Synnefo » snf-image-creator

#!/usr/bin/env python

# Copyright 2012 GRNET S.A. All rights reserved.

#

# Redistribution and use in source and binary forms, with or

# without modification, are permitted provided that the following

# conditions are met:

#

#   1. Redistributions of source code must retain the above

#      copyright notice, this list of conditions and the following

#      disclaimer.

#

#   2. Redistributions in binary form must reproduce the above

#      copyright notice, this list of conditions and the following

#      disclaimer in the documentation and/or other materials

#      provided with the distribution.

#

# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS

# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR

# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF

# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED

# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN

# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

# POSSIBILITY OF SUCH DAMAGE.

#

# The views and conclusions contained in the software and

# documentation are those of the authors and should not be

# interpreted as representing official policies, either expressed

# or implied, of GRNET S.A.

import dialog

import sys

import os

import textwrap

import signal

import StringIO

import optparse

from image_creator import __version__ as version

from image_creator.util import FatalError, MD5

from image_creator.output.dialog import GaugeOutput, InfoBoxOutput

from image_creator.disk import Disk

from image_creator.os_type import os_cls

from image_creator.kamaki_wrapper import Kamaki, ClientError

from image_creator.help import get_help_file

from image_creator.dialog_wizard import wizard

MSGBOX_WIDTH = 60

YESNO_WIDTH = 50

MENU_WIDTH = 70

INPUTBOX_WIDTH = 70

CHECKBOX_WIDTH = 70

HELP_WIDTH = 70

INFOBOX_WIDTH = 70

CONFIGURATION_TASKS = [

    ("Partition table manipulation", ["FixPartitionTable"],

        ["linux", "windows"]),

    ("File system resize",

        ["FilesystemResizeUnmounted", "FilesystemResizeMounted"],

        ["linux", "windows"]),

    ("Swap partition configuration", ["AddSwap"], ["linux"]),

    ("SSH keys removal", ["DeleteSSHKeys"], ["linux"]),

    ("Temporal RDP disabling", ["DisableRemoteDesktopConnections"],

        ["windows"]),

    ("SELinux relabeling at next boot", ["SELinuxAutorelabel"], ["linux"]),

    ("Hostname/Computer Name assignment", ["AssignHostname"],

        ["windows", "linux"]),

    ("Password change", ["ChangePassword"], ["windows", "linux"]),

    ("File injection", ["EnforcePersonality"], ["windows", "linux"])

]

class Reset(Exception):

    pass

class metadata_monitor(object):

    def __init__(self, session, meta):

        self.session = session

        self.meta = meta

    def __enter__(self):

        self.old = {}

        for (k, v) in self.meta.items():

            self.old[k] = v

    def __exit__(self, type, value, traceback):

        d = self.session['dialog']

        altered = {}

        added = {}

        for (k, v) in self.meta.items():

            if k not in self.old:

                added[k] = v

            elif self.old[k] != v:

                altered[k] = v

        if not (len(added) or len(altered)):

            return

        msg = "The last action has changed some image properties:\n\n"

        if len(added):

            msg += "New image properties:\n"

            for (k, v) in added.items():

                msg += '    %s: "%s"\n' % (k, v)

            msg += "\n"

        if len(altered):

            msg += "Updated image properties:\n"

            for (k, v) in altered.items():

                msg += '    %s: "%s" -> "%s"\n' % (k, self.old[k], v)

            msg += "\n"

        self.session['metadata'].update(added)

        self.session['metadata'].update(altered)

        d.msgbox(msg, title="Image Property Changes", width=MSGBOX_WIDTH)

def extract_metadata_string(session):

    metadata = ['%s=%s' % (k, v) for (k, v) in session['metadata'].items()]

    if 'task_metadata' in session:

        metadata.extend("%s=yes" % m for m in session['task_metadata'])

    return '\n'.join(metadata) + '\n'

def confirm_exit(d, msg=''):

    return not d.yesno("%s Do you want to exit?" % msg, width=YESNO_WIDTH)

def confirm_reset(d):

    return not d.yesno("Are you sure you want to reset everything?",

                       width=YESNO_WIDTH, defaultno=1)

def update_background_title(session):

    d = session['dialog']

    dev = session['device']

