Synnefo » snf-image-creator

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from image_creator.os_type.unix import Unix, sysprep

from image_creator.util import warn, output

import re

import time

class Linux(Unix):

    def __init__(self, rootdev, ghandler):

        super(Linux, self).__init__(rootdev, ghandler)

        self._uuid = dict()

        self._persistent = re.compile('/dev/[hsv]d[a-z][1-9]*')

    def is_persistent(self, dev):

        return not self._persistent.match(dev)

    def get_uuid(self, dev):

        if dev in self._uuid:

            return self._uuid[dev]

        for attr in self.g.blkid(dev):

            if attr[0] == 'UUID':

                self._uuid[dev] = attr[1]

                return attr[1]

    @sysprep()

    def fix_acpid(self, print_header=True):

        """Replace acpid powerdown action scripts to immediately shutdown the

        system without checking if a GUI is running.

        """

        if print_header:

            output('Fixing acpid powerdown action')

        powerbtn_action = '#!/bin/sh\n\nPATH=/sbin:/bin:/usr/bin\n' \

                                'shutdown -h now \"Power button pressed\"\n'

        events_dir = '/etc/acpi/events'

        if not self.g.is_dir(events_dir):

            warn("No acpid event directory found")

            return

        event_exp = re.compile('event=(.+)', re.I)

        action_exp = re.compile('action=(.+)', re.I)

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

            if f['ftyp'] != 'r':

                continue

            fullpath = "%s/%s" % (events_dir, f['name'])

            event = ""

            action = ""

            for line in self.g.cat(fullpath).splitlines():

                m = event_exp.match(line)

                if m:

                    event = m.group(1)

                    continue

                m = action_exp.match(line)

                if m:

                    action = m.group(1)

                    continue

            if event.strip() == "button[ /]power":

                if action:

                    if not self.g.is_file(action):

                        warn("Acpid action file: %s does not exist" % action)

                        return

                    self.g.copy_file_to_file(action, \

                      "%s.orig.snf-image-creator-%d" % (action, time.time()))

                    self.g.write(action, powerbtn_action)

                    return

                else:

                    warn("Acpid event file %s does not contain and action")

                    return

            elif event.strip() == ".*":

                warn("Found action `.*'. Don't know how to handle this." \

                    " Please edit \%s' image file manually to make the " \

                    "system immediatelly shutdown when an power button acpi " \

                    "event occures" % action)

                return

    @sysprep()

    def persistent_net_rules(self, print_header=True):

        """Remove udev rules that will keep network interface names persistent

        after hardware changes and reboots. Those rules will be created again

        the next time the image runs.

        """

        if print_header:

            output('Removing persistent network interface names')

        rule_file = '/etc/udev/rules.d/70-persistent-net.rules'

        if self.g.is_file(rule_file):

            self.g.rm(rule_file)

    @sysprep()

    def remove_swap_entry(self, print_header=True):

        """Remove swap entry from /etc/fstab. If swap is the last partition

        then the partition will be removed when shrinking is performed. If the

        swap partition is not the last partition in the disk or if you are not

        going to shrink the image you should probably disable this.

        """

        if print_header:

            output('Removing swap entry from fstab')

        new_fstab = ""

        fstab = self.g.cat('/etc/fstab')

        for line in fstab.splitlines():

            entry = line.split('#')[0].strip().split()

            if len(entry) == 6 and entry[2] == 'swap':

                continue

            new_fstab += "%s\n" % line

        self.g.write('/etc/fstab', new_fstab)

    @sysprep()

    def persistent_devs(self, print_header=True):

        """Scan fstab & grub configuration files and replace all non-persistent

        device appearences with UUIDs.

        """

        if print_header:

            output('Replacing fstab & grub non-persistent device appearences')

        # convert all devices in fstab to persistent

        persistent_root = self._persistent_fstab()

        # convert all devices in grub1 to persistent

        self._persistent_grub1(persistent_root)

    def _persistent_grub1(self, new_root):

        if self.g.is_file('/boot/grub/menu.lst'):

            grub1 = '/boot/grub/menu.lst'

        elif self.g.is_file('/etc/grub.conf'):

            grub1 = '/etc/grub.conf'

        else:

            return

        self.g.aug_init('/', 0)

        try:

            roots = self.g.aug_match('/files%s/title[*]/kernel/root' % grub1)

            for root in roots:

                dev = self.g.aug_get(root)

                if not self.is_persistent(dev):

                    # This is not always correct. Grub may contain root entries

                    # for other systems, but we only support 1 OS per hard

                    # disk, so this shouldn't harm.

                    self.g.aug_set(root, new_root)

        finally:

            self.g.aug_save()

            self.g.aug_close()

    def _persistent_fstab(self):

        mpoints = self.g.mountpoints()

        if len(mpoints) == 0:

            pass  # TODO: error handling

        device_dict = dict([[mpoint, dev] for dev, mpoint in mpoints])

        root_dev = None

        new_fstab = ""

        fstab = self.g.cat('/etc/fstab')

        for line in fstab.splitlines():

            line, dev, mpoint = self._convert_fstab_line(line, device_dict)

            new_fstab += "%s\n" % line

            if mpoint == '/':

                root_dev = dev

        self.g.write('/etc/fstab', new_fstab)

        if root_dev is None:

            pass  # TODO: error handling

        return root_dev

    def _convert_fstab_line(self, line, devices):

        orig = line

        line = line.split('#')[0].strip()

        if len(line) == 0:

            return orig, "", ""

        entry = line.split()

        if len(entry) != 6:

            warn("Detected abnormal entry in fstab")

            return orig, "", ""

        dev = entry[0]

        mpoint = entry[1]

        if not self.is_persistent(dev):

            if mpoint in devices:

                dev = "UUID=%s" % self.get_uuid(devices[mpoint])

                entry[0] = dev

            else:

                # comment out the entry

                entry[0] = "#%s" % dev

            return " ".join(entry), dev, mpoint

        return orig, dev, mpoint

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