Further development in bundle_volume
[snf-image-creator] / image_creator / bundle_volume.py
index ee079a2..6e8ac47 100644 (file)
 
 import os
 import re
-import parted
 import uuid
+import tempfile
 from collections import namedtuple
 
+import parted
+
 from image_creator.util import get_command
 from image_creator.util import FatalError
 
 findfs = get_command('findfs')
 truncate = get_command('truncate')
 dd = get_command('dd')
-
-MB = 2 ** 20
-
-def fstable(f):
-    if not os.path.isfile(f):
-        raise FatalError("Unable to open: `%s'. File is missing." % f)
-
-    Entry = namedtuple('Entry', 'dev mpoint fs opts freq passno')
-
-    with open(f) as table:
-        for line in iter(table):
-            entry = line.split('#')[0].strip().split()
-            if len(entry) != 6:
-                continue
-            yield Entry(*entry)
-
-
-def get_root_partition():
-    for entry in fstable('/etc/fstab'):
-        if entry.mpoint == '/':
-            return entry.dev
-
-    raise FatalError("Unable to find root device in /etc/fstab")
-
-
-def is_mpoint(path):
-    for entry in fstable('/proc/mounts'):
-        if entry.mpoint == path:
-            return True
-    return False
-
-
-def mpoint(device):
-    for entry in fstable('/proc/mounts'):
-        if not entry.dev.startswith('/'):
-            continue
-
-        if os.path.realpath(entry.dev) == os.path.realpath(device):
-            return entry.mpoint
-
-    return ""
-
-
-def create_EBRs(src, dest):
-
-    # The Extended boot records precede the logical partitions they describe
-    extended = src.getExtendedPartition()
-    if not extended:
-        return
-
-    logical = src.getLogicalPartitions()
-    start = extended.geometry.start
-    for i in range(len(logical)):
-        end = logical[i].geometry.start - 1
-        dd('if=%s' % src.device.path, 'of=%s' % dest,
-            'count=%d' % (end - start + 1), 'conv=notrunc', 'seek=%d' % start,
-            'skip=%d' % start)
-        start = logical[i].geometry.end + 1
+dmsetup = get_command('dmsetup')
 
 
-def bundle_volume(out, meta):
+class BundleVolume():
+    _FileSystemEntry = namedtuple('FileSystemEntry',
+                                  'dev mpoint fs opts freq passno')
 
-    if is_mpoint('/mnt'):
-        raise FatalError('The directory /mnt where the image will be hosted'
-            'is mounted. Please unmount it and start over again.')
+    _Partition = namedtuple('Partition', 'num start end type fs mopts')
 
-    out.output('Searching for root device...', False)
-    root_part = get_root_partition()
+    def __init__(self, out, meta):
+        self.out = out
+        self.meta = meta
 
-    if root_part.startswith("UUID=") or root_part.startswith("LABEL="):
-        root_part = findfs(root_part).stdout.strip()
-    elif not root_part.startswith("/"):
-        raise FatalError("Unable to find a block device for: %s" % root_dev)
+        self.out.output('Searching for root device...', False)
+        root = self._get_root_partition()
 
-    if not re.match('/dev/[hsv]d[a-z][1-9]*$', root_part):
-        raise FatalError("Don't know how to handle root device: %s" % root_dev)
+        if root.startswith("UUID=") or root.startswith("LABEL="):
+            self.root = findfs(root).stdout.strip()
+        else:
+            self.root = root
 
-    part_to_dev = lambda p: re.split('[0-9]', p)[0]
+        if not re.match('/dev/[hsv]d[a-z][1-9]*$', self.root):
+            raise FatalError("Don't know how to handle root device: %s" % \
+                             self.root)
 
-    root_dev = part_to_dev(root_part)
+        self.disk = re.split('[0-9]', self.root)[0]
 
-    out.success('%s' % root_dev)
+        out.success('%s' % root_dev)
 
-    src_dev = parted.Device(root_dev)
+    def _read_fstable(f):
+        if not os.path.isfile(f):
+            raise FatalError("Unable to open: `%s'. File is missing." % f)
 
-    img = '/mnt/%s.diskdump' % uuid.uuid4().hex
-    disk_size = src_dev.getLength() * src_dev.sectorSize
+        with open(f) as table:
+            for line in iter(table):
+                entry = line.split('#')[0].strip().split()
+                if len(entry) != 6:
+                    continue
+                yield FileSystemEntry(*entry)
 
-    # Create sparse file to host the image
-    truncate("-s", "%d" % disk_size, img)
+    def _get_root_partition():
+        for entry in self._read_fstable('/etc/fstab'):
+            if entry.mpoint == '/':
+                return entry.dev
 
-    src_disk = parted.Disk(src_dev)
-    if src_disk.type != 'msdos':
-        raise FatalError('For now we can only handle msdos partition tables')
+        raise FatalError("Unable to find root device in /etc/fstab")
 