    MB = 2 ** 20

    size = (dev.meta['SIZE'] + MB - 1) // MB

    shrinked = 'shrinked' in session and session['shrinked']

    postfix = " (shrinked)" if shrinked else ''

    title = "OS: %s, Distro: %s, Size: %dMB%s" % \

            (dev.ostype, dev.distro, size, postfix)

    d.setBackgroundTitle(title)

def extract_image(session):

    d = session['dialog']

    dir = os.getcwd()

    while 1:

        if dir and dir[-1] != os.sep:

            dir = dir + os.sep

        (code, path) = d.fselect(dir, 10, 50, title="Save image as...")

        if code in (d.DIALOG_CANCEL, d.DIALOG_ESC):

            return False

        if os.path.isdir(path):

            dir = path

            continue

        if os.path.isdir("%s.meta" % path):

            d.msgbox("Can't overwrite directory `%s.meta'" % path,

                     width=MSGBOX_WIDTH)

            continue

        if os.path.isdir("%s.md5sum" % path):

            d.msgbox("Can't overwrite directory `%s.md5sum'" % path,

                     width=MSGBOX_WIDTH)

            continue

        basedir = os.path.dirname(path)

        name = os.path.basename(path)

        if not os.path.exists(basedir):

            d.msgbox("Directory `%s' does not exist" % basedir,

                     width=MSGBOX_WIDTH)

            continue

        dir = basedir

        if len(name) == 0:

            continue

        files = ["%s%s" % (path, ext) for ext in ('', '.meta', '.md5sum')]

        overwrite = filter(os.path.exists, files)

        if len(overwrite) > 0:

            if d.yesno("The following file(s) exist:\n"

                       "%s\nDo you want to overwrite them?" %

                       "\n".join(overwrite), width=YESNO_WIDTH):

                continue

        out = GaugeOutput(d, "Image Extraction", "Extracting image...")

        try:

            dev = session['device']

            if "checksum" not in session:

                size = dev.meta['SIZE']

                md5 = MD5(out)

                session['checksum'] = md5.compute(session['snapshot'], size)

            # Extract image file

            dev.out = out

            dev.dump(path)

            # Extract metadata file

            out.output("Extracting metadata file...")

            with open('%s.meta' % path, 'w') as f:

                f.write(extract_metadata_string(session))

            out.success('done')

            # Extract md5sum file

            out.output("Extracting md5sum file...")

            md5str = "%s %s\n" % (session['checksum'], name)

            with open('%s.md5sum' % path, 'w') as f:

                f.write(md5str)

            out.success("done")

        finally:

            out.cleanup()

        d.msgbox("Image file `%s' was successfully extracted!" % path,

                 width=MSGBOX_WIDTH)

        break

    return True

def upload_image(session):

    d = session["dialog"]

    size = session['device'].meta['SIZE']

    if "account" not in session:

        d.msgbox("You need to provide your ~okeanos login username before you "

                 "can upload images to pithos+", width=MSGBOX_WIDTH)

        return False

    if "token" not in session:

        d.msgbox("You need to provide your ~okeanos account authentication "

                 "token before you can upload images to pithos+",

                 width=MSGBOX_WIDTH)

        return False

    while 1:

        init = session["upload"] if "upload" in session else ''

        (code, answer) = d.inputbox("Please provide a filename:", init=init,

                                    width=INPUTBOX_WIDTH)

        if code in (d.DIALOG_CANCEL, d.DIALOG_ESC):

            return False

        filename = answer.strip()

        if len(filename) == 0:

            d.msgbox("Filename cannot be empty", width=MSGBOX_WIDTH)

            continue

        break

    out = GaugeOutput(d, "Image Upload", "Uploading...")

    try:

        if 'checksum' not in session:

            md5 = MD5(out)

            session['checksum'] = md5.compute(session['snapshot'], size)

        kamaki = Kamaki(session['account'], session['token'], out)

        try:

