summaryrefslogtreecommitdiffstats
path: root/guestfish.pod
blob: 8ae1800915c3cc42ade92253c4005930ca350aa3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
=encoding utf8

=head1 NAME

guestfish - the libguestfs filesystem interactive shell

=head1 SYNOPSIS

 guestfish [--options] [commands]

 guestfish -i libvirt-domain

 guestfish -i disk-image(s)

=head1 EXAMPLES

=head2 From shell scripts

Create a new C</etc/motd> file in a guest:

 guestfish <<_EOF_
 add disk.img
 run
 mount /dev/VolGroup00/LogVol00 /
 write_file /etc/motd "Hello users" 0
 _EOF_

List the LVs in a guest:

 guestfish <<_EOF_
 add disk.img
 run
 lvs
 _EOF_

=head2 On the command line

List the LVM PVs in a guest image:

 guestfish add disk.img : run : pvs

Remove C</boot/grub/menu.lst> (in reality not such a great idea):

 guestfish --add disk.img \
   --mount /dev/VolGroup00/LogVol00 \
   --mount /dev/sda1:/boot \
   rm /boot/grub/menu.lst

=head2 As an interactive shell

 $ guestfish

 Welcome to guestfish, the libguestfs filesystem interactive shell for
 editing virtual machine filesystems.

 Type: 'help' for help with commands
       'quit' to quit the shell

 ><fs> help

=head2 As a script interpreter

 #!/usr/bin/guestfish -f
 alloc /tmp/output.img 10M
 run
 sfdisk /dev/sda 0 0 0 ,
 mkfs ext2 /dev/sda1

=head2 Remote control

 eval `guestfish --listen`
 guestfish --remote cmd

=head1 DESCRIPTION

Guestfish is a shell and command-line tool for examining and modifying
virtual machine filesystems.  It uses libguestfs and exposes all of
the functionality of the guestfs API, see L<guestfs(3)>.

=head1 OPTIONS

=over 4

=item B<--help>

Displays general help on options.

=item B<-h> | B<--cmd-help>

Lists all available guestfish commands.

=item B<-h cmd> | B<--cmd-help cmd>

Displays detailed help on a single command C<cmd>.

=item B<-a image> | B<--add image>

Add a block device or virtual machine image to the shell.

=item B<-D> | B<--no-dest-paths>

Don't tab-complete paths on the guest filesystem.  It is useful to be
able to hit the tab key to complete paths on the guest filesystem, but
this causes extra "hidden" guestfs calls to be made, so this option is
here to allow this feature to be disabled.

=item B<-f file> | B<--file file>

Read commands from C<file>.  To write pure guestfish
scripts, use:

 #!/usr/bin/guestfish -f

=item B<-i> | B<--inspector>

Run virt-inspector on the named libvirt domain or list of disk
images.  If virt-inspector is available and if it can identify
the domain or disk images, then partitions will be mounted
correctly at start-up.

Typical usage is either:

 guestfish -i myguest

(for an inactive libvirt domain called I<myguest>), or:

 guestfish --ro -i myguest

(for active domains, readonly), or specify the block device directly:

 guestfish -i /dev/Guests/MyGuest

You cannot use I<-a>, I<-m>, I<--listen>, I<--remote> or I<--selinux>
in conjunction with this option, and options other than I<--ro> might
not behave correctly.

See also: L<virt-inspector(1)>.

=item B<--listen>

Fork into the background and listen for remote commands.  See section
I<REMOTE CONTROL GUESTFISH OVER A SOCKET> below.

=item B<-m dev[:mountpoint]> | B<--mount dev[:mountpoint]>

Mount the named partition or logical volume on the given mountpoint.

If the mountpoint is omitted, it defaults to C</>.

You have to mount something on C</> before most commands will work.

If any C<-m> or C<--mount> options are given, the guest is
automatically launched.

=item B<-n> | B<--no-sync>

Disable autosync.  This is enabled by default.  See the discussion
of autosync in the L<guestfs(3)> manpage.

=item B<--remote[=pid]>

Send remote commands to C<$GUESTFISH_PID> or C<pid>.  See section
I<REMOTE CONTROL GUESTFISH OVER A SOCKET> below.

=item B<-r> | B<--ro>

This changes the C<-m> option so that mounts are done read-only
(see C<guestfs_mount_ro> in the L<guestfs(3)> manpage).

