root / image_creator / disk.py @ e7c01d1e
History | View | Annotate | Download (7.8 kB)
1 | d57775d4 | Nikos Skalkotos | #!/usr/bin/env python
|
---|---|---|---|
2 | d57775d4 | Nikos Skalkotos | |
3 | d57775d4 | Nikos Skalkotos | import losetup |
4 | d57775d4 | Nikos Skalkotos | import stat |
5 | d57775d4 | Nikos Skalkotos | import os |
6 | d57775d4 | Nikos Skalkotos | import tempfile |
7 | d57775d4 | Nikos Skalkotos | import uuid |
8 | d57775d4 | Nikos Skalkotos | import re |
9 | 1377b8a7 | Nikos Skalkotos | import sys |
10 | 1377b8a7 | Nikos Skalkotos | import guestfs |
11 | 1377b8a7 | Nikos Skalkotos | |
12 | 01a7cff3 | Nikos Skalkotos | import pbs |
13 | d57775d4 | Nikos Skalkotos | from pbs import dd |
14 | 586da0a0 | Nikos Skalkotos | from clint.textui import progress |
15 | 1377b8a7 | Nikos Skalkotos | |
16 | 8c574358 | Nikos Skalkotos | |
17 | 8c574358 | Nikos Skalkotos | class DiskError(Exception): |
18 | 8c574358 | Nikos Skalkotos | pass
|
19 | 8c574358 | Nikos Skalkotos | |
20 | d57775d4 | Nikos Skalkotos | |
21 | 01a7cff3 | Nikos Skalkotos | def find_sbin_command(command, exception): |
22 | 01a7cff3 | Nikos Skalkotos | search_paths = ['/usr/local/sbin', '/usr/sbin', '/sbin'] |
23 | 01a7cff3 | Nikos Skalkotos | for fullpath in map(lambda x: "%s/%s" % (x, command), search_paths): |
24 | 01a7cff3 | Nikos Skalkotos | if os.path.exists(fullpath) and os.access(fullpath, os.X_OK): |
25 | 01a7cff3 | Nikos Skalkotos | return pbs.Command(fullpath)
|
26 | 01a7cff3 | Nikos Skalkotos | continue
|
27 | 01a7cff3 | Nikos Skalkotos | raise exception
|
28 | 01a7cff3 | Nikos Skalkotos | |
29 | 01a7cff3 | Nikos Skalkotos | |
30 | 01a7cff3 | Nikos Skalkotos | try:
|
31 | 01a7cff3 | Nikos Skalkotos | from pbs import dmsetup |
32 | 01a7cff3 | Nikos Skalkotos | except pbs.CommandNotFound as e: |
33 | 01a7cff3 | Nikos Skalkotos | dmsetup = find_sbin_command('dmsetup', e)
|
34 | 01a7cff3 | Nikos Skalkotos | |
35 | 01a7cff3 | Nikos Skalkotos | try:
|
36 | 01a7cff3 | Nikos Skalkotos | from pbs import blockdev |
37 | 01a7cff3 | Nikos Skalkotos | except pbs.CommandNotFound as e: |
38 | 01a7cff3 | Nikos Skalkotos | blockdev = find_sbin_command('blockdev', e)
|
39 | 01a7cff3 | Nikos Skalkotos | |
40 | 01a7cff3 | Nikos Skalkotos | |
41 | d57775d4 | Nikos Skalkotos | class Disk(object): |
42 | 3b2f6619 | Nikos Skalkotos | """This class represents a hard disk hosting an Operating System
|
43 | 3b2f6619 | Nikos Skalkotos |
|
44 | 3b2f6619 | Nikos Skalkotos | A Disk instance never alters the source media it is created from.
|
45 | 3b2f6619 | Nikos Skalkotos | Any change is done on a snapshot created by the device-mapper of
|
46 | 3b2f6619 | Nikos Skalkotos | the Linux kernel.
|
47 | 3b2f6619 | Nikos Skalkotos | """
|
48 | d57775d4 | Nikos Skalkotos | |
49 | d57775d4 | Nikos Skalkotos | def __init__(self, source): |
50 | 3b2f6619 | Nikos Skalkotos | """Create a new Disk instance out of a source media. The source
|
51 | 3b2f6619 | Nikos Skalkotos | media can be an image file, a block device or a directory."""