            # Upload image file

            with open(session['snapshot'], 'rb') as f:

                session["upload"] = kamaki.upload(f, size, filename,

                                                  "Calculating block hashes",

                                                  "Uploading missing blocks")

            # Upload metadata file

            out.output("Uploading metadata file...")

            metastring = extract_metadata_string(session)

            kamaki.upload(StringIO.StringIO(metastring), size=len(metastring),

                          remote_path="%s.meta" % filename)

            out.success("done")

            # Upload md5sum file

            out.output("Uploading md5sum file...")

            md5str = "%s %s\n" % (session['checksum'], filename)

            kamaki.upload(StringIO.StringIO(md5str), size=len(md5str),

                          remote_path="%s.md5sum" % filename)

            out.success("done")

        except ClientError as e:

            d.msgbox("Error in pithos+ client: %s" % e.message,

                     title="Pithos+ Client Error", width=MSGBOX_WIDTH)

            if 'upload' in session:

                del session['upload']

            return False

    finally:

        out.cleanup()

    d.msgbox("Image file `%s' was successfully uploaded to pithos+" % filename,

             width=MSGBOX_WIDTH)

    return True

def register_image(session):

    d = session["dialog"]

    if "account" not in session:

        d.msgbox("You need to provide your ~okeanos login username before you "

                 "can register an images to cyclades",

                 width=MSGBOX_WIDTH)

        return False

    if "token" not in session:

        d.msgbox("You need to provide your ~okeanos account authentication "

                 "token before you can register an images to cyclades",

                 width=MSGBOX_WIDTH)

        return False

    if "upload" not in session:

        d.msgbox("You need to upload the image to pithos+ before you can "

                 "register it to cyclades", width=MSGBOX_WIDTH)

        return False

    while 1:

        (code, answer) = d.inputbox("Please provide a registration name:",

                                    width=INPUTBOX_WIDTH)

        if code in (d.DIALOG_CANCEL, d.DIALOG_ESC):

            return False

        name = answer.strip()

        if len(name) == 0:

            d.msgbox("Registration name cannot be empty", width=MSGBOX_WIDTH)

            continue

        break

    metadata = {}

    metadata.update(session['metadata'])

    if 'task_metadata' in session:

        for key in session['task_metadata']:

            metadata[key] = 'yes'

    out = GaugeOutput(d, "Image Registration", "Registrating image...")

    try:

        out.output("Registring image to cyclades...")

        try:

            kamaki = Kamaki(session['account'], session['token'], out)

            kamaki.register(name, session['upload'], metadata)

            out.success('done')

        except ClientError as e:

            d.msgbox("Error in pithos+ client: %s" % e.message)

            return False

    finally:

        out.cleanup()

    d.msgbox("Image `%s' was successfully registered to cyclades as `%s'" %

             (session['upload'], name), width=MSGBOX_WIDTH)

    return True

def kamaki_menu(session):

    d = session['dialog']

    default_item = "Account"

    account = Kamaki.get_account()

    if account:

        session['account'] = account

    token = Kamaki.get_token()

    if token:

        session['token'] = token

    while 1:

        account = session["account"] if "account" in session else "<none>"

        token = session["token"] if "token" in session else "<none>"

        upload = session["upload"] if "upload" in session else "<none>"

        choices = [("Account", "Change your ~okeanos username: %s" % account),

                   ("Token", "Change your ~okeanos token: %s" % token),

                   ("Upload", "Upload image to pithos+"),

                   ("Register", "Register the image to cyclades: %s" % upload)]

        (code, choice) = d.menu(

            text="Choose one of the following or press <Back> to go back.",

            width=MENU_WIDTH, choices=choices, cancel="Back", height=13,

            menu_height=5, default_item=default_item,

            title="Image Registration Menu")

        if code in (d.DIALOG_CANCEL, d.DIALOG_ESC):

            return False

        if choice == "Account":

            default_item = "Account"