=item B<--selinux>

Enable SELinux support for the guest.  See L<guestfs(3)/SELINUX>.

=item B<-v> | B<--verbose>

Enable very verbose messages.  This is particularly useful if you find
a bug.

=item B<-V> | B<--version>

Display the guestfish / libguestfs version number and exit.

=item B<-x>

Echo each command before executing it.

=back

=head1 COMMANDS ON COMMAND LINE

Any additional (non-option) arguments are treated as commands to
execute.

Commands to execute should be separated by a colon (C<:>), where the
colon is a separate parameter.  Thus:

 guestfish cmd [args...] : cmd [args...] : cmd [args...] ...

If there are no additional arguments, then we enter a shell, either an
interactive shell with a prompt (if the input is a terminal) or a
non-interactive shell.

In either command line mode or non-interactive shell, the first
command that gives an error causes the whole shell to exit.  In
interactive mode (with a prompt) if a command fails, you can continue
to enter commands.

=head1 USING launch (OR run)

As with L<guestfs(3)>, you must first configure your guest by adding
disks, then launch it, then mount any disks you need, and finally
issue actions/commands.  So the general order of the day is:

=over 4

=item *

add or -a/--add

=item *

launch (aka run)

=item *

mount or -m/--mount

=item *

any other commands

=back

C<run> is a synonym for C<launch>.  You must C<launch> (or C<run>)
your guest before mounting or performing any other commands.

The only exception is that if the C<-m> or C<--mount> option was
given, the guest is automatically run for you (simply because
guestfish can't mount the disks you asked for without doing this).

=head1 QUOTING

You can quote ordinary parameters using either single or double
quotes.  For example:

 add "file with a space.img"

 rm '/file name'

 rm '/"'

A few commands require a list of strings to be passed.  For these, use
a whitespace-separated list, enclosed in quotes.  Strings containing whitespace
to be passed through must be enclosed in single quotes.  A literal single quote
must be escaped with a backslash.

 vgcreate VG "/dev/sda1 /dev/sdb1"
 command "/bin/echo 'foo      bar'"
 command "/bin/echo \'foo\'"

=head1 WILDCARDS AND GLOBBING

Neither guestfish nor the underlying guestfs API performs
wildcard expansion (globbing) by default.  So for example the
following will not do what you expect:

 rm-rf /home/*

Assuming you don't have a directory literally called C</home/*>
then the above command will return an error.

To perform wildcard expansion, use the C<glob> command.

 glob rm-rf /home/*

runs C<rm-rf> on each path that matches (ie. potentially running
the command many times), equivalent to:

 rm-rf /home/jim
 rm-rf /home/joe
 rm-rf /home/mary

C<glob> only works on simple guest paths and not on device names.

If you have several parameters, each containing a wildcard, then glob
will perform a cartesian product.

=head1 COMMENTS

Any line which starts with a I<#> character is treated as a comment
and ignored.  The I<#> can optionally be preceeded by whitespace,
but B<not> by a command.  For example:

 # this is a comment
         # this is a comment
 foo # NOT a comment

Blank lines are also ignored.

=head1 RUNNING COMMANDS LOCALLY

Any line which starts with a I<!> character is treated as a command
sent to the local shell (C</bin/sh> or whatever L<system(3)> uses).
For example:

 !mkdir local
 tgz-out /remote local/remote-data.tar.gz

will create a directory C<local> on the host, and then export
the contents of C</remote> on the mounted filesystem to
C<local/remote-data.tar.gz>.  (See C<tgz-out>).

=head1 PIPES

Use C<command E<lt>spaceE<gt> | command> to pipe the output of the
first command (a guestfish command) to the second command (any host
command).  For example:

 cat /etc/passwd | awk -F: '$3 == 0 { print }'

(where C<cat> is the guestfish cat command, but C<awk> is the host awk
program).  The above command would list all accounts in the guest
filesystem which have UID 0, ie. root accounts including backdoors.
Other examples:

 hexdump /bin/ls | head
 list-devices | tail -1

The space before the pipe symbol is required, any space after the pipe
symbol is optional.  Everything after the pipe symbol is just passed
straight to the host shell, so it can contain redirections, globs and
anything else that makes sense on the host side.

