1virt-builder(1) Virtualization Support virt-builder(1)
2
6 virt-builder - Build virtual machine images quickly
7
9 virt-builder os-version
10 [-o|--output DISKIMAGE] [--size SIZE] [--format raw|qcow2]
11 [--arch ARCHITECTURE] [--attach ISOFILE]
12 [--append-line FILE:LINE] [--chmod PERMISSIONS:FILE]
13 [--commands-from-file FILENAME] [--copy SOURCE:DEST]
14 [--copy-in LOCALPATH:REMOTEDIR] [--delete PATH] [--edit FILE:EXPR]
15 [--firstboot SCRIPT] [--firstboot-command 'CMD+ARGS']
16 [--firstboot-install PKG,PKG..] [--hostname HOSTNAME]
17 [--install PKG,PKG..] [--link TARGET:LINK[:LINK..]] [--mkdir DIR]
18 [--move SOURCE:DEST] [--password USER:SELECTOR]
19 [--root-password SELECTOR] [--run SCRIPT]
20 [--run-command 'CMD+ARGS'] [--scrub FILE] [--sm-attach SELECTOR]
21 [--sm-register] [--sm-remove] [--sm-unregister]
22 [--ssh-inject USER[:SELECTOR]] [--truncate FILE]
23 [--truncate-recursive PATH] [--timezone TIMEZONE] [--touch FILE]
24 [--uninstall PKG,PKG..] [--update] [--upload FILE:DEST]
25 [--write FILE:CONTENT] [--no-logfile]
26 [--password-crypto md5|sha256|sha512] [--selinux-relabel]
27 [--sm-credentials SELECTOR]
28 virt-builder -l|--list [--long] [--list-format short|long|json] [os-version]
31 virt-builder --notes os-version
33 virt-builder --print-cache
35 virt-builder --cache-all-templates
37 virt-builder --delete-cache
39 virt-builder --get-kernel DISKIMAGE
41 [--format raw|qcow2] [--output OUTPUTDIR]
42
44 Virt-builder is a tool for quickly building new virtual machines. You
45 can build a variety of VMs for local or cloud use, usually within a few
46 minutes or less. Virt-builder also has many ways to customize these
47 VMs. Everything is run from the command line and nothing requires root
48 privileges, so automation and scripting is simple.
49 Note that virt-builder does not install guests from scratch. It takes
51 cleanly prepared, digitally signed OS templates and customizes them.
52 This approach is used because it is much faster, but if you need to do
53 fresh installs you may want to look at virt-install(1) and
54 oz-install(1).
55 The easiest way to get started is by looking at the examples in the
57 next section.
58
60 List the virtual machines available
61 virt-builder --list
62 will list out the operating systems available to install. A selection
64 of freely redistributable OSes is available as standard. You can add
65 your own too (see below).
66 After choosing a guest from the list, you may want to see if there are
68 any installation notes:
69 virt-builder --notes fedora-27
71 Build a virtual machine
73 virt-builder fedora-27
74 will build a Fedora 25 image for the same architecture as virt-builder
76 (so running it from an i686 installation will try to build an i686
77 image, if available). This will have all default configuration
78 (minimal size, no user accounts, random root password, only the bare
79 minimum installed software, etc.).
80 You do not need to run this command as root.
82 The first time this runs it has to download the template over the
84 network, but this gets cached (see "CACHING").
85 The name of the output file is derived from the template name, so above
87 it will be fedora-27.img. You can change the output filename using the
88 -o option:
89 virt-builder fedora-27 -o mydisk.img
91 You can also use the -o option to write to existing devices or logical
93 volumes.
94 virt-builder fedora-27 --format qcow2
96 As above, but write the output in qcow2 format to fedora-27.qcow2.
98 virt-builder fedora-27 --size 20G
100 As above, but the output size will be 20 GB. The guest OS is resized
102 as it is copied to the output (automatically, using virt-resize(1)).
103 virt-builder fedora-27 --arch i686
105 As above, but using an i686 template, if available.
107 Setting the root password
109 virt-builder fedora-27 --root-password file:/tmp/rootpw
110 Create a Fedora 25 image. The root password is taken from the file
112 /tmp/rootpw.
113 Note if you don’t set --root-password then the guest is given a random
115 root password which is printed on stdout.
116 You can also create user accounts. See "USERS AND PASSWORDS" below.
118 Set the hostname
120 virt-builder fedora-27 --hostname virt.example.com
121 Set the hostname to "virt.example.com".
123 Installing software
125 To install packages from the ordinary (guest) software repository (eg.
126 dnf or apt):
127 virt-builder fedora-27 --install "inkscape,@Xfce Desktop"
129 (In Fedora, "@" is used to install groups of packages. On Debian you
131 would install a meta-package instead.)
