Major code revision

[snf-image-creator] / image_creator / disk.py

diff --git a/image_creator/disk.py b/image_creator/disk.py
index b20ca74..e186174 100644 (file)
--- a/image_creator/disk.py
+++ b/image_creator/disk.py
@@ -6,12 +6,17 @@ import os
 import tempfile
 import uuid
 import re
+import sys
+import guestfs
+
 from pbs import dmsetup
 from pbs import blockdev
 from pbs import dd
-from pbs import kpartx
-from pbs import mount
-from pbs import umount
+
+
+class DiskError(Exception):
+    pass
+
 
 class Disk(object):
 
@@ -33,6 +38,10 @@ class Disk(object):
         raise NotImplementedError
 
     def cleanup(self):
+        while len(self._devices):
+            device = self._devices.pop()
+            device.destroy()
+
         while len(self._cleanup_jobs):
             job, args = self._cleanup_jobs.pop()
             job(*args)
@@ -51,7 +60,8 @@ class Disk(object):
         size = blockdev('--getsize', sourcedev)
         cowfd, cow = tempfile.mkstemp()
         self._add_cleanup(os.unlink, cow)
-        dd('if=/dev/zero', 'of=%s' % cow, 'count=%d' % (1024*1024))#(int(size)/4))
+        # Create 1G cow sparse file
+        dd('if=/dev/null', 'of=%s' % cow, 'bs=1k', 'seek=%d' % (1024 * 1024))
         cowdev = self._losetup(cow)
 
         snapshot = uuid.uuid4().hex
@@ -64,43 +74,96 @@ class Disk(object):
         finally:
             os.unlink(table)
 
-        new_device = DiskDevice(self, "/dev/mapper/%s" % snapshot)
+        new_device = DiskDevice("/dev/mapper/%s" % snapshot)
         self._devices.append(new_device)
         return new_device
 
+    def destroy_device(self, device):
+        self._devices.remove(device)
+        device.destroy()
+
+
 class DiskDevice(object):
 
-    def __init__(self, disk, device):
-        self.disk = disk
-        self.dev = device
-        self.partitions_mapped = False
-        self.magic_number = uuid.uuid4().hex
-
-    def list_partitions(self):
-        output = kpartx("-l", "-p", self.magic_number, self.dev)
-        return [ "/dev/mapper/%s" % x for x in
-                re.findall('^\S+', str(output), flags=re.MULTILINE)]
-
-    def mount(self, partition):
-        if not self.partitions_mapped:
-            kpartx("-a", "-p", self.magic_number, self.dev)
-            self.disk._cleanup_jobs.append(kpartx, "-d", "-p",
-                        self.magic_number, self.dev)
-            self.partitions_mapped = True
-
-        targetfd, target = tempfile.mkdtemp()
-        try:
-            mount(dev, partition)
-        except:
-            os.rmdir(table)
-            raise
-        return target
+    def __init__(self, device, bootable=True):
+        self.device = device
+        self.bootable = bootable
+
+        self.g = guestfs.GuestFS()
+
+        self.g.set_trace(1)
+
+        self.g.add_drive_opts(device, readonly=0)
+        self.g.launch()
+        roots = self.g.inspect_os()
+        if len(roots) == 0:
+            raise DiskError("No operating system found")
+        if len(roots) > 1:
+            raise DiskError("Multiple operating systems found")
+
+        self.root = roots[0]
+        self.ostype = self.g.inspect_get_type(self.root)
+        self.distro = self.g.inspect_get_distro(self.root)
+
+    def destroy(self):
+        self.g.umount_all()
+        self.g.sync()
+        # Close the guestfs handler
+        self.g.close()
+        del self.g
+
+    def mount(self):
+        mps = self.g.inspect_get_mountpoints(self.root)
+
+        # Sort the keys to mount the fs in a correct order.
+        # / should be mounted befor /boot, etc
+        def compare(a, b):
+            if len(a[0]) > len(b[0]):
+                return 1
+            elif len(a[0]) == len(b[0]):
+                return 0
+            else:
+                return -1
+        mps.sort(compare)
+        for mp, dev in mps:
+            try:
+                self.g.mount(dev, mp)
+            except RuntimeError as msg:
+                print "%s (ignored)" % msg
+
+    def umount(self):
+        self.g.umount_all()
+
+    def shrink(self):
+        dev = self.g.part_to_dev(self.root)
+        parttype = self.g.part_get_parttype(dev)
+        if parttype != 'msdos':
+            raise DiskError("You have a %s partition table. "
+                "Only msdos partitions are supported" % parttype)
+
+        last_partition = self.g.part_list(dev)[-1]
+
+        if last_partition['part_num'] > 4:
+            raise DiskError("This disk contains logical partitions. "
+                "Only primary partitions are supported.")
+
+        part_dev = "%s%d" % (dev, last_partition['part_num'])
+        fs_type = self.g.vfs_type(part_dev)
+        if not re.match("ext[234]", fs_type):
+            print "Warning, don't know how to resize %s partitions" % vfs_type
+            return
+
+        self.g.e2fsck_f(part_dev)
+        self.g.resize2fs_M(part_dev)
+        output = self.g.tune2fs_l(part_dev)
+        block_size = int(filter(lambda x: x[0] == 'Block size', output)[0][1])
+        block_cnt = int(filter(lambda x: x[0] == 'Block count', output)[0][1])
+
+        sector_size = self.g.blockdev_getss(dev)
+
+        start = last_partition['part_start'] / sector_size
+        end = start + (block_size * block_cnt) / sector_size - 1
 
-    def unmount(self, partition):
-        umount(target)
 
-        mode = os.stat(self.source).st_mode
-        if stat.S_ISDIR(mode):
-            os.rmdir(target)
 
 # vim: set sta sts=4 shiftwidth=4 sw=4 et ai :