)
        utils.mkdir(dest_dir)

        utils.cabextract(distro.kernel, dest_dir, self.api)

        src_file = os.path.join(dest_dir, "startrom.n12")
        dest_file = os.path.join(dest_dir, "winpxe.0")
        cmd = [ "/bin/sed", "-i", "-e", "s/ntldr/L%s/gi" % profile.random_id, src_file ]
        sub_process.call(cmd, shell=False, close_fds=False)
        os.rename(src_file, dest_file)

        utils.cabextract(distro.initrd, dest_dir, self.api)
       
        src_file = os.path.join(dest_dir, "setupldr.exe")
        dest_file = os.path.join(dest_dir, "NTLDR")
        cmd = [ "/bin/sed", "-i", "-e", "s/winnt\\.sif/w%s.sif/gi" % profile.random_id, src_file ]
        sub_process.call(cmd, shell=False, close_fds=False)
        cmd = [ "/bin/sed", "-i", "-e", "s/ntdetect\\.com/ntd_%s.com/gi" % profile.random_id, src_file ]
        sub_process.call(cmd, shell=False, close_fds=False)
        os.rename(src_file, dest_file)

        src_dir = os.path.dirname(distro.kernel)
        src_file = os.path.join(src_dir, "ntdetect.com")
        file_name = os.path.join(dest_dir, "ntdetect.com")
        utils.copyfile(src_file, file_name, self.api)
 
        template = profile.kickstart
        fd = open(template, "r")
        template_data = fd.read()
        fd.close()

        blended = utils.blender(self.api, True, profile)
        blended['next_server'] = self.settings.next_server
        # this is a workaround for a dumb bug in cheetah...
        # a backslash before a variable is always treated as 
        # escaping the $, so things are not rendered correctly.
        # The only option is to use another variable for
        # backslashes when leading another variable. i.e.:
        # \\$variable
        blended['bsp'] = '\\'

        data = self.templar.render(template_data, blended, None)

        # write .sif to /tftpboot/profiles/$name/winnt.sif
        file_name = os.path.join(dest_dir, "winnt.sif")
        fd = open(file_name, "w")
        fd.write(data)
        fd.close()

        return True

    def generate_windows_system_pxe(self, system):
        profile = system.get_conceptual_parent()
        if not profile:
            return False

        distro = profile.get_conceptual_parent()

        dest_dir = os.path.join("/tftpboot/systems", system.name)
        utils.mkdir(dest_dir)

        utils.cabextract(distro.kernel, dest_dir, self.api)

        src_file = os.path.join(dest_dir, "startrom.n12")
        dest_file = os.path.join(dest_dir, "winpxe.0")
        cmd = [ "/bin/sed", "-i", "-e", "s/ntldr/L%s/gi" % system.random_id, src_file ]
        sub_process.call(cmd, shell=False, close_fds=False)
        os.rename(src_file, dest_file)

        utils.cabextract(distro.initrd, dest_dir, self.api)

        src_file = os.path.join(dest_dir, "setupldr.exe")
        dest_file = os.path.join(dest_dir, "NTLDR")
        cmd = [ "/bin/sed", "-i", "-e", "s/winnt\\.sif/w%s.sif/gi" % system.random_id, src_file ]
        sub_process.call(cmd, shell=False, close_fds=False)
        cmd = [ "/bin/sed", "-i", "-e", "s/ntdetect\\.com/ntd_%s.com/gi" % system.random_id, src_file ]
        sub_process.call(cmd, shell=False, close_fds=False)
        os.rename(src_file, dest_file)

        src_dir = os.path.dirname(distro.kernel)
        src_file = os.path.join(src_dir, "ntdetect.com")
        file_name = os.path.join(dest_dir, "ntdetect.com")
        utils.copyfile(src_file, file_name, self.api)

        template = system.kickstart
        if template == "<<inherit>>":
            template = profile.kickstart

        fd = open(template, "r")
        template_data = fd.read()
        fd.close()

        blended = utils.blender(self.api, True, system)
        blended['next_server'] = self.settings.next_server
        # this is a workaround for a dumb bug in cheetah...
        # a backslash before a variable is always treated as
        # escaping the $, so things are not rendered correctly.
        # The only option is to use another variable for
        # backslashes when leading another variable. i.e.:
        # \\$variable
        blended['bsp'] = '\\'

        data = self.templar.render(template_data, blended, None)