132 To update the installed packages to the latest version:
134 virt-builder debian-7 --update
136 For guests which use SELinux, like Fedora and Red Hat Enterprise Linux,
138 you may need to do SELinux relabelling after installing or updating
139 packages (see "SELINUX" below):
140 virt-builder fedora-27 --update --selinux-relabel
142 Customizing the installation
144 There are many options that let you customize the installation. These
145 include: --run/--run-command, which run a shell script or command while
146 the disk image is being generated and lets you add or edit files that
147 go into the disk image. --firstboot/--firstboot-command, which let you
148 add scripts/commands that are run the first time the guest boots.
149 --edit to edit files. --upload to upload files.
150 For example:
152 cat <<'EOF' > /tmp/dnf-update.sh
154 dnf -y --best update
155 EOF
156 virt-builder fedora-27 --firstboot /tmp/dnf-update.sh
158 or simply:
160 virt-builder fedora-27 --firstboot-command 'dnf -y --best update'
162 which makes the dnf(8) "update" command run once the first time the
164 guest boots.
165 Or:
167 virt-builder fedora-27 \
169 --edit '/etc/dnf/dnf.conf:
170 s/gpgcheck=1/gpgcheck=0/'
171 which edits /etc/dnf/dnf.conf inside the disk image (during disk image
173 creation, long before boot).
174 You can combine these options, and have multiple options of all types.
176
178 --help
179 Display help.
180 --arch ARCHITECTURE
182 Use the specified architecture for the output image. This means
183 there must be sources providing the requested template for the
184 requested architecture.
185 See also "ARCHITECTURE".
187 --attach ISOFILE
189 During the customization phase, the given disk is attached to the
190 libguestfs appliance. This is used to provide extra software
191 repositories or other data for customization.
192 You probably want to ensure the volume(s) or filesystems in the
194 attached disks are labelled (or use an ISO volume name) so that you
195 can mount them by label in your run-scripts:
196 mkdir /tmp/mount
198 mount LABEL=EXTRA /tmp/mount
199 You can have multiple --attach options, and the format can be any
201 disk format (not just an ISO).
202 See also: --run, "Installing packages at build time from a side
204 repository", genisoimage(1), virt-make-fs(1).
205 --attach-format FORMAT
207 Specify the disk format for the next --attach option. The "FORMAT"
208 is usually "raw" or "qcow2". Use "raw" for ISOs.
209 --cache DIR
211 --no-cache
212 --cache DIR sets the directory to use/check for cached template
213 files. If not set, defaults to either
214 $XDG_CACHE_HOME/virt-builder/ or $HOME/.cache/virt-builder/.
215 --no-cache disables template caching.
217 --cache-all-templates
219 Download all templates to the cache and then exit. See "CACHING".
220 Note this doesn't cache everything. More templates might be
222 uploaded. Also this doesn't cache packages (the --install,
223 --update options).
224 --check-signature
226 --no-check-signature
227 Check/don’t check the digital signature of the OS template. The
228 default is to check the signature and exit if it is not correct.
229 Using --no-check-signature bypasses this check.
230 See also --fingerprint.
232 --colors
234 --colours
235 Use ANSI colour sequences to colourize messages. This is the
236 default when the output is a tty. If the output of the program is
237 redirected to a file, ANSI colour sequences are disabled unless you
238 use this option.
239 --curl CURL
241 Specify an alternate curl(1) binary. You can also use this to add
242 curl parameters, for example to disable https certificate checks:
243 virt-builder --curl "curl --insecure" [...]
245 --delete-cache
247 Delete the template cache. See "CACHING".
248 --no-delete-on-failure
250 Don’t delete the output file on failure to build. You can use this
251 to debug failures to run scripts. See "DEBUGGING BUILDS" for ways
252 to debug images.
253 The default is to delete the output file if virt-builder fails (or,
255 for example, some script that it runs fails).
256 --fingerprint 'AAAA BBBB ...'
258 Check that the index and templates are signed by the key with the
259 given fingerprint. (The fingerprint is a long string, usually
260 written as 10 groups of 4 hexadecimal digits).
261 You can give this option multiple times. If you have multiple
263 source URLs, then you can have either no fingerprint, one
264 fingerprint or multiple fingerprints. If you have multiple, then
265 each must correspond 1-1 with a source URL.
266 --format qcow2
268 --format raw
269 For ordinary builds, this selects the output format. The default
270 is raw.
271 With --get-kernel this specifies the input format.
273 To create an old-style qcow2 file (for compatibility with RHEL 6 or
275 very old qemu < 1.1), after running virt-builder, use this command:
276 qemu-img amend -f qcow2 -o compat=0.10 output.qcow2
278 --get-kernel IMAGE
280 This option extracts the kernel and initramfs from a previously
281 built disk image called "IMAGE" (in fact it works for any VM disk
282 image, not just ones built using virt-builder).
283 Note this method is deprecated: there is a separate tool for this,
285 virt-get-kernel(1), which has more options for the file extraction.
