[SoaS] [PATCH 1b] substitute was: [PATCH 1/5] Support Live image mounting in fs.py
Frederick Grose
fgrose at gmail.com
Sat Sep 17 17:54:12 EDT 2011
Patch 1b of 2 substitute patches to replace an earlier patch with new
features:
commit 3501e953449d17a53b669bb80bf4e96d8a8e4b25
Author: Frederick Grose <fgrose at sugarlabs.org>
Date: Sat Sep 17 17:29:03 2011 -0400
Provide a new LiveImageMount class for mounting a LiveOS filesystem.
Mount the LiveOS filesystem with its own or a substitute overlay.
Provide mounting options for read-write or read-only overlays.
This supports image customization.
diff --git a/imgcreate/fs.py b/imgcreate/fs.py
index e71032e..6d04c4a 100644
--- a/imgcreate/fs.py
+++ b/imgcreate/fs.py
@@ -684,6 +684,103 @@ class DeviceMapperSnapshot(object):
except ValueError:
raise SnapshotError("Failed to parse dmsetup status: " + out)
+
+class LiveImageMount(object):
+ """A class for mounting a LiveOS image installed with an active
overlay."""
+
+ def __init__(self, disk, mountdir, overlay=None, tmpdir='/tmp',
ops=None):
+ self.disk = disk
+ self.mountdir = mountdir
+ self.overlay = overlay
+ self.tmpdir = tmpdir
+ self.ops = ops
+ self.__created = False
+ self.squashmnt = None
+ self.homemnt = None
+ self.mntlive = None
+
+ def __create(self, ops=None):
+ if self.__created:
+ return
+ self.liveosdevmnt = DiskMount(self.disk,
+ os.path.join(self.tmpdir, 'device'),
ops=ops)
+ self.liveosdevmnt.mount(ops)
+ liveosdir = os.path.join(self.liveosdevmnt.mountdir, 'LiveOS')
+ sqfs_img = os.path.join(liveosdir, 'squashfs.img')
+ if os.path.exists(sqfs_img):
+ self.squashloop = LoopbackDisk(sqfs_img, None, ['-r'])
+ self.squashmnt = DiskMount(self.squashloop,
+ os.path.join(self.tmpdir, 'squash'),
ops='ro')
+ self.squashmnt.mount('ro')
+ rootfs_img = os.path.join(self.squashmnt.mountdir,
+ 'LiveOS', 'ext3fs.img')
+ else:
+ rootfs_img = os.path.join(liveosdir, 'ext3fs.img')
+ if not os.path.exists(rootfs_img):
+ raise SnapshotError("Failed to find a LiveOS root image.")
+ self.imgloop = LoopbackDisk(rootfs_img, None, ['-r'])
+ if not self.overlay:
+ for f in os.listdir(liveosdir):
+ if f.find('overlay-') == 0:
+ self.overlay = os.path.join(liveosdir, f)
+ break
+ self.cowloop = LoopbackDisk(self.overlay, None, ops)
+ self.dm_liveimage = DeviceMapperSnapshot(self.imgloop,
self.cowloop,
+ ops)
+ self.dm_livemount = DiskMount(self.dm_liveimage, self.mountdir,
+ ops=ops)
+ home_img = os.path.join(liveosdir, 'home.img')
+ if os.path.exists(home_img):
+ homedir = os.path.join(self.mountdir, 'home')
+ self.homemnt = LoopbackMount(home_img, homedir, ops=ops)
+ self.__created = True
+
+ def mount(self, ops=None):
+ if ops is None:
+ ops = self.ops
+ try:
+ self.__create(ops)
+ if not self.liveosdevmnt.mounted:
+ self.liveosdevmnt.mount(ops)
+ if self.squashmnt and not self.squashmnt.mounted:
+ self.squashmnt.mount('ro')
+ self.dm_livemount.mount(ops)
+ if self.homemnt:
+ self.homemnt.mount(ops)
+ mntlivedir = os.path.join(self.mountdir, 'mnt', 'live')
+ if not os.path.exists(mntlivedir):
+ os.makedirs(mntlivedir)
+ self.mntlive = BindChrootMount(self.liveosdevmnt.mountdir,
+ '', mntlivedir, ops)
+ self.mntlive.mount(ops)
+ except MountError, e:
+ self.cleanup()
+ raise SnapshotError("Failed to mount %s : %s" % (self.disk, e))
+
+ def remount(self, ops):
+ try:
+ self.liveosdevmnt.remount(ops)
+ if self.homemnt:
+ self.homemnt.remount(ops)
+ self.mntlive.reremount(ops)
+ except MountError, e:
+ self.cleanup()
+ raise SnapshotError("Failed to remount %s as %s : %s" %
+ (self.disk, ops, e))
+
+ def cleanup(self):
+ if self.mntlive:
+ self.mntlive.unmount()
+ if self.homemnt:
+ self.homemnt.cleanup()
+ self.dm_livemount.unmount()
+ self.dm_liveimage.remove()
+ if self.squashmnt:
+ self.squashmnt.cleanup()
+ self.liveosdevmnt.cleanup()
+ self.__created = False
+
+
def create_image_minimizer(path, image, compress_type, target_size = None,
tmpdir = "/tmp"):
"""
On Thu, Apr 14, 2011 at 12:02 PM, Frederick Grose <fgrose at gmail.com> wrote:
> [Patch 1/5]
> Author: Frederick Grose <fgrose at sugarlabs.org>
> Date: Thu Apr 14 09:29:14 2011 -0400
>
> Support Live image mounting.
>
> Provide DiskMount with mount options, DeviceMapperSnapshot with a
> device attribute, and a new LiveImageMount class.