        # write .sif to /tftpboot/systems/$name/winnt.sif
        file_name = os.path.join(dest_dir, "winnt.sif")
        fd = open(file_name, "w")
        fd.write(data)
        fd.close()

        return True

    def write_all_system_files(self,system):

        profile = system.get_conceptual_parent()
        if profile is None:
            raise CX(_("system %(system)s references a missing profile %(profile)s") % { "system" : system.name, "profile" : system.profile})
        distro = profile.get_conceptual_parent()
        image_based = False
        image = None
        if distro is None:
            if profile.COLLECTION_TYPE == "profile":
               raise CX(_("profile %(profile)s references a missing distro %(distro)s") % { "profile" : system.profile, "distro" : profile.distro})
            else:
               image_based = True
               image = profile

        # this used to just generate a single PXE config file, but now must
        # generate one record for each described NIC ...
 
        for (name,interface) in system.interfaces.iteritems():

            ip = interface["ip_address"]

            f1 = utils.get_config_filename(system,interface=name)

            if image_based:
                working_arch = image.arch
            else:
                working_arch = distro.arch

            if working_arch is None or working_arch == "":
                working_arch = "x86"

            # for tftp only ...
            if working_arch in [ "i386", "x86", "x86_64", "standard"]:
                # pxelinux wants a file named $name under pxelinux.cfg
                f2 = os.path.join(self.bootloc, "pxelinux.cfg", f1)
            elif working_arch == "ia64":
                # elilo expects files to be named "$name.conf" in the root
                # and can not do files based on the MAC address
                if ip is not None and ip != "":
                    print _("Warning: Itanium system object (%s) needs an IP address to PXE") % system.name

                filename = "%s.conf" % utils.get_config_filename(system,interface=name)
                f2 = os.path.join(self.bootloc, filename)
            elif working_arch.startswith("ppc"):
                # Determine filename for system-specific yaboot.conf
                filename = "%s" % utils.get_config_filename(system, interface=name).lower()
                f2 = os.path.join(self.bootloc, "etc", filename)

                # Link to the yaboot binary
                f3 = os.path.join(self.bootloc, "ppc", filename)
                if os.path.lexists(f3):
                    utils.rmfile(f3)
                os.symlink("../yaboot-1.3.14", f3)

            elif working_arch == "s390x":
                filename = "%s" % utils.get_config_filename(system,interface=name)
                f2 = os.path.join(self.bootloc, "s390x", filename)
            else:
                continue 

            if system.is_management_supported():
                if not image_based:
                    self.write_pxe_file(f2,system,profile,distro,working_arch)
                else:
                    self.write_pxe_file(f2,system,None,None,working_arch,image=profile)
            else:
                # ensure the file doesn't exist
                utils.rmfile(f2)

    def make_pxe_menu(self):
        self.make_s390_pseudo_pxe_menu()
        self.make_actual_pxe_menu() 

    def make_s390_pseudo_pxe_menu(self):
        s390path = os.path.join(self.bootloc, "s390x")
        if not os.path.exists(s390path):
            utils.mkdir(s390path)
        profile_list = [profile for profile in self.profiles]
        image_list = [image for image in self.images]
        def sort_name(a,b):
           return cmp(a.name,b.name)
        profile_list.sort(sort_name)
        image_list.sort(sort_name)
        listfile = open(os.path.join(s390path, "profile_list"),"w+")
        for profile in profile_list:
            distro = profile.get_conceptual_parent()
            if distro is None:
                raise CX(_("profile is missing distribution: %s, %s") % (profile.name, profile.distro))
            if distro.arch == "s390x":
                listfile.write("%s\n" % profile.name)
            f2 = os.path.join(self.bootloc, "s390x", profile.name)
            self.write_pxe_file(f2,None,profile,distro,distro.arch)
        listfile2 = open(os.path.join(s390path, "image_list"),"w+")
        for image in image_list:
            if os.path.exists(image.file):
                listfile2.write("%s\n" % image.name)
            f2 = os.path.join(self.bootloc, "s390x", image.name)
            self.write_pxe_file(f2,None,None,None,image.arch,image=image)
        listfile.close()
        listfile2.close()

    def make_actual_pxe_menu(self):
        # only do this if there is NOT a system named default.
        default = self.systems.find(name="default")
        if default is not None:
            return
        
        fname = os.path.join(self.bootloc, "pxelinux.cfg", "default")

        # read the default template file
        template_src = open(os.path.join(self.settings.pxe_template_dir,"pxedefault.template"))
        template_data = template_src.read()

        # sort the profiles
        profile_list = [profile for profile in self.profiles]
        def sort_name(a,b):
           return cmp(a.name,b.name)
        profile_list.sort(sort_name)