            (code, answer) = d.inputbox(

                "Please provide your ~okeanos account e-mail address:",

                init=session["account"] if "account" in session else '',

                width=70)

            if code in (d.DIALOG_CANCEL, d.DIALOG_ESC):

                continue

            if len(answer) == 0 and "account" in session:

                    del session["account"]

            else:

                session["account"] = answer.strip()

                Kamaki.save_account(session['account'])

                default_item = "Token"

        elif choice == "Token":

            default_item = "Token"

            (code, answer) = d.inputbox(

                "Please provide your ~okeanos account authetication token:",

                init=session["token"] if "token" in session else '',

                width=70)

            if code in (d.DIALOG_CANCEL, d.DIALOG_ESC):

                continue

            if len(answer) == 0 and "token" in session:

                del session["token"]

            else:

                session["token"] = answer.strip()

                Kamaki.save_token(session['account'])

                default_item = "Upload"

        elif choice == "Upload":

            if upload_image(session):

                default_item = "Register"

            else:

                default_item = "Upload"

        elif choice == "Register":

            if register_image(session):

                return True

            else:

                default_item = "Register"

def add_property(session):

    d = session['dialog']

    while 1:

        (code, answer) = d.inputbox("Please provide a name for a new image"

                                    " property:", width=INPUTBOX_WIDTH)

        if code in (d.DIALOG_CANCEL, d.DIALOG_ESC):

            return False

        name = answer.strip()

        if len(name) == 0:

            d.msgbox("A property name cannot be empty", width=MSGBOX_WIDTH)

            continue

        break

    while 1:

        (code, answer) = d.inputbox("Please provide a value for image "

                                    "property %s" % name, width=INPUTBOX_WIDTH)

        if code in (d.DIALOG_CANCEL, d.DIALOG_ESC):

            return False

        value = answer.strip()

        if len(value) == 0:

            d.msgbox("Value cannot be empty", width=MSGBOX_WIDTH)

            continue

        break

    session['metadata'][name] = value

    return True

def modify_properties(session):

    d = session['dialog']

    while 1:

        choices = []

        for (key, val) in session['metadata'].items():

            choices.append((str(key), str(val)))

        (code, choice) = d.menu(

            "In this menu you can edit existing image properties or add new "

            "ones. Be careful! Most properties have special meaning and "

            "alter the image deployment behaviour. Press <HELP> to see more "

            "information about image properties. Press <BACK> when done.",

            height=18, width=MENU_WIDTH, choices=choices, menu_height=10,

            ok_label="Edit", extra_button=1, extra_label="Add", cancel="Back",

            help_button=1, title="Image Properties")

        if code in (d.DIALOG_CANCEL, d.DIALOG_ESC):

            return True

        # Edit button

        elif code == d.DIALOG_OK:

            (code, answer) = d.inputbox("Please provide a new value for the "

                                        "image property with name `%s':" %

                                        choice,

                                        init=session['metadata'][choice],

                                        width=INPUTBOX_WIDTH)

            if code not in (d.DIALOG_CANCEL, d.DIALOG_ESC):

                value = answer.strip()

                if len(value) == 0:

                    d.msgbox("Value cannot be empty!")

                    continue

                else:

                    session['metadata'][choice] = value

        # ADD button

        elif code == d.DIALOG_EXTRA:

            add_property(session)

        elif code == 'help':

            help_file = get_help_file("image_properties")

            assert os.path.exists(help_file)

            d.textbox(help_file, title="Image Properties", width=70, height=40)

def delete_properties(session):

    d = session['dialog']

    choices = []

    for (key, val) in session['metadata'].items():

        choices.append((key, "%s" % val, 0))

    (code, to_delete) = d.checklist("Choose which properties to delete:",

                                    choices=choices, width=CHECKBOX_WIDTH)

    # If the user exits with ESC or CANCEL, the returned tag list is empty.

    for i in to_delete:

        del session['metadata'][i]

    cnt = len(to_delete)

    if cnt > 0:

        d.msgbox("%d image properties were deleted." % cnt, width=MSGBOX_WIDTH)

        return True

    else:

        return False

def exclude_tasks(session):

    d = session['dialog']

    index = 0

    displayed_index = 1

    choices = []

    mapping = {}

    if 'excluded_tasks' not in session:

        session['excluded_tasks'] = []

    if -1 in session['excluded_tasks']:

        if not d.yesno("Image deployment configuration is disabled. "

