pylorax.mount — Lorax 28.14.33 documentation

# Source code for pylorax.mount

    # mount.py
    #
    # Copyright (C) 2011-2015  Red Hat, Inc.
    #
    # 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, see <http://www.gnu.org/licenses/>.
    #
    # Author(s): Brian C. Lane <bcl@redhat.com>
    #
    import logging
    log = logging.getLogger("livemedia-creator")

    import os

    from pylorax.imgutils import mount, umount
    from pylorax.executils import execWithCapture

    class IsoMountpoint(object):
        """
        Mount the iso and check to make sure the vmlinuz and initrd.img files exist

        Also check the iso for a a stage2 image and set a flag and extract the
        iso's label.

        stage2 can be either LiveOS/squashfs.img or images/install.img
        """
        def __init__(self, iso_path, initrd_path=None):
            """
            Mount the iso

            :param str iso_path: Path to the iso to mount
            :param str initrd_path: Optional path to initrd

            initrd_path can be used to point to a tree with a newer
            initrd.img than the iso has. The iso is still used for stage2.

            self.kernel and self.initrd point to the kernel and initrd.
            self.stage2 is set to True if there is a stage2 image.
            self.repo is the path to the mounted iso if there is a /repodata dir.
            """
            self.label = None
            self.iso_path = iso_path
            self.initrd_path = initrd_path

            if not self.initrd_path:
                self.mount_dir = mount(self.iso_path, opts="loop")
            else:
                self.mount_dir = self.initrd_path

            kernel_list = [("/isolinux/vmlinuz", "/isolinux/initrd.img"),
                           ("/ppc/ppc64/vmlinuz", "/ppc/ppc64/initrd.img")]

            if os.path.isdir(self.mount_dir+"/repodata"):
                self.repo = self.mount_dir
            else:
                self.repo = None
            self.stage2 = os.path.exists(self.mount_dir+"/LiveOS/squashfs.img") or \
                          os.path.exists(self.mount_dir+"/images/install.img")

            try:
                for kernel, initrd in kernel_list:
                    if (os.path.isfile(self.mount_dir+kernel) and
                        os.path.isfile(self.mount_dir+initrd)):
                        self.kernel = self.mount_dir+kernel
                        self.initrd = self.mount_dir+initrd
                        break
                else:
                    raise Exception("Missing kernel and initrd file in iso, failed"
                                    " to search under: {0}".format(kernel_list))
            except:
                self.umount()
                raise

            self.get_iso_label()

        def umount( self ):
            """Unmount the iso"""
            if not self.initrd_path:
                umount(self.mount_dir)

        def get_iso_label(self):
            """
            Get the iso's label using isoinfo

            Sets self.label if one is found
            """
            isoinfo_output = execWithCapture("isoinfo", ["-d", "-i", self.iso_path])
            log.debug(isoinfo_output)
            for line in isoinfo_output.splitlines():
                if line.startswith("Volume id: "):
                    self.label = line[11:]
                    return