        # sort the images
        image_list = [image for image in self.images]
        image_list.sort(sort_name)

        # build out the menu entries
        pxe_menu_items = ""
        for profile in profile_list:
            if not profile.enable_menu:
               # This profile has been excluded from the menu
               continue
            distro = profile.get_conceptual_parent()
            # xen distros can be ruled out as they won't boot
            if distro.name.find("-xen") != -1:
                # can't PXE Xen
                continue
            contents = self.write_pxe_file(None,None,profile,distro,distro.arch,include_header=False)
            if contents is not None:
                pxe_menu_items = pxe_menu_items + contents + "\n"

        # image names towards the bottom
        for image in image_list:
            if os.path.exists(image.file):
                contents = self.write_pxe_file(None,None,None,None,image.arch,image=image)
                if contents is not None:
                    pxe_menu_items = pxe_menu_items + contents + "\n"

        # if we have any memtest files in images, make entries for them
        # after we list the profiles
        memtests = glob.glob(self.bootloc + "/images/memtest*")
        if len(memtests) > 0:
            pxe_menu_items = pxe_menu_items + "\n\n"
            for memtest in glob.glob(self.bootloc + '/images/memtest*'):
                base = os.path.basename(memtest)
                contents = self.write_memtest_pxe("/images/%s" % base)
                pxe_menu_items = pxe_menu_items + contents + "\n"
              
        # save the template.
        metadata = { "pxe_menu_items" : pxe_menu_items }
        outfile = os.path.join(self.bootloc, "pxelinux.cfg", "default")
        self.templar.render(template_data, metadata, outfile, None)
        template_src.close()

    def write_memtest_pxe(self,filename):
        """
        Write a configuration file for memtest
        """

        # FIXME: this should be handled via "cobbler image add" now that it is available,
        # though it would be nice if there was a less-manual way to add those as images.

        # just some random variables
        template = None
        metadata = {}
        buffer = ""

        template = os.path.join(self.settings.pxe_template_dir,"pxeprofile.template")

        # store variables for templating
        metadata["menu_label"] = "MENU LABEL %s" % os.path.basename(filename)
        metadata["profile_name"] = os.path.basename(filename)
        metadata["kernel_path"] = "/images/%s" % os.path.basename(filename)
        metadata["initrd_path"] = ""
        metadata["append_line"] = ""

        # get the template
        template_fh = open(template)
        template_data = template_fh.read()
        template_fh.close()

        # return results
        buffer = self.templar.render(template_data, metadata, None)
        return buffer


    def write_pxe_file(self,filename,system,profile,distro,arch,image=None,include_header=True):
        """
        Write a configuration file for the boot loader(s).
        More system-specific configuration may come in later, if so
        that would appear inside the system object in api.py

        NOTE: relevant to tftp and pseudo-PXE (s390) only

        ia64 is mostly the same as syslinux stuff, s390 is a bit
        short-circuited and simpler.  All of it goes through the
        templating engine, see the templates in /etc/cobbler for
        more details
        """

        if image and not os.path.exists(image.file):
            return None  # nfs:// URLs or something, can't use for TFTP

        # ---
        # just some random variables
        template = None
        metadata = {}
        buffer = ""

        # ---
        kickstart_path = None
        kernel_path = None
        initrd_path = None

        if image is None: 
            # profile or system+profile based, not image based, or system+image based

            if distro is not None and distro.breed == "windows":
                if system:
                    kernel_path = "systems/%s/winpxe.0" % system.name
                elif profile:
                    kernel_path = "profiles/%s/winpxe.0" % profile.name
            else:
                kernel_path = os.path.join("/images",distro.name,os.path.basename(distro.kernel))
                initrd_path = os.path.join("/images",distro.name,os.path.basename(distro.initrd))
        
            # Find the kickstart if we inherit from another profile
            kickstart_path = utils.blender(self.api, True, profile)["kickstart"]
        else:
            if image.image_type == "direct":
                kernel_path = os.path.join("/images2",image.name)
            elif image.image_type == "memdisk":
                kernel_path = "/memdisk"
                initrd_path = os.path.join("/images2",image.name)
            else:
                # CD-ROM ISO or virt-clone image? We can't PXE boot it.
                kernel_path = None
                initrd_path = None
        # ---
        # choose a template
        if system:
            if system.netboot_enabled:
                if distro is not None and distro.breed == "windows":
                    template = os.path.join(self.settings.pxe_template_dir,"pxesystem_win.template")
                else:
                    template = os.path.join(self.settings.pxe_template_dir,"pxesystem.template")
    
                if arch == "s390x":
                    template = os.path.join(self.settings.pxe_template_dir,"pxesystem_s390x.template")
                elif arch == "ia64":
                    template = os.path.join(self.settings.pxe_template_dir,"pxesystem_ia64.template")
                elif arch.startswith("ppc"):
                    template = os.path.join(self.settings.pxe_template_dir,"pxesystem_ppc.template")
            else:
                # local booting on ppc requires removing the system-specific dhcpd.conf filename
                if arch is not None and arch.startswith("ppc"):
                    # Disable yaboot network booting for all interfaces on the system
                    for (name,interface) in system.interfaces.iteritems():

