Synnefo » snf-image-creator

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

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from image_creator.util import FatalError

import textwrap

import re

def os_cls(distro, osfamily):

    """Given the distro name and the osfamily, return the appropriate class"""

    module = None

    classname = None

    try:

        module = __import__("image_creator.os_type.%s" % distro,

                            fromlist=['image_creator.os_type'])

        classname = distro.capitalize()

    except ImportError:

        module = __import__("image_creator.os_type.%s" % osfamily,

                            fromlist=['image_creator.os_type'])

        classname = osfamily.capitalize()

    return getattr(module, classname)

def add_prefix(target):

    def wrapper(self, *args):

        prefix = args[0]

        return map(lambda x: prefix + x, target(self, *args))

    return wrapper

def sysprep(enabled=True):

    """Decorator for system preparation tasks"""

    def wrapper(func):

        func.sysprep = True

        func.enabled = enabled

        func.executed = False

        return func

    return wrapper

class OSBase(object):

    """Basic operating system class"""

    def __init__(self, rootdev, ghandler, output):

        self.root = rootdev

        self.g = ghandler

        self.out = output

        # Collect metadata about the OS

        self.meta = {}

        self.meta['ROOT_PARTITION'] = "%d" % self.g.part_to_partnum(self.root)

        self.meta['OSFAMILY'] = self.g.inspect_get_type(self.root)

        self.meta['OS'] = self.g.inspect_get_distro(self.root)

        if self.meta['OS'] == "unknown":

            self.meta['OS'] = self.meta['OSFAMILY']

        self.meta['DESCRIPTION'] = self.g.inspect_get_product_name(self.root)

    def _is_sysprep(self, obj):

        return getattr(obj, 'sysprep', False) and callable(obj)

    def list_syspreps(self):

        objs = [getattr(self, name) for name in dir(self)

                if not name.startswith('_')]

        return [x for x in objs if self._is_sysprep(x) and x.executed is False]

    def sysprep_info(self, obj):

        assert self._is_sysprep(obj), "Object is not a sysprep"

        return (obj.__name__.replace('_', '-'), textwrap.dedent(obj.__doc__))

    def get_sysprep_by_name(self, name):

        """Returns the sysprep object with the given name"""

        error_msg = "Syprep operation %s does not exist for %s" % \

                    (name, self.__class__.__name__)

        method_name = name.replace('-', '_')

        method = None

        try:

            method = getattr(self, method_name)

        except AttributeError:

            raise FatalError(error_msg)

        if not self._is_sysprep(method):

            raise FatalError(error_msg)

        return method

    def enable_sysprep(self, obj):

        """Enable a system preparation operation"""

        setattr(obj.im_func, 'enabled', True)

    def disable_sysprep(self, obj):

        """Disable a system preparation operation"""

        setattr(obj.im_func, 'enabled', False)

    def print_syspreps(self):

        """Print enabled and disabled system preparation operations."""

        syspreps = self.list_syspreps()

        enabled = filter(lambda x: x.enabled, syspreps)

        disabled = filter(lambda x: not x.enabled, syspreps)

        wrapper = textwrap.TextWrapper()

        wrapper.subsequent_indent = '\t'

        wrapper.initial_indent = '\t'

        wrapper.width = 72

        self.out.output("Enabled system preparation operations:")

        if len(enabled) == 0:

            self.out.output("(none)")

        else:

            for sysprep in enabled:

                name = sysprep.__name__.replace('_', '-')

                descr = wrapper.fill(textwrap.dedent(sysprep.__doc__))

                self.out.output('    %s:\n%s\n' % (name, descr))

        self.out.output("Disabled system preparation operations:")

        if len(disabled) == 0:

            self.out.output("(none)")

        else:

            for sysprep in disabled:

                name = sysprep.__name__.replace('_', '-')

                descr = wrapper.fill(textwrap.dedent(sysprep.__doc__))

                self.out.output('    %s:\n%s\n' % (name, descr))

    @add_prefix

    def ls(self, directory):

        """List the name of all files under a directory"""

        return self.g.ls(directory)

    @add_prefix

    def find(self, directory):

        """List the name of all files recursively under a directory"""

        return self.g.find(directory)

    def foreach_file(self, directory, action, **kargs):

        """Perform an action recursively on all files under a directory.

        The following options are allowed:

        * maxdepth: If defined the action will not be performed on

          files that are below this level of directories under the

          directory parameter.

        * ftype: The action will only be performed on files of this

          type. For a list of all allowed filetypes, see here:

          http://libguestfs.org/guestfs.3.html#guestfs_readdir

        * exclude: Exclude all files that follow this pattern.

        """

        maxdepth = None if 'maxdepth' not in kargs else kargs['maxdepth']

        if maxdepth == 0:

            return

        # maxdepth -= 1

        maxdepth = None if maxdepth is None else maxdepth - 1

        kargs['maxdepth'] = maxdepth

        exclude = None if 'exclude' not in kargs else kargs['exclude']

        ftype = None if 'ftype' not in kargs else kargs['ftype']

        has_ftype = lambda x, y: y is None and True or x['ftyp'] == y

        for f in self.g.readdir(directory):

            if f['name'] in ('.', '..'):

                continue

            full_path = "%s/%s" % (directory, f['name'])

            if exclude and re.match(exclude, full_path):

                continue

            if has_ftype(f, 'd'):

                self.foreach_file(full_path, action, **kargs)

            if has_ftype(f, ftype):

                action(full_path)

    def do_sysprep(self):

        """Prepere system for image creation."""

        self.out.output('Preparing system for image creation:')

        tasks = self.list_syspreps()

        enabled = filter(lambda x: x.enabled, tasks)

        size = len(enabled)

        cnt = 0

        for task in enabled:

            cnt += 1

            self.out.output(('(%d/%d)' % (cnt, size)).ljust(7), False)

            task()

            setattr(task.im_func, 'executed', True)

        self.out.output()

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