To use a literal argument which begins with a pipe symbol, you have
to quote it, eg:

 echo "|"

=head1 HOME DIRECTORIES

If a parameter starts with the character C<~> then the tilde may be
expanded as a home directory path (either C<~> for the current user's
home directory, or C<~user> for another user).

Note that home directory expansion happens for users known I<on the
host>, not in the guest filesystem.

To use a literal argument which begins with a tilde, you have to quote
it, eg:

 echo "~"

=head1 WINDOWS PATHS

If a path is prefixed with C<win:> then you can use Windows-style
paths (with some limitations).  The following commands are equivalent:

 file /WINDOWS/system32/config/system.LOG

 file win:/windows/system32/config/system.log

 file win:\windows\system32\config\system.log

 file WIN:C:\Windows\SYSTEM32\conFIG\SYSTEM.LOG

This syntax implicitly calls C<case-sensitive-path> (q.v.) so it also
handles case insensitivity like Windows would.  This only works in
argument positions that expect a path.

=head1 EXIT ON ERROR BEHAVIOUR

By default, guestfish will ignore any errors when in interactive mode
(ie. taking commands from a human over a tty), and will exit on the
first error in non-interactive mode (scripts, commands given on the
command line).

If you prefix a command with a I<-> character, then that command will
not cause guestfish to exit, even if that (one) command returns an
error.

=head1 REMOTE CONTROL GUESTFISH OVER A SOCKET

Guestfish can be remote-controlled over a socket.  This is useful
particularly in shell scripts where you want to make several different
changes to a filesystem, but you don't want the overhead of starting
up a guestfish process each time.

Start a guestfish server process using:

 eval `guestfish --listen`

and then send it commands by doing:

 guestfish --remote cmd [...]

To cause the server to exit, send it the exit command:

 guestfish --remote exit

Note that the server will normally exit if there is an error in a
command.  You can change this in the usual way.  See section I<EXIT ON
ERROR BEHAVIOUR>.

=head2 CONTROLLING MULTIPLE GUESTFISH PROCESSES

The C<eval> statement sets the environment variable C<$GUESTFISH_PID>,
which is how the C<--remote> option knows where to send the commands.
You can have several guestfish listener processes running using:

 eval `guestfish --listen`
 pid1=$GUESTFISH_PID
 eval `guestfish --listen`
 pid2=$GUESTFISH_PID
 ...
 guestfish --remote=$pid1 cmd
 guestfish --remote=$pid2 cmd

=head2 REMOTE CONTROL DETAILS

Remote control happens over a Unix domain socket called
C</tmp/.guestfish-$UID/socket-$PID>, where C<$UID> is the effective
user ID of the process, and C<$PID> is the process ID of the server.

Guestfish client and server versions must match exactly.

=head1 GUESTFISH COMMANDS

The commands in this section are guestfish convenience commands, in
other words, they are not part of the L<guestfs(3)> API.

=head2 alloc | allocate

 alloc filename size

This creates an empty (zeroed) file of the given size, and then adds
so it can be further examined.

For more advanced image creation, see L<qemu-img(1)> utility.

Size can be specified (where C<nn> means a number):

=over 4

=item C<nn> or C<nn>K or C<nn>KB

number of kilobytes, eg: C<1440> = standard 3.5in floppy

=item C<nn>M or C<nn>MB

number of megabytes

=item C<nn>G or C<nn>GB

number of gigabytes

=item C<nn>T or C<nn>TB

number of terabytes

=item C<nn>P or C<nn>PB

number of petabytes

=item C<nn>E or C<nn>EB

number of exabytes

=item C<nn>sects

number of 512 byte sectors

=back

=head2 echo

 echo [params ...]

This echos the parameters to the terminal.

=head2 edit | vi | emacs

 edit filename

This is used to edit a file.  It downloads the file, edits it
locally using your editor, then uploads the result.

The editor is C<$EDITOR>.  However if you use the alternate
commands C<vi> or C<emacs> you will get those corresponding
editors.

NOTE: This will not work reliably for large files
(> 2 MB) or binary files containing \0 bytes.

=head2 glob

 glob command args...

Expand wildcards in any paths in the args list, and run C<command>
repeatedly on each matching path.

See section WILDCARDS AND GLOBBING.