-    # Copy the MBR and the space between the MBR and the first partition.
-    # In Grub version 1 Stage 1.5 is located there.
-    first_sector = src_disk.getPrimaryPartitions()[0].geometry.start
+    def _is_mpoint(path):
+        for entry in fstable('/proc/mounts'):
+            if entry.mpoint == path:
+                return True
+        return False
 
-    dd('if=%s' % src_dev.path, 'of=%s' % img, 'bs=%d' % src_dev.sectorSize,
-        'count=%d' % first_sector, 'conv=notrunc')
-
-    # Create the Extended boot records (EBRs) in the image
-    create_EBRs(src_disk, img)
-
-    img_dev = parted.Device(img)
-    img_disk = parted.Disk(img_dev)
-
-    is_extended = lambda p: p.type == parted.PARTITION_EXTENDED
-    is_logical = lambda p: p.type == parted.PARTITION_LOGICAL
-
-    Partition = namedtuple('Partition', 'num start end type fs mpoint')
-
-    partitions = []
-    for p in src_disk.partitions:
-        g = p.geometry
-        f = p.fileSystem
-        partitions.append(Partition(p.number, g.start, g.end, p.type,
-            f.type if f is not None else '', mpoint(p.path)))
-
-    last = partitions[-1]
-    new_end = src_dev.getLength()
-    if last.fs == 'linux-swap(v1)':
-        size = (last.end - last.start + 1) * src_dev.sectorSize
-        meta['SWAP'] = "%d:%s" % (last.num, ((size + MB - 1) // MB))
-        
-        img_disk.deletePartition(img_disk.getPartitionBySector(last.start))
-        img_disk.commit()
-
-        if is_logical(last) and last.num == 5:
-            img_disk.deletePartition(img_disk.getExtendedPartition())
-            img_disk.commit()
-            partitions.remove(filter(is_extended, partitions)[0])
-
-        partitions.remove(last)
-        last = partitions[-1]
-
-        # Leave 2048 blocks at the end
-        new_end = last.end + 2048
-
-    if last.mpoint:
-        stat = os.statvfs(last.mpoint)
-        occupied_blocks = stat.f_blocks - stat.f_bavail
-        new_size = (occupied_blocks * stat.f_frsize) // src_dev.sectorSize
-
-        # Add 10% just to be on the safe side
-        part_end = last.start + (new_size * 11) // 10
-        # Alighn to 2048
-        part_end = ((part_end + 2047) // 2048) * 2048
-        last = last._replace(end=part_end)
-        partitions[-1] = last
-        
-        # Leave 2048 blocks at the end.
-        new_end = new_size + 2048
-
-        img_disk.setPartitionGeometry(
-            img_disk.getPartitionBySector(last.start),
-            parted.Constraint(device=img_dev), start=last.start, end=last.end)
-        img_disk.commit()
-
-        if last.type == parted.PARTITION_LOGICAL:
-            # Fix the extended partition
-            ext = disk.getExtendedPartition()
-
-            img_disk.setPartitionGeometry(ext,
-                parted.Constraint(device=img_dev), ext.geometry.start,
-                end=last.end)
-            img_disk.commit()
-
-    # Check if we have the available space on the filesystem hosting /mnt
-    # for the image.
-    out.output("Examining available space in /mnt ... ", False)
-    stat = os.statvfs('/mnt')
-    image_size = (new_end + 1) * src_dev.sectorSize
-    available = stat.f_bavail * stat.f_frsize
+    def _mount_options(device):
+        for entry in fstable('/proc/mounts'):
+            if not entry.dev.startswith('/'):
+                continue
 
-    if available <= image_size:
-        raise FatalError('Not enough space in /mnt to host the image')
+            if os.path.realpath(entry.dev) == os.path.realpath(device):
+                return entry
 