|
52 | d57775d4 | Nikos Skalkotos | self._cleanup_jobs = []
|
53 | d57775d4 | Nikos Skalkotos | self._devices = []
|
54 | d57775d4 | Nikos Skalkotos | self.source = source
|
55 | d57775d4 | Nikos Skalkotos | |
56 | d57775d4 | Nikos Skalkotos | def _add_cleanup(self, job, *args): |
57 | d57775d4 | Nikos Skalkotos | self._cleanup_jobs.append((job, args))
|
58 | d57775d4 | Nikos Skalkotos | |
59 | d57775d4 | Nikos Skalkotos | def _losetup(self, fname): |
60 | d57775d4 | Nikos Skalkotos | loop = losetup.find_unused_loop_device() |
61 | d57775d4 | Nikos Skalkotos | loop.mount(fname) |
62 | d57775d4 | Nikos Skalkotos | self._add_cleanup(loop.unmount)
|
63 | d57775d4 | Nikos Skalkotos | return loop.device
|
64 | d57775d4 | Nikos Skalkotos | |
65 | d57775d4 | Nikos Skalkotos | def _dir_to_disk(self): |
66 | d57775d4 | Nikos Skalkotos | raise NotImplementedError |
67 | d57775d4 | Nikos Skalkotos | |
68 | d57775d4 | Nikos Skalkotos | def cleanup(self): |
69 | 3b2f6619 | Nikos Skalkotos | """Cleanup internal data. This needs to be called before the
|
70 | 3b2f6619 | Nikos Skalkotos | program ends.
|
71 | 3b2f6619 | Nikos Skalkotos | """
|
72 | 1377b8a7 | Nikos Skalkotos | while len(self._devices): |
73 | 1377b8a7 | Nikos Skalkotos | device = self._devices.pop()
|
74 | 1377b8a7 | Nikos Skalkotos | device.destroy() |
75 | 8c574358 | Nikos Skalkotos | |
76 | d57775d4 | Nikos Skalkotos | while len(self._cleanup_jobs): |
77 | d57775d4 | Nikos Skalkotos | job, args = self._cleanup_jobs.pop()
|
78 | d57775d4 | Nikos Skalkotos | job(*args) |
79 | d57775d4 | Nikos Skalkotos | |
80 | d57775d4 | Nikos Skalkotos | def get_device(self): |
81 | 3b2f6619 | Nikos Skalkotos | """Returns a newly created DiskDevice instance.
|
82 | c408053f | Nikos Skalkotos |
|
83 | 3b2f6619 | Nikos Skalkotos | This instance is a snapshot of the original source media of
|
84 | 3b2f6619 | Nikos Skalkotos | the Disk instance.
|
85 | 3b2f6619 | Nikos Skalkotos | """
|
86 | d57775d4 | Nikos Skalkotos | sourcedev = self.source
|
87 | d57775d4 | Nikos Skalkotos | mode = os.stat(self.source).st_mode
|
88 | d57775d4 | Nikos Skalkotos | if stat.S_ISDIR(mode):
|
89 | d57775d4 | Nikos Skalkotos | return self._losetup(self._dir_to_disk()) |
90 | d57775d4 | Nikos Skalkotos | elif stat.S_ISREG(mode):
|
91 | d57775d4 | Nikos Skalkotos | sourcedev = self._losetup(self.source) |
92 | d57775d4 | Nikos Skalkotos | elif not stat.S_ISBLK(mode): |
93 | d57775d4 | Nikos Skalkotos | raise ValueError("Value for self.source is invalid") |
94 | d57775d4 | Nikos Skalkotos | |
95 | d57775d4 | Nikos Skalkotos | # Take a snapshot and return it to the user
|
96 | d57775d4 | Nikos Skalkotos | size = blockdev('--getsize', sourcedev)
|
97 | d57775d4 | Nikos Skalkotos | cowfd, cow = tempfile.mkstemp() |
98 | d57775d4 | Nikos Skalkotos | self._add_cleanup(os.unlink, cow)
|
99 | 8c574358 | Nikos Skalkotos | # Create 1G cow sparse file
|
100 | 8c574358 | Nikos Skalkotos | dd('if=/dev/null', 'of=%s' % cow, 'bs=1k', 'seek=%d' % (1024 * 1024)) |
101 | d57775d4 | Nikos Skalkotos | cowdev = self._losetup(cow)
|
102 | d57775d4 | Nikos Skalkotos | |
103 | d57775d4 | Nikos Skalkotos | snapshot = uuid.uuid4().hex |
104 | d57775d4 | Nikos Skalkotos | tablefd, table = tempfile.mkstemp() |
105 | d57775d4 | Nikos Skalkotos | try:
|
106 | d57775d4 | Nikos Skalkotos | os.write(tablefd, "0 %d snapshot %s %s n 8" % \
|
107 | d57775d4 | Nikos Skalkotos | (int(size), sourcedev, cowdev))
|
108 | d57775d4 | Nikos Skalkotos | dmsetup('create', snapshot, table)
|
109 | d57775d4 | Nikos Skalkotos | self._add_cleanup(dmsetup, 'remove', snapshot) |
110 | d57775d4 | Nikos Skalkotos | finally:
|
111 | d57775d4 | Nikos Skalkotos | os.unlink(table) |
112 | d57775d4 | Nikos Skalkotos | |
113 | 1377b8a7 | Nikos Skalkotos | new_device = DiskDevice("/dev/mapper/%s" % snapshot)
|
114 | d57775d4 | Nikos Skalkotos | self._devices.append(new_device)
|
115 | d57775d4 | Nikos Skalkotos | return new_device
|
116 | d57775d4 | Nikos Skalkotos | |
117 | 1377b8a7 | Nikos Skalkotos | def destroy_device(self, device): |
118 | 3b2f6619 | Nikos Skalkotos | """Destroys a DiskDevice instance previously created by
|
119 | 3b2f6619 | Nikos Skalkotos | get_device method.