286 The kernel and initramfs are written to the current directory,
288 unless you also specify the --output "outputdir" directory name.
289 The format of the disk image is automatically detected unless you
291 specify it by using the --format option.
292 In the case where the guest contains multiple kernels, the one with
294 the highest version number is chosen. To extract arbitrary kernels
295 from the disk image, see guestfish(1). To extract the entire /boot
296 directory of a guest, see virt-copy-out(1).
297 --gpg GPG
299 Specify an alternate gpg(1) (GNU Privacy Guard) binary. By default
300 virt-builder looks for either "gpg2" or "gpg" in the $PATH.
301 You can also use this to add gpg parameters, for example to specify
303 an alternate home directory:
304 virt-builder --gpg "gpg --homedir /tmp" [...]
306 -l [os-version]
308 --list [os-version]
309 --list --list-format format [os-version]
310 --list --long [os-version]
311 List all the available templates if no guest is specified, or only
312 for the specified one.
313 It is possible to choose with --list-format the output format for
315 the list templates:
316 short
318 The default format, prints only the template identifier and,
319 next to it, its short description.
320 long
322 Prints a textual list with the details of the available
323 sources, followed by the details of the available templates.
324 json
326 Prints a JSON object with the details of the available sources
327 and the details of the available templates.
328 The "version" key in the main object represents the
330 "compatibility version", and it is bumped every time the
331 resulting JSON output is incompatible with the previous
332 versions (for example the structure has changed, or non-
333 optional keys are no more present).
334 --long is a shorthand for the "long" format.
336 See also: --source, --notes, "SOURCES OF TEMPLATES".
338 --machine-readable
340 --machine-readable=format
341 This option is used to make the output more machine friendly when
342 being parsed by other programs. See "MACHINE READABLE OUTPUT"
343 below.
344 -m MB
346 --memsize MB
347 Change the amount of memory allocated to --run scripts. Increase
348 this if you find that --run scripts or the --install option are
349 running out of memory.
350 The default can be found with this command:
352 guestfish get-memsize
354 --network
356 --no-network
357 Enable or disable network access from the guest during the
358 installation.
359 Enabled is the default. Use --no-network to disable access.
361 The network only allows outgoing connections and has other minor
363 limitations. See "NETWORK" in virt-rescue(1).
364 If you use --no-network then certain other options such as
366 --install will not work.
367 This does not affect whether the guest can access the network once
369 it has been booted, because that is controlled by your hypervisor
370 or cloud environment and has nothing to do with virt-builder.
371 Generally speaking you should not use --no-network. But here are
373 some reasons why you might want to:
374 1. Because the libguestfs backend that you are using doesn't
376 support the network. (See: "BACKEND" in guestfs(3)).
377 2. Any software you need to install comes from an attached ISO, so
379 you don't need the network.
380 3. You don’t want untrusted guest code trying to access your host
382 network when running virt-builder. This is particularly an
383 issue when you don't trust the source of the operating system
384 templates. (See "SECURITY" below).
385 4. You don’t have a host network (eg. in secure/restricted
387 environments).
388 --no-sync
390 Do not sync the output file on exit.
391 Virt-builder "fsync"s the output file or disk image when it exits.
393 The reason is that qemu/KVM’s default caching mode is "none" or
395 "directsync", both of which bypass the host page cache. Therefore
396 these would not work correctly if you immediately started the guest
397 after running virt-builder - they would not see the complete output
398 file. (Note that you should not use these caching modes - they are
399 fundamentally broken for this and other reasons.)
400 If you are not using these broken caching modes, you can use
402 --no-sync to avoid this unnecessary sync and gain considerable
403 extra performance.
404 --notes os-version
406 List any notes associated with this guest, then exit (this does not
407 do the install).
408 -o filename
410 --output filename
411 Write the output to filename. If you don’t specify this option,
412 then the output filename is generated by taking the "os-version"
413 string and adding ".img" (for raw format) or ".qcow2" (for qcow2
414 format).
415 Note that the output filename could be a device, partition or
417 logical volume.
418 When used with --get-kernel, this option specifies the output
420 directory.
421 --print-cache
423 Print information about the template cache. See "CACHING".
424 -q
426 --quiet
427 Don’t print ordinary progress messages.
428 --size SIZE
430 Select the size of the output disk, where the size can be specified
431 using common names such as "32G" (32 gigabytes) etc.
432 Virt-builder will resize filesystems inside the disk image
434 automatically.
435 If the size is not specified, then one of two things happens. If
437 the output is a file, then the size is the same as the template.
438 If the output is a device, partition, etc then the size of that
439 device is used.
440 To specify size in bytes, the number must be followed by the
442 lowercase letter b, eg: "--size 10737418240b".