                        # Determine filename for system-specific yaboot.conf
                        filename = "%s" % utils.get_config_filename(system, interface=name).lower()

                        # Remove symlink to the yaboot binary
                        f3 = os.path.join(self.bootloc, "ppc", filename)
                        if os.path.lexists(f3):
                            utils.rmfile(f3)

                        # Remove the interface-specific config file
                        f3 = os.path.join(self.bootloc, "etc", filename)
                        if os.path.lexists(f3):
                            utils.rmfile(f3)

                    # Yaboot/OF doesn't support booting locally once you've
                    # booted off the network, so nothing left to do
                    return None
                else:
                    template = os.path.join(self.settings.pxe_template_dir,"pxelocal.template")
        else:
            if distro is not None and distro.breed == "windows":
                template = os.path.join(self.settings.pxe_template_dir,"pxeprofile_win.template")
            else:
                template = os.path.join(self.settings.pxe_template_dir,"pxeprofile.template")


        # now build the kernel command line
        if system is not None:
            blended = utils.blender(self.api, True, system)
        elif profile is not None:
            blended = utils.blender(self.api, True, profile)
        else:
            blended = utils.blender(self.api, True, image)
        kopts = blended.get("kernel_options","")

        # generate the append line
        hkopts = utils.hash_to_string(kopts)
        if initrd_path and (not arch or arch not in ["ia64", "ppc", "ppc64"]):
            append_line = "append initrd=%s %s" % (initrd_path, hkopts)
        else:
            append_line = "append %s" % hkopts

        if len(append_line) >= 255 + len("append "):
            print _("warning: kernel option length exceeds 255")

        # kickstart path rewriting (get URLs for local files)
        if kickstart_path is not None and kickstart_path != "":

            if system is not None and kickstart_path.startswith("/"):
                kickstart_path = "http://%s/cblr/svc/op/ks/system/%s" % (blended["http_server"], system.name)
            elif kickstart_path.startswith("/") or kickstart_path.find("/cobbler/kickstarts/") != -1:
                kickstart_path = "http://%s/cblr/svc/op/ks/profile/%s" % (blended["http_server"], profile.name)

            if distro.breed is None or distro.breed == "redhat":
                append_line = "%s ks=%s" % (append_line, kickstart_path)
            elif distro.breed == "suse":
                append_line = "%s autoyast=%s" % (append_line, kickstart_path)
            elif distro.breed == "debian":
                append_line = "%s auto=true url=%s" % (append_line, kickstart_path)
            # interface=bootif causes a failure
            #    append_line = append_line.replace("ksdevice","interface")

        if arch in ["s390x", "ppc", "ppc64"]:
            # remove the prefix "append"
            append_line = append_line[7:]

        # store variables for templating
        metadata["menu_label"] = ""
        if profile:
            if not arch in [ "ia64", "ppc", "ppc64", "s390x" ]:
                metadata["menu_label"] = "MENU LABEL %s" % profile.name
                metadata["profile_name"] = profile.name
        elif image:
            metadata["menu_label"] = "MENU LABEL %s" % image.name
            metadata["profile_name"] = image.name

        if system:
            metadata["system_name"] = system.name

        if kernel_path is not None:
            metadata["kernel_path"] = kernel_path
        if initrd_path is not None:
            metadata["initrd_path"] = initrd_path

        metadata["append_line"] = append_line

        # get the template
        if kernel_path is not None:
            template_fh = open(template)
            template_data = template_fh.read()
            template_fh.close()
        else:
            # this is something we can't PXE boot
            template_data = "\n"        

        # save file and/or return results, depending on how called.
        buffer = self.templar.render(template_data, metadata, None)
        if filename is not None:
            fd = open(filename, "w")
            fd.write(buffer)
            fd.close()
        return buffer

    def write_templates(self,obj,write_file=False,path=None):
        """
        A semi-generic function that will take an object
        with a template_files hash {source:destiation}, and 
        generate a rendered file.  The write_file option 
        allows for generating of the rendered output without
        actually creating any files.