|
120 | 3b2f6619 | Nikos Skalkotos | """
|
121 | 1377b8a7 | Nikos Skalkotos | self._devices.remove(device)
|
122 | 1377b8a7 | Nikos Skalkotos | device.destroy() |
123 | 1377b8a7 | Nikos Skalkotos | |
124 | 8c574358 | Nikos Skalkotos | |
125 | 586da0a0 | Nikos Skalkotos | def progress_generator(total): |
126 | 586da0a0 | Nikos Skalkotos | position = 0;
|
127 | 586da0a0 | Nikos Skalkotos | for i in progress.bar(range(total)): |
128 | 586da0a0 | Nikos Skalkotos | if i < position:
|
129 | 586da0a0 | Nikos Skalkotos | continue
|
130 | 586da0a0 | Nikos Skalkotos | position = yield
|
131 | e7c01d1e | Nikos Skalkotos | yield #suppress the StopIteration exception |
132 | 586da0a0 | Nikos Skalkotos | |
133 | 586da0a0 | Nikos Skalkotos | |
134 | d57775d4 | Nikos Skalkotos | class DiskDevice(object): |
135 | 3b2f6619 | Nikos Skalkotos | """This class represents a block device hosting an Operating System
|
136 | 3b2f6619 | Nikos Skalkotos | as created by the device-mapper.
|
137 | 3b2f6619 | Nikos Skalkotos | """
|
138 | d57775d4 | Nikos Skalkotos | |
139 | 8c574358 | Nikos Skalkotos | def __init__(self, device, bootable=True): |
140 | 3b2f6619 | Nikos Skalkotos | """Create a new DiskDevice."""
|
141 | 333ff548 | Nikos Skalkotos | self.device = device
|
142 | 1377b8a7 | Nikos Skalkotos | self.bootable = bootable
|
143 | 586da0a0 | Nikos Skalkotos | self.progress_bar = None |
144 | 1377b8a7 | Nikos Skalkotos | |
145 | 1377b8a7 | Nikos Skalkotos | self.g = guestfs.GuestFS()
|
146 | 586da0a0 | Nikos Skalkotos | self.g.add_drive_opts(device, readonly=0) |
147 | 0d5a999d | Nikos Skalkotos | |
148 | 586da0a0 | Nikos Skalkotos | #self.g.set_trace(1)
|
149 | 586da0a0 | Nikos Skalkotos | #self.g.set_verbose(1)
|
150 | 0d5a999d | Nikos Skalkotos | |
151 | 586da0a0 | Nikos Skalkotos | eh = self.g.set_event_callback(self.progress_callback, guestfs.EVENT_PROGRESS) |
152 | 1377b8a7 | Nikos Skalkotos | self.g.launch()
|
153 | 586da0a0 | Nikos Skalkotos | self.g.delete_event_callback(eh)
|
154 | 586da0a0 | Nikos Skalkotos | |
155 | 1377b8a7 | Nikos Skalkotos | roots = self.g.inspect_os()
|
156 | 1377b8a7 | Nikos Skalkotos | if len(roots) == 0: |
157 | 1377b8a7 | Nikos Skalkotos | raise DiskError("No operating system found") |
158 | 1377b8a7 | Nikos Skalkotos | if len(roots) > 1: |
159 | 1377b8a7 | Nikos Skalkotos | raise DiskError("Multiple operating systems found") |
160 | 1377b8a7 | Nikos Skalkotos | |
161 | 1377b8a7 | Nikos Skalkotos | self.root = roots[0] |
162 | aa2062ba | Nikos Skalkotos | self.ostype = self.g.inspect_get_type(self.root) |
163 | aa2062ba | Nikos Skalkotos | self.distro = self.g.inspect_get_distro(self.root) |
164 | 8c574358 | Nikos Skalkotos | |
165 | 1377b8a7 | Nikos Skalkotos | def destroy(self): |
166 | 3b2f6619 | Nikos Skalkotos | """Destroy this DiskDevice instance."""