443 --smp N
445 Enable N ≥ 2 virtual CPUs for --run scripts to use.
446 --source URL
448 Set the source URL to look for indexes.
449 You can give this option multiple times to specify multiple
451 sources.
452 See also "SOURCES OF TEMPLATES" below.
454 Note that you should not point --source to sources that you don’t
456 trust (unless the source is signed by someone you do trust). See
457 also the --no-network option.
458 --no-warn-if-partition
460 Do not emit a warning if the output device is a partition. This
461 warning avoids a common user error when writing to a USB key or
462 external drive, when you should normally write to the whole device
463 (--output /dev/sdX), not to a partition on the device
464 (--output /dev/sdX1). Use this option to suppress this warning.
465 -v
467 --verbose
468 Enable debug messages and/or produce verbose output.
469 When reporting bugs, use this option and attach the complete output
471 to your bug report.
472 -V
474 --version
475 Display version number and exit.
476 --wrap
478 Wrap error, warning, and informative messages. This is the default
479 when the output is a tty. If the output of the program is
480 redirected to a file, wrapping is disabled unless you use this
481 option.
482 -x Enable tracing of libguestfs API calls.
484 Customization options
486 --append-line FILE:LINE
487 Append a single line of text to the "FILE". If the file does not
488 already end with a newline, then one is added before the appended
489 line. Also a newline is added to the end of the "LINE" string
490 automatically.
491 For example (assuming ordinary shell quoting) this command:
493 --append-line '/etc/hosts:10.0.0.1 foo'
495 will add either "10.0.0.1 foo⏎" or "⏎10.0.0.1 foo⏎" to the file,
497 the latter only if the existing file does not already end with a
498 newline.
499 "⏎" represents a newline character, which is guessed by looking at
501 the existing content of the file, so this command does the right
502 thing for files using Unix or Windows line endings. It also works
503 for empty or non-existent files.
504 To insert several lines, use the same option several times:
506 --append-line '/etc/hosts:10.0.0.1 foo'
508 --append-line '/etc/hosts:10.0.0.2 bar'
509 To insert a blank line before the appended line, do:
511 --append-line '/etc/hosts:'
513 --append-line '/etc/hosts:10.0.0.1 foo'
514 --chmod PERMISSIONS:FILE
516 Change the permissions of "FILE" to "PERMISSIONS".
517 Note: "PERMISSIONS" by default would be decimal, unless you prefix
519 it with 0 to get octal, ie. use 0700 not 700.
520 --commands-from-file FILENAME
522 Read the customize commands from a file, one (and its arguments)
523 each line.
524 Each line contains a single customization command and its
526 arguments, for example:
527 delete /some/file
529 install some-package
530 password some-user:password:its-new-password
531 Empty lines are ignored, and lines starting with "#" are comments
533 and are ignored as well. Furthermore, arguments can be spread
534 across multiple lines, by adding a "\" (continuation character) at
535 the of a line, for example
536 edit /some/file:\
538 s/^OPT=.*/OPT=ok/
539 The commands are handled in the same order as they are in the file,
541 as if they were specified as --delete /some/file on the command
542 line.
543 --copy SOURCE:DEST
545 Copy files or directories recursively inside the guest.
546 Wildcards cannot be used.
548 --copy-in LOCALPATH:REMOTEDIR
550 Copy local files or directories recursively into the disk image,
551 placing them in the directory "REMOTEDIR" (which must exist).
552 Wildcards cannot be used.
554 --delete PATH
556 Delete a file from the guest. Or delete a directory (and all its
557 contents, recursively).
558 You can use shell glob characters in the specified path. Be
560 careful to escape glob characters from the host shell, if that is
561 required. For example:
562 virt-customize --delete '/var/log/*.log'.
564 See also: --upload, --scrub.
566 --edit FILE:EXPR
568 Edit "FILE" using the Perl expression "EXPR".
569 Be careful to properly quote the expression to prevent it from
571 being altered by the shell.
572 Note that this option is only available when Perl 5 is installed.
574 See "NON-INTERACTIVE EDITING" in virt-edit(1).
576 --firstboot SCRIPT
578 Install "SCRIPT" inside the guest, so that when the guest first
579 boots up, the script runs (as root, late in the boot process).
580 The script is automatically chmod +x after installation in the
582 guest.
583 The alternative version --firstboot-command is the same, but it
585 conveniently wraps the command up in a single line script for you.
586 You can have multiple --firstboot options. They run in the same
588 order that they appear on the command line.
589 Please take a look at "FIRST BOOT SCRIPTS" for more information and
591 caveats about the first boot scripts.
592 See also --run.
594 --firstboot-command 'CMD+ARGS'
596 Run command (and arguments) inside the guest when the guest first
597 boots up (as root, late in the boot process).
598 You can have multiple --firstboot options. They run in the same
600 order that they appear on the command line.
601 Please take a look at "FIRST BOOT SCRIPTS" for more information and
603 caveats about the first boot scripts.