        The return value is a hash of the destination file
        names (after variable substitution is done) and the
        data in the file.
        """

        results = {}

        try:
           templates = obj.template_files
        except:
           return results

        blended = utils.blender(self.api, False, obj)
        ksmeta = blended.get("ks_meta",{})
        del blended["ks_meta"]
        blended.update(ksmeta) # make available at top level

        (success, templates) = utils.input_string_or_hash(templates)

        if not success:
            return results


        for template in templates.keys():
            dest = templates[template]
            
            # Run the source and destination files through 
            # templar first to allow for variables in the path 
            template = self.templar.render(template, blended, None).strip()
            dest     = self.templar.render(dest, blended, None).strip()
            # Get the path for the destination output
            dest_dir = os.path.dirname(dest)

            # If we're looking for a single template, skip if this ones
            # destination is not it.
            if not path is None and path != dest:
               continue

            # If we are writing output to a file, force all templated 
            # configs into the rendered directory to ensure that a user 
            # granted cobbler privileges via sudo can't overwrite 
            # arbitrary system files (This also makes cleanup easier).
            if os.path.isabs(dest_dir):
               if write_file:
                   raise CX(_(" warning: template destination (%s) is an absolute path, skipping.") % dest_dir)
                   continue
            else:
                dest_dir = os.path.join(self.settings.webdir, "rendered", dest_dir)
                dest = os.path.join(dest_dir, os.path.basename(dest))
                if not os.path.exists(dest_dir):
                    utils.mkdir(dest_dir)

            # Check for problems
            if not os.path.exists(template):
               raise CX(_("template source %s does not exist") % template)
               continue
            elif write_file and not os.path.isdir(dest_dir):
               raise CX(_("template destination (%s) is invalid") % dest_dir)
               continue
            elif write_file and os.path.exists(dest): 
               raise CX(_("template destination (%s) already exists") % dest)
               continue
            elif write_file and os.path.isdir(dest):
               raise CX(_("template destination (%s) is a directory") % dest)
               continue
            elif template == "" or dest == "": 
               raise CX(_("either the template source or destination was blank (unknown variable used?)") % dest)
               continue
            
            template_fh = open(template)
            template_data = template_fh.read()
            template_fh.close()

            buffer = self.templar.render(template_data, blended, None)
            results[dest] = buffer

            if write_file:
                fd = open(dest, "w")
                fd.write(buffer)
                fd.close()

            # print _(" template %s created ok") % dest

        return results


    def write_tftpd_rules(self,write_file=False):
        buffer = ""
        template = "/etc/cobbler/tftpd-rules.template"
        rules_dst = self.settings.tftpd_rules
        ldr_rule_line = "re\t^L$random_id\t\t%s/$name/NTLDR\n"
        sif_rule_line = "re\t/.*w$random_id\\.sif\t%s/$name/winnt.sif\n"
        ntd_rule_line = "re\t/.*ntd_$random_id\.com\t%s/$name/ntdetect.com\n"

        fd = open(template, "r")
        buffer = fd.read()
        fd.close()

        buffer += "\n"

        for profile in self.profiles:
            try:
                effective_distro = profile.get_conceptual_parent()
                if effective_distro.breed != "windows":
                    continue
            except:
                print _(" warning: could not determine distro for profile %s") % profile.name
                continue
            try:
                blended = utils.blender(self.api, False, profile)
                buffer += self.templar.render(ldr_rule_line % "profiles", blended, None)
                buffer += self.templar.render(sif_rule_line % "profiles", blended, None)
                buffer += self.templar.render(ntd_rule_line % "profiles", blended, None)
            except:
                print _(" warning: could not generate tftpd rules for profile %s") % profile.name

        for system in self.systems:
            try:
                effective_distro = system.get_conceptual_parent().get_conceptual_parent()
                if effective_distro.breed != "windows":
                    continue
            except:
                print _(" warning: could not determine distro for system %s") % system.name
                continue
            try:
                blended = utils.blender(self.api, False, system)
                buffer += self.templar.render(ldr_rule_line % "systems", blended, None)
                buffer += self.templar.render(sif_rule_line % "systems", blended, None)
                buffer += self.templar.render(ntd_rule_line % "systems", blended, None)
            except: 
                print _(" warning: could not generate tftpd rules for system %s") % system.name

        if write_file:
            fd = open(rules_dst, "w")
            fd.write(buffer)
            fd.close()

        return buffer