>
> diff --git a/imgcreate/fs.py b/imgcreate/fs.py
> index d5307a2..0871182 100644
> --- a/imgcreate/fs.py
> +++ b/imgcreate/fs.py
> @@ -324,7 +324,6 @@ class LoopbackDisk(Disk):
> self.device = None
>
>
> -
> class SparseLoopbackDisk(LoopbackDisk):
> """A Disk backed by a sparse file via the loop module."""
> def __init__(self, lofile, size):
> @@ -377,11 +376,12 @@ class Mount:
>
> class DiskMount(Mount):
> """A Mount object that handles mounting of a Disk."""
> - def __init__(self, disk, mountdir, fstype = None, rmmountdir = True):
> + def __init__(self, disk, mountdir, fstype=None, rmmountdir=True,
> ops=None):
> Mount.__init__(self, mountdir)
>
> self.disk = disk
> self.fstype = fstype
> + self.ops = ops
> self.rmmountdir = rmmountdir
>
> self.mounted = False
> @@ -435,6 +435,8 @@ class DiskMount(Mount):
> args = [ "/bin/mount", self.disk.device, self.mountdir ]
> if self.fstype:
> args.extend(["-t", self.fstype])
> + if self.ops:
> + args.extend(['-o', self.ops])
>
> rc = call(args)
> if rc != 0:
> @@ -530,6 +532,7 @@ class ExtDiskMount(DiskMount):
> self.__resize_filesystem(size)
> return minsize
>
> +
> class DeviceMapperSnapshot(object):
> def __init__(self, imgloop, cowloop):
> self.imgloop = imgloop
> @@ -541,6 +544,7 @@ class DeviceMapperSnapshot(object):
> def get_path(self):
> if self.__name is None:
> return None
> + return self.device
> return os.path.join("/dev/mapper", self.__name)
> path = property(get_path)
>
> @@ -569,6 +573,7 @@ class DeviceMapperSnapshot(object):
> string.join(args, " "))
>
> self.__created = True
> + self.device = os.path.join('/dev/mapper', self.__name)
>
> def remove(self, ignore_errors = False):
> if not self.__created:
> @@ -610,6 +615,89 @@ class DeviceMapperSnapshot(object):
> except ValueError:
> raise SnapshotError("Failed to parse dmsetup status: " + out)
>
> +
> +class LiveImageMount(object):
> + """A class for mounting a LiveOS image installed with an active
> overlay."""
> +
> + def __init__(self, disk, mountdir, overlay, tmpdir='/tmp'):
> + self.disk = disk
> + self.mountdir = mountdir
> + self.overlay = overlay
> + self.tmpdir = tmpdir
> + self.__created = False
> + self.squashmnt = None
> + self.homemnt = None
> + self.mntlive = None
> +
> + def __create(self):
> + if self.__created:
> + return
> + self.liveosdevmnt = DiskMount(self.disk,
> + os.path.join(self.tmpdir, 'device'))
> + self.liveosdevmnt.mount()
> + liveosdir = os.path.join(self.liveosdevmnt.mountdir, 'LiveOS')
> + sqfs_img = os.path.join(liveosdir, 'squashfs.img')
> + if os.path.exists(sqfs_img):
> + self.squashloop = LoopbackDisk(sqfs_img, None)
> + self.squashmnt = DiskMount(self.squashloop,
> + os.path.join(self.tmpdir,
> 'squash'))
> + self.squashmnt.mount()
> + rootfs_img = os.path.join(self.squashmnt.mountdir,
> + 'LiveOS', 'ext3fs.img')
> + else:
> + rootfs_img = os.path.join(liveosdir, 'ext3fs.img')
> + if not os.path.exists(rootfs_img):
> + raise SnapshotError("Failed to find a LiveOS root image.")
> + self.imgloop = LoopbackDisk(rootfs_img, None)
> + self.overlay = os.path.join(liveosdir, self.overlay)
> + self.cowloop = LoopbackDisk(self.overlay, None)
> + home_img = os.path.join(liveosdir, 'home.img')
> + self.dm_liveimage = DeviceMapperSnapshot(self.imgloop,
> self.cowloop)
> + self.dm_livemount = DiskMount(self.dm_liveimage, self.mountdir)
> + if os.path.exists(home_img):
> + homedir = os.path.join(self.mountdir, 'home')
> + self.homemnt = LoopbackMount(home_img, homedir)
> + self.__created = True
> +
> + def mount(self):
> + try:
> + self.__create()
> + if not self.liveosdevmnt.mounted:
> + self.liveosdevmnt.mount()
> + if not self.squashmnt.mounted:
> + self.squashmnt.mount()
> + self.dm_livemount.mount()
> + if self.homemnt:
> + self.homemnt.mount()
> + mntlivedir = os.path.join(self.mountdir, 'mnt', 'live')
> + if not os.path.exists(mntlivedir):
> + os.makedirs(mntlivedir)
> + self.mntlive = BindChrootMount(self.liveosdevmnt.mountdir,
> + '', mntlivedir)
> + self.mntlive.mount()
> + except MountError, e:
> + raise SnapshotError("Failed to mount %s : %s" % (self.disk,
> e))
> + self.cleanup()
> +
> + def unmount(self):
> + if self.mntlive:
> + self.mntlive.unmount()
> + if self.homemnt:
> + self.homemnt.unmount()
> + self.dm_livemount.unmount()
> + self.liveosdevmnt.unmount()
> +
> + def cleanup(self):
> + self.unmount()
> + if self.homemnt:
> + self.homemnt.cleanup()
> + self.dm_liveimage.remove()
> + if self.squashmnt:
> + self.squashmnt.cleanup()
> + self.liveosdevmnt.cleanup()
> + self.__created = False
> +
> +
> def create_image_minimizer(path, image, compress_type, target_size = None,
> tmpdir = "/tmp"):
> """
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