604 See also --run.
606 --firstboot-install PKG,PKG..
608 Install the named packages (a comma-separated list). These are
609 installed when the guest first boots using the guest’s package
610 manager (eg. apt, yum, etc.) and the guest’s network connection.
611 For an overview on the different ways to install packages, see
613 "INSTALLING PACKAGES".
614 --hostname HOSTNAME
616 Set the hostname of the guest to "HOSTNAME". You can use a dotted
617 hostname.domainname (FQDN) if you want.
618 --install PKG,PKG..
620 Install the named packages (a comma-separated list). These are
621 installed during the image build using the guest’s package manager
622 (eg. apt, yum, etc.) and the host’s network connection.
623 For an overview on the different ways to install packages, see
625 "INSTALLING PACKAGES".
626 See also --update, --uninstall.
628 --link TARGET:LINK[:LINK..]
630 Create symbolic link(s) in the guest, starting at "LINK" and
631 pointing at "TARGET".
632 --mkdir DIR
634 Create a directory in the guest.
635 This uses "mkdir -p" so any intermediate directories are created,
637 and it also works if the directory already exists.
638 --move SOURCE:DEST
640 Move files or directories inside the guest.
641 Wildcards cannot be used.
643 --no-logfile
645 Scrub "builder.log" (log file from build commands) from the image
646 after building is complete. If you don't want to reveal precisely
647 how the image was built, use this option.
648 See also: "LOG FILE".
650 --password USER:SELECTOR
652 Set the password for "USER". (Note this option does not create the
653 user account).
654 See "USERS AND PASSWORDS" for the format of the "SELECTOR" field,
656 and also how to set up user accounts.
657 --password-crypto md5|sha256|sha512
659 When the virt tools change or set a password in the guest, this
660 option sets the password encryption of that password to "md5",
661 "sha256" or "sha512".
662 "sha256" and "sha512" require glibc ≥ 2.7 (check crypt(3) inside
664 the guest).
665 "md5" will work with relatively old Linux guests (eg. RHEL 3), but
667 is not secure against modern attacks.
668 The default is "sha512" unless libguestfs detects an old guest that
670 didn't have support for SHA-512, in which case it will use "md5".
671 You can override libguestfs by specifying this option.
672 Note this does not change the default password encryption used by
674 the guest when you create new user accounts inside the guest. If
675 you want to do that, then you should use the --edit option to
676 modify "/etc/sysconfig/authconfig" (Fedora, RHEL) or
677 "/etc/pam.d/common-password" (Debian, Ubuntu).
678 --root-password SELECTOR
680 Set the root password.
681 See "USERS AND PASSWORDS" for the format of the "SELECTOR" field,
683 and also how to set up user accounts.
684 Note: In virt-builder, if you don't set --root-password then the
686 guest is given a random root password.
687 --run SCRIPT
689 Run the shell script (or any program) called "SCRIPT" on the disk
690 image. The script runs virtualized inside a small appliance,
691 chrooted into the guest filesystem.
692 The script is automatically chmod +x.
694 If libguestfs supports it then a limited network connection is
696 available but it only allows outgoing network connections. You can
697 also attach data disks (eg. ISO files) as another way to provide
698 data (eg. software packages) to the script without needing a
699 network connection (--attach). You can also upload data files
700 (--upload).
701 You can have multiple --run options. They run in the same order
703 that they appear on the command line.
704 See also: --firstboot, --attach, --upload.
706 --run-command 'CMD+ARGS'
708 Run the command and arguments on the disk image. The command runs
709 virtualized inside a small appliance, chrooted into the guest
710 filesystem.
711 If libguestfs supports it then a limited network connection is
713 available but it only allows outgoing network connections. You can
714 also attach data disks (eg. ISO files) as another way to provide
715 data (eg. software packages) to the script without needing a
716 network connection (--attach). You can also upload data files
717 (--upload).
718 You can have multiple --run-command options. They run in the same
720 order that they appear on the command line.
721 See also: --firstboot, --attach, --upload.
723 --scrub FILE
725 Scrub a file from the guest. This is like --delete except that:
726 • It scrubs the data so a guest could not recover it.
728 • It cannot delete directories, only regular files.
730 --selinux-relabel
732 Relabel files in the guest so that they have the correct SELinux
733 label.
734 This will attempt to relabel files immediately, but if the
736 operation fails this will instead touch /.autorelabel on the image
737 to schedule a relabel operation for the next time the image boots.
738 You should only use this option for guests which support SELinux.
740 --sm-attach SELECTOR
742 Attach to a pool using "subscription-manager".
743 See "SUBSCRIPTION-MANAGER" for the format of the "SELECTOR" field.
745 --sm-credentials SELECTOR
747 Set the credentials for "subscription-manager".
748 See "SUBSCRIPTION-MANAGER" for the format of the "SELECTOR" field.
750 --sm-register
752 Register the guest using "subscription-manager".
753 This requires credentials being set using --sm-credentials.
755 --sm-remove
757 Remove all the subscriptions from the guest using
758 "subscription-manager".