|
167 | 1377b8a7 | Nikos Skalkotos | self.g.umount_all()
|
168 | 1377b8a7 | Nikos Skalkotos | self.g.sync()
|
169 | 1377b8a7 | Nikos Skalkotos | # Close the guestfs handler
|
170 | aa2062ba | Nikos Skalkotos | self.g.close()
|
171 | 8c574358 | Nikos Skalkotos | |
172 | 586da0a0 | Nikos Skalkotos | def progress_callback(self, ev, eh, buf, array): |
173 | 586da0a0 | Nikos Skalkotos | position = array[2]
|
174 | 586da0a0 | Nikos Skalkotos | total = array[3]
|
175 | 586da0a0 | Nikos Skalkotos | |
176 | 586da0a0 | Nikos Skalkotos | if self.progress_bar is None: |
177 | 586da0a0 | Nikos Skalkotos | self.progress_bar = progress_generator(total)
|
178 | 586da0a0 | Nikos Skalkotos | self.progress_bar.next()
|
179 | 586da0a0 | Nikos Skalkotos | |
180 | 586da0a0 | Nikos Skalkotos | self.progress_bar.send(position)
|
181 | 586da0a0 | Nikos Skalkotos | |
182 | 586da0a0 | Nikos Skalkotos | if position == total:
|
183 | 586da0a0 | Nikos Skalkotos | self.progress_bar = None |
184 | 586da0a0 | Nikos Skalkotos | |
185 | 1377b8a7 | Nikos Skalkotos | def mount(self): |
186 | 3b2f6619 | Nikos Skalkotos | """Mount all disk partitions in a correct order."""
|
187 | 0d5a999d | Nikos Skalkotos | mps = self.g.inspect_get_mountpoints(self.root) |
188 | 8c574358 | Nikos Skalkotos | |
189 | 1377b8a7 | Nikos Skalkotos | # Sort the keys to mount the fs in a correct order.
|
190 | 1377b8a7 | Nikos Skalkotos | # / should be mounted befor /boot, etc
|
191 | 8c574358 | Nikos Skalkotos | def compare(a, b): |
192 | 8c574358 | Nikos Skalkotos | if len(a[0]) > len(b[0]): |
193 | 8c574358 | Nikos Skalkotos | return 1 |
194 | 8c574358 | Nikos Skalkotos | elif len(a[0]) == len(b[0]): |
195 | 8c574358 | Nikos Skalkotos | return 0 |
196 | 8c574358 | Nikos Skalkotos | else:
|
197 | 8c574358 | Nikos Skalkotos | return -1 |
198 | 1377b8a7 | Nikos Skalkotos | mps.sort(compare) |
199 | 1377b8a7 | Nikos Skalkotos | for mp, dev in mps: |
200 | 1377b8a7 | Nikos Skalkotos | try:
|
201 | 1377b8a7 | Nikos Skalkotos | self.g.mount(dev, mp)
|
202 | 1377b8a7 | Nikos Skalkotos | except RuntimeError as msg: |
203 | 1377b8a7 | Nikos Skalkotos | print "%s (ignored)" % msg |
204 | d57775d4 | Nikos Skalkotos | |
205 | 8c574358 | Nikos Skalkotos | def umount(self): |
206 | 3b2f6619 | Nikos Skalkotos | """Umount all mounted filesystems."""
|
207 | 8c574358 | Nikos Skalkotos | self.g.umount_all()
|
208 | 8c574358 | Nikos Skalkotos | |
209 | 8c574358 | Nikos Skalkotos | def shrink(self): |
210 | 3b2f6619 | Nikos Skalkotos | """Shrink the disk.