=head2 help

 help
 help cmd

Without any parameter, this lists all commands.  With a C<cmd>
parameter, this displays detailed help for a command.

=head2 lcd

 lcd directory

Change the local directory, ie. the current directory of guestfish
itself.

Note that C<!cd> won't do what you might expect.

=head2 more | less

 more filename

 less filename

This is used to view a file.

The default viewer is C<$PAGER>.  However if you use the alternate
command C<less> you will get the C<less> command specifically.

NOTE: This will not work reliably for large files
(> 2 MB) or binary files containing \0 bytes.

=head2 quit | exit

This exits guestfish.  You can also use C<^D> key.

=head2 reopen

 reopen

Close and reopen the libguestfs handle.  It is not necessary to use
this normally, because the handle is closed properly when guestfish
exits.  However this is occasionally useful for testing.

=head2 sparse

 sparse filename size

This creates an empty sparse file of the given size, and then adds
so it can be further examined.

In all respects it works the same as the C<alloc> command, except that
the image file is allocated sparsely, which means that disk blocks are
not assigned to the file until they are needed.  Sparse disk files
only use space when written to, but they are slower and there is a
danger you could run out of real disk space during a write operation.

For more advanced image creation, see L<qemu-img(1)> utility.

Size can be specified (where C<nn> means a number):

=over 4

=item C<nn> or C<nn>K or C<nn>KB

number of kilobytes, eg: C<1440> = standard 3.5in floppy

=item C<nn>M or C<nn>MB

number of megabytes

=item C<nn>G or C<nn>GB

number of gigabytes

=item C<nn>T or C<nn>TB

number of terabytes

=item C<nn>P or C<nn>PB

number of petabytes

=item C<nn>E or C<nn>EB

number of exabytes

=item C<nn>sects

number of 512 byte sectors

=back

=head2 time

 time command args...

Run the command as usual, but print the elapsed time afterwards.  This
can be useful for benchmarking operations.

=head1 COMMANDS

@ACTIONS@

=head1 ENVIRONMENT VARIABLES

=over 4

=item EDITOR

The C<edit> command uses C<$EDITOR> as the editor.  If not
set, it uses C<vi>.

=item GUESTFISH_PID

Used with the I<--remote> option to specify the remote guestfish
process to control.  See section I<REMOTE CONTROL GUESTFISH OVER A
SOCKET>.

=item HOME

If compiled with GNU readline support, then the command history
is saved in C<$HOME/.guestfish>

=item LIBGUESTFS_APPEND

Pass additional options to the guest kernel.

=item LIBGUESTFS_DEBUG

Set C<LIBGUESTFS_DEBUG=1> to enable verbose messages.  This has the
same effect as using the B<-v> option.

=item LIBGUESTFS_MEMSIZE

Set the memory allocated to the qemu process, in megabytes.  For
example:

 LIBGUESTFS_MEMSIZE=700

=item LIBGUESTFS_PATH

Set the path that guestfish uses to search for kernel and initrd.img.
See the discussion of paths in L<guestfs(3)>.

=item LIBGUESTFS_QEMU

Set the default qemu binary that libguestfs uses.  If not set, then
the qemu which was found at compile time by the configure script is
used.

=item LIBGUESTFS_TRACE

Set C<LIBGUESTFS_TRACE=1> to enable command traces.

=item PAGER

The C<more> command uses C<$PAGER> as the pager.  If not
set, it uses C<more>.

=item TMPDIR

Location of temporary directory, defaults to C</tmp>.

If libguestfs was compiled to use the supermin appliance then each
handle will require rather a large amount of space in this directory
for short periods of time (~ 80 MB).  You can use C<$TMPDIR> to
configure another directory to use in case C</tmp> is not large
enough.

=back

=head1 EXIT CODE

guestfish returns I<0> if the commands completed without error, or
I<1> if there was an error.

=head1 SEE ALSO

L<guestfs(3)>,
L<http://libguestfs.org/>,
L<virt-cat(1)>,
L<virt-edit(1)>,
L<virt-ls(1)>,
L<virt-rescue(1)>,
L<virt-tar(1)>.

=head1 AUTHORS

Richard W.M. Jones (C<rjones at redhat dot com>)

=head1 COPYRIGHT

Copyright (C) 2009 Red Hat Inc.
L<http://libguestfs.org/>

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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.