759 --sm-unregister
761 Unregister the guest using "subscription-manager".
762 --ssh-inject USER[:SELECTOR]
764 Inject an ssh key so the given "USER" will be able to log in over
765 ssh without supplying a password. The "USER" must exist already in
766 the guest.
767 See "SSH KEYS" for the format of the "SELECTOR" field.
769 You can have multiple --ssh-inject options, for different users and
771 also for more keys for each user.
772 --timezone TIMEZONE
774 Set the default timezone of the guest to "TIMEZONE". Use a
775 location string like "Europe/London"
776 --touch FILE
778 This command performs a touch(1)-like operation on "FILE".
779 --truncate FILE
781 This command truncates "FILE" to a zero-length file. The file must
782 exist already.
783 --truncate-recursive PATH
785 This command recursively truncates all files under "PATH" to zero-
786 length.
787 --uninstall PKG,PKG..
789 Uninstall the named packages (a comma-separated list). These are
790 removed during the image build using the guest’s package manager
791 (eg. apt, yum, etc.). Dependent packages may also need to be
792 uninstalled to satisfy the request.
793 See also --install, --update.
795 --update
797 Do the equivalent of "yum update", "apt-get upgrade", or whatever
798 command is required to update the packages already installed in the
799 template to their latest versions.
800 See also --install, --uninstall.
802 --upload FILE:DEST
804 Upload local file "FILE" to destination "DEST" in the disk image.
805 File owner and permissions from the original are preserved, so you
806 should set them to what you want them to be in the disk image.
807 "DEST" could be the final filename. This can be used to rename the
809 file on upload.
810 If "DEST" is a directory name (which must already exist in the
812 guest) then the file is uploaded into that directory, and it keeps
813 the same name as on the local filesystem.
814 See also: --mkdir, --delete, --scrub.
816 --write FILE:CONTENT
818 Write "CONTENT" to "FILE".
819
821 INSTALLING PACKAGES
822 There are several approaches to installing packages or applications in
823 the guest which have different trade-offs.
824 Installing packages at build time
826 If the guest OS you are installing is similar to the host OS (eg. both
828 are Linux), and if libguestfs supports network connections, then you
829 can use --install to install packages like this:
830 virt-builder fedora-27 --install inkscape
832 This uses the guest’s package manager and the host’s network
834 connection.
835 Updating packages at build time
837 To update the installed packages in the template at build time:
839 virt-builder fedora-27 --update
841 Most of the templates that ship with virt-builder come with a very
843 minimal selection of packages (known as a "JEOS" or "Just Enough
844 Operating System"), which are up to date at the time the template is
845 created, but could be out of date by the time you come to install an OS
846 from the template. This option updates those template packages.
847 Installing packages at first boot
849 Another option is to install the packages when the guest first boots:
851 virt-builder fedora-27 --firstboot-install inkscape
853 This uses the guest’s package manager and the guest’s network
855 connection.
856 The downsides are that it will take the guest a lot longer to boot
858 first time, and there’s nothing much you can do if package installation
859 fails (eg. if a network problem means the guest can't reach the package
860 repositories).
861 Installing packages at build time from a side repository
863 If the software you want to install is not available in the main
865 package repository of the guest, then you can add a side repository.
866 Usually this is presented as an ISO (CD disk image) file containing
867 extra packages.
868 You can create the disk image using either genisoimage(1) or
870 virt-make-fs(1). For genisoimage, use a command like this:
871 genisoimage -o extra-packages.iso -R -J -V EXTRA cdcontents/
873 Create a script that mounts the ISO and sets up the repository. For
875 dnf, create /tmp/install.sh containing:
876 mkdir /tmp/mount
878 mount LABEL=EXTRA /tmp/mount
879 cat <<'EOF' > /etc/yum.repos.d/extra.repo
881 [extra]
882 name=extra
883 baseurl=file:///tmp/mount
884 enabled=1
885 EOF
886 dnf -y install famousdatabase
888 For apt, create /tmp/install.sh containing:
890 mkdir /tmp/mount
892 mount LABEL=EXTRA /tmp/mount
893 apt-cdrom -d=/tmp/mount add
895 apt-get -y install famousdatabase
896 Use the --attach option to attach the CD / disk image and the --run
898 option to run the script:
899 virt-builder fedora-27 \
901 --attach extra-packages.iso \
902 --run /tmp/install.sh
903 USERS AND PASSWORDS
905 The --root-password option is used to change the root password
906 (otherwise a random password is used). This option takes a password
907 "SELECTOR" in one of the following formats:
908 --root-password file:FILENAME
910 Read the root password from "FILENAME". The whole first line of
911 this file is the replacement password. Any other lines are
912 ignored. You should create the file with mode 0600 to ensure no
913 one else can read it.