|
211 | 3b2f6619 | Nikos Skalkotos |
|
212 | 3b2f6619 | Nikos Skalkotos | This is accomplished by shrinking the last filesystem in the
|
213 | 3b2f6619 | Nikos Skalkotos | disk and then updating the partition table. The new disk size
|
214 | 3b2f6619 | Nikos Skalkotos | (in bytes) is returned.
|
215 | 3b2f6619 | Nikos Skalkotos | """
|
216 | 8c574358 | Nikos Skalkotos | dev = self.g.part_to_dev(self.root) |
217 | 8c574358 | Nikos Skalkotos | parttype = self.g.part_get_parttype(dev)
|
218 | 8c574358 | Nikos Skalkotos | if parttype != 'msdos': |
219 | 8c574358 | Nikos Skalkotos | raise DiskError("You have a %s partition table. " |
220 | 8c574358 | Nikos Skalkotos | "Only msdos partitions are supported" % parttype)
|
221 | 8c574358 | Nikos Skalkotos | |
222 | 8c574358 | Nikos Skalkotos | last_partition = self.g.part_list(dev)[-1] |
223 | 8c574358 | Nikos Skalkotos | |
224 | 8c574358 | Nikos Skalkotos | if last_partition['part_num'] > 4: |
225 | 8c574358 | Nikos Skalkotos | raise DiskError("This disk contains logical partitions. " |
226 | 8c574358 | Nikos Skalkotos | "Only primary partitions are supported.")
|
227 | 8c574358 | Nikos Skalkotos | |
228 | 8c574358 | Nikos Skalkotos | part_dev = "%s%d" % (dev, last_partition['part_num']) |
229 | 8c574358 | Nikos Skalkotos | fs_type = self.g.vfs_type(part_dev)
|
230 | 8c574358 | Nikos Skalkotos | if not re.match("ext[234]", fs_type): |
231 | a1a5ca4b | Nikos Skalkotos | print "Warning: Don't know how to resize %s partitions." % vfs_type |
232 | 8c574358 | Nikos Skalkotos | return
|
233 | 8c574358 | Nikos Skalkotos | |
234 | 8c574358 | Nikos Skalkotos | self.g.e2fsck_f(part_dev)
|
235 | 8c574358 | Nikos Skalkotos | self.g.resize2fs_M(part_dev)
|
236 | 8c574358 | Nikos Skalkotos | output = self.g.tune2fs_l(part_dev)
|
237 | 8c574358 | Nikos Skalkotos | block_size = int(filter(lambda x: x[0] == 'Block size', output)[0][1]) |
238 | 8c574358 | Nikos Skalkotos | block_cnt = int(filter(lambda x: x[0] == 'Block count', output)[0][1]) |
239 | 8c574358 | Nikos Skalkotos | |
240 | 8c574358 | Nikos Skalkotos | sector_size = self.g.blockdev_getss(dev)
|
241 | 8c574358 | Nikos Skalkotos | |
242 | 8c574358 | Nikos Skalkotos | start = last_partition['part_start'] / sector_size
|
243 | 8c574358 | Nikos Skalkotos | end = start + (block_size * block_cnt) / sector_size - 1
|
244 | 8c574358 | Nikos Skalkotos | |
245 | c408053f | Nikos Skalkotos | self.g.part_del(dev, last_partition['part_num']) |
246 | c408053f | Nikos Skalkotos | self.g.part_add(dev, 'p', start, end) |
247 | c408053f | Nikos Skalkotos | |
248 | e3aac3f9 | Nikos Skalkotos | return (end + 1) * sector_size |
249 | e3aac3f9 | Nikos Skalkotos | |
250 | c408053f | Nikos Skalkotos | def size(self): |
251 | c408053f | Nikos Skalkotos | """Returns the "payload" size of the device.
|
252 | c408053f | Nikos Skalkotos |
|
253 | c408053f | Nikos Skalkotos | The size returned by this method is the size of the space occupied by
|
254 | c408053f | Nikos Skalkotos | the partitions (including the space before the first partition).
|
255 | c408053f | Nikos Skalkotos | """
|
256 | c408053f | Nikos Skalkotos | dev = self.g.part_to_dev(self.root) |
257 | c408053f | Nikos Skalkotos | last = self.g.part_list(dev)[-1] |
258 | c408053f | Nikos Skalkotos | |
259 | c408053f | Nikos Skalkotos | return last['part_end'] |
260 | 8c574358 | Nikos Skalkotos | |
261 | d57775d4 | Nikos Skalkotos | # vim: set sta sts=4 shiftwidth=4 sw=4 et ai : |