-    out.success("sufficient")
+        return
 
-    return img
+    def _create_partition_table(src_disk, dest_file):
+
+        if src_disk.type != 'msdos':
+            raise FatalError('Only msdos partition tables are supported')
+
+        first_sector = src_disk.getPrimaryPartitions()[0].geometry.start
+
+        # Copy the MBR and the space between the MBR and the first partition.
+        # In Grub version 1 Stage 1.5 is located there.
+        first_sector = src_disk.getPrimaryPartitions()[0].geometry.start
+
+        dd('if=%s' % src_disk.device.path, 'of=%s' % dest_file,
+           'bs=%d' % src_disk.device.sectorSize,
+           'count=%d' % first_sector, 'conv=notrunc')
+
+        # Create the Extended boot records (EBRs) in the image
+        extended = src_disk.getExtendedPartition()
+        if not extended:
+            return
+
+        # Extended boot records precede the logical partitions they describe
+        logical = src_disk.getLogicalPartitions()
+        start = extended.geometry.start
+        for i in range(len(logical)):
+            end = logical[i].geometry.start - 1
+            dd('if=%s' % src.device.path, 'of=%s' % dest,
+               'count=%d' % (end - start + 1), 'conv=notrunc',
+               'seek=%d' % start, 'skip=%d' % start)
+            start = logical[i].geometry.end + 1
+
+    def _shrink_partitions(src_disk, image_file):
+
+        partitions = []
+        new_end = 0
+
+        image_dev = parted.Device(image_file)
+        try:
+            image_disk = parted.Disk(image_dev)
+            try:
+                is_extended = lambda p: p.type == parted.PARTITION_EXTENDED
+                is_logical = lambda p: p.type == parted.PARTITION_LOGICAL
+
+                partitions = []
+                for p in src_disk.partitions:
+                    g = p.geometry
+                    f = p.fileSystem
+                    partitions.append(self._Partition(p.number, g.start, g.end,
+                                      p.type, f.type if f is not None else '',
+                                      mount_options(p.path)))
+
+                last = partitions[-1]
+                new_end = src_disk.device.getLength()
+                if last.fs == 'linux-swap(v1)':
+                    MB = 2 ** 20
+                    size = (last.end - last.start + 1) * \
+                        src_disk.device.sectorSize
+                    meta['SWAP'] = "%d:%s" % (last.num, (size + MB - 1) // MB)
+
+                    img_disk.deletePartition(
+                        image_disk.getPartitionBySector(last.start))
+                    img_disk.commit()
+
+                    if is_logical(last) and last.num == 5:
+                        extended = image_disk.getExtendedPartition()
+                        image_disk.deletePartition(extended)
+                        image_disk.commit()
+                        partitions.remove(filter(is_extended, partitions)[0])
+
+                    partitions.remove(last)
+                    last = partitions[-1]
+
+                    # Leave 2048 blocks at the end
+                    new_end = last.end + 2048
+
+                if last.mpoint:
+                    stat = os.statvfs(last.mpoint)
+                    # Shrink the last partition. The new size should be the
+                    # size of the occupied blocks
+                    blcks = stat.f_blocks - stat.f_bavail
+                    new_size = (blcks * stat.f_frsize) // src_dev.sectorSize
+
+                    # Add 10% just to be on the safe side
+                    part_end = last.start + (new_size * 11) // 10
+                    # Alighn to 2048
+                    part_end = ((part_end + 2047) // 2048) * 2048
+                    last = last._replace(end=part_end)
+                    partitions[-1] = last
+
+                    # Leave 2048 blocks at the end.
+                    new_end = new_size + 2048
+
+                    image_disk.setPartitionGeometry(
+                        image_disk.getPartitionBySector(last.start),
+                        parted.Constraint(device=image_disk.device),
+                        start=last.start, end=last.end)
+                    image_disk.commit()
+
+                    if last.type == parted.PARTITION_LOGICAL:
+                        # Fix the extended partition
+                        extended = disk.getExtendedPartition()
+
+                        image_disk.setPartitionGeometry(extended,
+                            parted.Constraint(device=img_dev),
+                            ext.geometry.start, end=last.end)
+                        image_disk.commit()
+            finally:
+                image_disk.destroy()
+        finally:
+            image_dev.destroy()
+
+        # Check if the available space is enough to host the image
+        location = os.path.dirname(image_file)
+        size = (new_end + 1) * src_disk.device.sectorSize
+        self.out.output("Examining available space in %s" % location, False)
+        stat = os.statvfs(location)
+        available = stat.f_bavail * stat.f_frsize
+        if available <= size:
+            raise FatalError('Not enough space in %s to host the image' % \
+                             location)
+        out.success("sufficient")
+
+        return partitions
+
+    def _fill_partitions(src_disk, image, partitions):
+        pass
+
+    def create_image():
+
+        image_file = '/mnt/%s.diskdump' % uuid.uuid4().hex
+
+        src_dev = parted.Device(self.disk)
+        try:
+            size = src_dev.getLength() * src_dev.sectorSize
+
+            # Create sparse file to host the image
+            truncate("-s", "%d" % disk_size, image_file)
+
+            src_disk = parted.Disk(src_dev)
+            try:
+                self._create_partition_table(src_disk, image_file)
+                partitions = self._shrink_partitions(src_disk, image_file)
+                self.fill_partitions(src_disk, image_file, partitions)
+
+            finally:
+                src_disk.destroy()
+        finally:
+            src_dev.destroy()
+
+        return image_file
+
+#      unmounted = filter(lambda p: not p.mopts.mpoint, partitions)
+#        mounted = filter(lambda p: p.mopts.mpoint, partitions)
+#
+#        for p in unmounted:
+#            dd('if=%s' % src_dev.path, 'of=%s' % img_dev.path,
+#               'count=%d' % (p.end - p.start + 1), 'conv=notrunc',
+#                'seek=%d' % p.start, 'skip=%d' % p.start)
+#
+#        partition_devices = create_devices(dest, partitions)
+#
+#        mounted.sort(key=lambda p: p.mopts.mpoint)
+#
+#        return img
 
 # vim: set sta sts=4 shiftwidth=4 sw=4 et ai :