914 --root-password password:PASSWORD
916 Set the root password to the literal string "PASSWORD".
917 Note: this is not secure since any user on the same machine can see
919 the cleartext password using ps(1).
920 --root-password random
922 Choose a random password, which is printed on stdout. The password
923 has approximately 120 bits of randomness.
924 This is the default.
926 --root-password disabled
928 The root account password is disabled. This is like putting "*" in
929 the password field.
930 --root-password locked:file:FILENAME
932 --root-password locked:password:PASSWORD
933 --root-password locked:random
934 The root account is locked, but a password is placed on the
935 account. If first unlocked (using "passwd -u") then logins will
936 use the given password.
937 --root-password locked
939 --root-password locked:disabled
940 The root account is locked and password is disabled.
941 Creating user accounts
943 To create user accounts, use the useradd(8) command with
945 --firstboot-command like this:
946 virt-builder --firstboot-command \
948 'useradd -m -p "" rjones ; chage -d 0 rjones'
949 The above command will create an "rjones" account with no password, and
951 force the user to set a password when they first log in. There are
952 other ways to manage passwords, see useradd(8) for details.
953 KEYBOARD LAYOUT
955 Because there are so many different ways to set the keyboard layout in
956 Linux distributions, virt-builder does not yet attempt to have a simple
957 command line option. This section describes how to set the keyboard
958 for some common Linux distributions.
959 Keyboard layout with systemd
961 For distros that use systemd "localectl", use a command like this:
963 virt-builder fedora-27 \
965 --firstboot-command 'localectl set-keymap uk'
966 See localectl(1) and
968 https://www.happyassassin.net/2013/11/23/keyboard-layouts-in-fedora-20-and-previously/
969 for more details.
970 Keyboard layout using /etc/sysconfig/keyboard
972 For RHEL ≤ 6, Fedora ≤ 18 and similar, upload or modify the keyboard
974 configuration file using the --upload, --write or --edit options. For
975 example:
976 virt-builder centos-6 \
978 --edit '/etc/sysconfig/keyboard: s/^KEYTABLE=.*/KEYTABLE="uk"/'
979 The format of this file can be found documented in many places online.
981 Keyboard layout with Debian-derived distros
983 For Debian-derived distros using /etc/default/keyboard, upload or
985 modify the keyboard file using the --upload, --write or --edit options.
986 For example:
987 virt-builder debian-8 \
989 --edit '/etc/default/keyboard: s/^XKBLAYOUT=.*/XKBLAYOUT="gb"/'
990 See https://wiki.debian.org/Keyboard.
992 LANGUAGE
994 Most Linux distributions support multiple locale settings so that you
995 can have guest messages printed in another language such as Russian.
996 However there is no single setting which controls this, since extra
998 packages may need to be installed to support console and X fonts, and
999 keyboard input methods. The packages required, and their configuration
1000 is highly distro-specific, and it is outside the scope of virt-builder
1001 to do this.
1002 This section contains examples for some common Linux distributions.
1004 Setting Japanese in Fedora 25
1006 virt-builder fedora-27 \
1008 --size 20G \
1009 --update \
1010 --install @japanese-support \
1011 --install @xfce \
1012 --install xorg-x11-server-Xorg,xorg-x11-drivers,rsyslog \
1013 --link /usr/lib/systemd/system/graphical.target:/etc/systemd/system/default.target \
1014 --firstboot-command 'localectl set-locale LANG=ja_JP.utf8' \
1015 --firstboot-command 'localectl set-keymap jp' \
1016 --firstboot-command 'systemctl isolate graphical.target'
1017 Setting Japanese in Debian 8 (Jessie)
1019 Note that although this enables Japanese in the text console too, it is
1021 unlikely that you will see properly rendered Japanese there. However
1022 Japanese is properly rendered in X applications and terminals.
1023 pkgs=locales,xfce4,\
1025 ibus,ibus-anthy,\
1026 fonts-ipafont-gothic,fonts-ipafont-mincho,\
1027 fonts-takao-mincho,\
1028 xfonts-intl-japanese,xfonts-intl-japanese-big,\
1029 iceweasel-l10n-ja,manpages-ja
1030 virt-builder debian-8 \
1032 --size 20G \
1033 --install $pkgs \
1034 --edit '/etc/locale.gen: s,^#\s*ja,ja,' \
1035 --write '/etc/default/locale:LANG="ja_JP.UTF-8"' \
1036 --run-command "locale-gen"
1037 LOG FILE
1039 Scripts and package installation that runs at build time (--run,
1040 --run-command, --install, --update, but not firstboot) is logged in one
1041 of the following locations:
1042 /tmp/builder.log
1044 On Linux, BSD, and other non-Windows guests.
1045 C:\Temp\builder.log
1047 On Windows, DOS guests.
1048 /builder.log
1050 If /tmp or C:\Temp is missing.
1051 If you don’t want the log file to appear in the final image, then use
1053 the --no-logfile command line option.