                       "Do you wish to enable it?", width=YESNO_WIDTH):

            session['excluded_tasks'].remove(-1)

        else:

            return False

    for (msg, task, osfamily) in CONFIGURATION_TASKS:

        if session['metadata']['OSFAMILY'] in osfamily:

            checked = 1 if index in session['excluded_tasks'] else 0

            choices.append((str(displayed_index), msg, checked))

            mapping[displayed_index] = index

            displayed_index += 1

        index += 1

    while 1:

        (code, tags) = d.checklist(

            text="Please choose which configuration tasks you would like to "

                 "prevent from running during image deployment. "

                 "Press <No Config> to supress any configuration. "

                 "Press <Help> for more help on the image deployment "

                 "configuration tasks.",

            choices=choices, height=19, list_height=8, width=CHECKBOX_WIDTH,

            help_button=1, extra_button=1, extra_label="No Config",

            title="Exclude Configuration Tasks")

        if code in (d.DIALOG_CANCEL, d.DIALOG_ESC):

            return False

        elif code == d.DIALOG_HELP:

            help_file = get_help_file("configuration_tasks")

            assert os.path.exists(help_file)

            d.textbox(help_file, title="Configuration Tasks",

                      width=70, height=40)

        # No Config button

        elif code == d.DIALOG_EXTRA:

            session['excluded_tasks'] = [-1]

            session['task_metadata'] = ["EXCLUDE_ALL_TASKS"]

            break

        elif code == d.DIALOG_OK:

            session['excluded_tasks'] = []

            for tag in tags:

                session['excluded_tasks'].append(mapping[int(tag)])

            exclude_metadata = []

            for task in session['excluded_tasks']:

                exclude_metadata.extend(CONFIGURATION_TASKS[task][1])

            session['task_metadata'] = map(lambda x: "EXCLUDE_TASK_%s" % x,

                                           exclude_metadata)

            break

    return True

def sysprep(session):

    d = session['dialog']

    image_os = session['image_os']

    # Is the image already shrinked?

    if 'shrinked' in session and session['shrinked']:

        msg = "It seems you have shrinked the image. Running system " \

              "preparation tasks on a shrinked image is dangerous."

        if d.yesno("%s\n\nDo you really want to continue?" % msg,

                   width=YESNO_WIDTH, defaultno=1):

            return

    wrapper = textwrap.TextWrapper(width=65)

    help_title = "System Preperation Tasks"

    sysprep_help = "%s\n%s\n\n" % (help_title, '=' * len(help_title))

    if 'exec_syspreps' not in session:

        session['exec_syspreps'] = []

    all_syspreps = image_os.list_syspreps()

    # Only give the user the choice between syspreps that have not ran yet

    syspreps = [s for s in all_syspreps if s not in session['exec_syspreps']]

    if len(syspreps) == 0:

        d.msgbox("No system preparation task available to run!",

                 title="System Preperation", width=MSGBOX_WIDTH)

        return

    while 1:

        choices = []

        index = 0

        for sysprep in syspreps:

            name, descr = image_os.sysprep_info(sysprep)

            display_name = name.replace('-', ' ').capitalize()

            sysprep_help += "%s\n" % display_name

            sysprep_help += "%s\n" % ('-' * len(display_name))

            sysprep_help += "%s\n\n" % wrapper.fill(" ".join(descr.split()))

            enabled = 1 if sysprep.enabled else 0

            choices.append((str(index + 1), display_name, enabled))

            index += 1

        (code, tags) = d.checklist(

            "Please choose which system preperation tasks you would like to "

            "run on the image. Press <Help> to see details about the system "

            "preperation tasks.", title="Run system preperation tasks",

            choices=choices, width=70, ok_label="Run", help_button=1)

        if code in (d.DIALOG_CANCEL, d.DIALOG_ESC):

            return False

        elif code == d.DIALOG_HELP:

            d.scrollbox(sysprep_help, width=HELP_WIDTH)

        elif code == d.DIALOG_OK:

            # Enable selected syspreps and disable the rest

            for i in range(len(syspreps)):

                if str(i + 1) in tags:

                    image_os.enable_sysprep(syspreps[i])

                    session['exec_syspreps'].append(syspreps[i])

                else:

                    image_os.disable_sysprep(syspreps[i])

            out = InfoBoxOutput(d, "Image Configuration")

            try:

                dev = session['device']

                dev.out = out

                dev.mount(readonly=False)

                try:

                    # The checksum is invalid. We have mounted the image rw

                    if 'checksum' in session:

                        del session['checksum']

                    # Monitor the metadata changes during syspreps

                    with metadata_monitor(session, image_os.meta):

                        image_os.out = out

                        image_os.do_sysprep()

                        image_os.out.finalize()

                    # Disable syspreps that have ran

                    for sysprep in session['exec_syspreps']:

                        image_os.disable_sysprep(sysprep)

                finally:

                    dev.umount()

            finally:

                out.cleanup()

            break

    return True

def shrink(session):

    d = session['dialog']

    dev = session['device']

    shrinked = 'shrinked' in session and session['shrinked']

    if shrinked:

        d.msgbox("The image is already shrinked!", title="Image Shrinking",

                 width=MSGBOX_WIDTH)

        return True

    msg = "This operation will shrink the last partition of the image to " \

          "reduce the total image size. If the last partition is a swap " \

          "partition, then this partition is removed and the partition " \

          "before that is shrinked. The removed swap partition will be " \

          "recreated during image deployment."

    if not d.yesno("%s\n\nDo you want to continue?" % msg, width=70,

                   height=12, title="Image Shrinking"):

        with metadata_monitor(session, dev.meta):

            dev.out = InfoBoxOutput(d, "Image Shrinking", height=4)

            dev.shrink()

            dev.out.finalize()

        session['shrinked'] = True

        update_background_title(session)

    else:

        return False

    return True

def customization_menu(session):

    d = session['dialog']

    choices = [("Sysprep", "Run various image preperation tasks"),

               ("Shrink", "Shrink image"),

               ("View/Modify", "View/Modify image properties"),

               ("Delete", "Delete image properties"),

               ("Exclude", "Exclude various deployment tasks from running")]

    default_item = 0

    actions = {"Sysprep": sysprep,

               "Shrink": shrink,

               "View/Modify": modify_properties,

               "Delete": delete_properties,

               "Exclude": exclude_tasks}

    while 1:

        (code, choice) = d.menu(

            text="Choose one of the following or press <Back> to exit.",

            width=MENU_WIDTH, choices=choices, cancel="Back", height=13,

            menu_height=len(choices), default_item=choices[default_item][0],

            title="Image Customization Menu")

        if code in (d.DIALOG_CANCEL, d.DIALOG_ESC):

            break

        elif choice in actions:

            default_item = [entry[0] for entry in choices].index(choice)

            if actions[choice](session):

                default_item = (default_item + 1) % len(choices)

def main_menu(session):

    d = session['dialog']

    dev = session['device']

    update_background_title(session)

    choices = [("Customize", "Customize image & ~okeanos deployment options"),

               ("Register", "Register image to ~okeanos"),

               ("Extract", "Dump image to local file system"),

               ("Reset", "Reset everything and start over again"),

               ("Help", "Get help for using snf-image-creator")]

    default_item = "Customize"

    actions = {"Customize": customization_menu, "Register": kamaki_menu,

               "Extract": extract_image}

    while 1:

        (code, choice) = d.menu(

            text="Choose one of the following or press <Exit> to exit.",

            width=MENU_WIDTH, choices=choices, cancel="Exit", height=13,

            default_item=default_item, menu_height=len(choices),

            title="Image Creator for ~okeanos (snf-image-creator version %s)" %

                  version)

        if code in (d.DIALOG_CANCEL, d.DIALOG_ESC):

            if confirm_exit(d):

                break

        elif choice == "Reset":

            if confirm_reset(d):

                d.infobox("Resetting snf-image-creator. Please wait...",

                          width=INFOBOX_WIDTH)

                raise Reset

        elif choice in actions:

            actions[choice](session)

def select_file(d, media):

    root = os.sep

    while 1:

        if media is not None:

            if not os.path.exists(media):

                d.msgbox("The file `%s' you choose does not exist." % media,

                         width=MSGBOX_WIDTH)

            else:

                break

        (code, media) = d.fselect(root, 10, 50,

                                  title="Please select input media")

        if code in (d.DIALOG_CANCEL, d.DIALOG_ESC):

            if confirm_exit(d, "You canceled the media selection dialog box."):

                sys.exit(0)

            else:

                media = None

                continue

    return media

def image_creator(d):

    usage = "Usage: %prog [options] [<input_media>]"

    parser = optparse.OptionParser(version=version, usage=usage)

    options, args = parser.parse_args(sys.argv[1:])

    if len(args) > 1:

        parser.error("Wrong numver of arguments")

    d.setBackgroundTitle('snf-image-creator')

    if os.geteuid() != 0:

        raise FatalError("You must run %s as root" % parser.get_prog_name())

    media = select_file(d, args[0] if len(args) == 1 else None)

    out = GaugeOutput(d, "Initialization", "Initializing...")

    disk = Disk(media, out)

    def signal_handler(signum, frame):

        out.cleanup()

        disk.cleanup()

    signal.signal(signal.SIGINT, signal_handler)

    try:

        snapshot = disk.snapshot()

        dev = disk.get_device(snapshot)

        metadata = {}

        for (key, value) in dev.meta.items():

            metadata[str(key)] = str(value)

        dev.mount(readonly=True)

        out.output("Collecting image metadata...")

        cls = os_cls(dev.distro, dev.ostype)

        image_os = cls(dev.root, dev.g, out)

        dev.umount()

        for (key, value) in image_os.meta.items():

            metadata[str(key)] = str(value)

        out.success("done")

        out.cleanup()

        # Make sure the signal handler does not call out.cleanup again

        def dummy(self):

            pass

        out.cleanup = type(GaugeOutput.cleanup)(dummy, out, GaugeOutput)

        session = {"dialog": d,

                   "disk": disk,

                   "snapshot": snapshot,

                   "device": dev,

                   "image_os": image_os,

                   "metadata": metadata}

        msg = "snf-image-creator detected a %s system on the input media. " \

              "Would you like to run a wizards to assists you through the " \

              "image creation process?\n\nChoose <Yes> to run the wizard, " \

              "<No> to run the snf-image-creator in expert mode or press " \

              "ESC to quit the program." \

              % (dev.ostype if dev.ostype == dev.distro else "%s (%s)" %

                 (dev.ostype, dev.distro))

        update_background_title(session)

        while True:

            code = d.yesno(msg, width=YESNO_WIDTH, height=12)

            if code == d.DIALOG_OK:

                if wizard(session):

                    break

            elif code == d.DIALOG_CANCEL:

                main_menu(session)

                break

            if confirm_exit(d):

                break

        d.infobox("Thank you for using snf-image-creator. Bye", width=53)

    finally:

        disk.cleanup()

    return 0

def main():

    d = dialog.Dialog(dialog="dialog")

    # Add extra button in dialog library

    dialog._common_args_syntax["extra_button"] = \

        lambda enable: dialog._simple_option("--extra-button", enable)

    dialog._common_args_syntax["extra_label"] = \

        lambda string: ("--extra-label", string)

    while 1:

        try:

            try:

                ret = image_creator(d)

                sys.exit(ret)

            except FatalError as e:

                msg = textwrap.fill(str(e), width=70)

                d.infobox(msg, width=INFOBOX_WIDTH, title="Fatal Error")

                sys.exit(1)

        except Reset:

            continue

# vim: set sta sts=4 shiftwidth=4 sw=4 et ai :