1054 SSH KEYS
1056 The --ssh-inject option is used to inject ssh keys for users in the
1057 guest, so they can login without supplying a password.
1058 The "SELECTOR" part of the option value is optional; in this case,
1060 --ssh-inject "USER" means that we look in the current user’s ~/.ssh
1061 directory to find the default public ID file. That key is uploaded.
1062 "default public ID" is the default_ID_file file described in
1063 ssh-copy-id(1).
1064 If specified, the "SELECTOR" can be in one of the following formats:
1066 --ssh-inject USER:file:FILENAME
1068 Read the ssh key from FILENAME. FILENAME is usually a .pub file.
1069 --ssh-inject USER:string:KEY_STRING
1071 Use the specified "KEY_STRING". "KEY_STRING" is usually a public
1072 string like ssh-rsa AAAA.... user@localhost.
1073 In any case, the ~USER/.ssh directory and the
1075 ~USER/.ssh/authorized_keys file will be created if not existing
1076 already.
1077 FIRST BOOT SCRIPTS
1079 The --firstboot and --firstboot-command options allow you to execute
1080 commands at the first boot of the guest. To do so, an init script for
1081 the guest init system is installed, which takes care of running all the
1082 added scripts and commands.
1083 Supported operating systems are:
1085 Linux
1087 Init systems supported are: systemd, System-V init (known also as
1088 sysvinit), and Upstart (using the System-V scripts).
1089 Note that usually init scripts run as root, but with a more limited
1091 environment than what could be available from a normal shell: for
1092 example, $HOME may be unset or empty.
1093 The output of the first boot scripts is available in the guest as
1095 ~root/virt-sysprep-firstboot.log.
1096 Windows
1098 rhsrvany.exe, available from sources at
1099 https://github.com/rwmjones/rhsrvany, or pvvxsvc.exe, available
1100 with SUSE VMDP is installed to run the first boot scripts. It is
1101 required, and the setup of first boot scripts will fail if it is
1102 not present.
1103 rhsrvany.exe or pvvxsvc.exe is copied from the location pointed to
1105 by the "VIRT_TOOLS_DATA_DIR" environment variable; if not set, a
1106 compiled-in default will be used (something like
1107 /usr/share/virt-tools).
1108 The output of the first boot scripts is available in the guest as
1110 C:\Program Files\Guestfs\Firstboot\log.txt.
1111 SUBSCRIPTION-MANAGER
1113 It is possible to automate the registration and attaching of the system
1114 using "subscription-manager". This is typical on Red Hat Enterprise
1115 Linux guests. There are few options which ease this process, avoid
1116 executing commands manually and exposing passwords on command line.
1117 --sm-register starts the registration process, and requires
1119 --sm-credentials to be specified; the format of the "SELECTOR" of
1120 --sm-credentials is one of the following formats:
1121 --sm-credentials USER:file:FILENAME
1123 Read the password for the specified "USER" from FILENAME.
1124 --sm-credentials USER:password:PASSWORD
1126 Use the literal string "PASSWORD" for the specified "USER".
1127 --sm-attach attaches the system to subscriptions; the format of its
1129 "SELECTOR" is one of the following:
1130 --sm-attach auto
1132 "subscription-manager" attaches to the best-fitting subscriptions
1133 for the system.
1134 --sm-attach file:FILENAME
1136 Read the pool ID from FILENAME.
1137 --sm-attach pool:POOL
1139 Use the literal string "POOL" as pool ID.
1140 --sm-remove removes all the subscriptions from the guest, while
1142 --sm-unregister completely unregister the system.
1143 INSTALLATION PROCESS
1145 When you invoke virt-builder, installation proceeds as follows:
1146 • The template image is downloaded.
1148 If the template image is present in the cache, the cached version
1150 is used instead. (See "CACHING").
1151 • The template signature is checked.
1153 • The template is uncompressed to a tmp file.
1155 • The template image is resized into the destination, using
1157 virt-resize(1).
1158 • Extra disks are attached (--attach).
1160 • A new random seed is generated for the guest.
1162 • Guest customization is performed, in the order specified on the
1164 command line.
1165 • SELinux relabelling is done (--selinux-relabel).
1167 IMPORTING THE DISK IMAGE
1169 Importing into libvirt
1170 Import the disk image into libvirt using virt-install(1) --import
1172 option.
1173 virt-install --import \
1175 --name guest --ram 2048 \
1176 --disk path=disk.img,format=raw --os-variant fedora27
1177 Notes:
1179 1. You must specify the correct format. The format is "raw" unless
1181 you used virt-builder’s --format option.
1182 2. --os-variant is highly recommended, because it will present optimum
1184 devices to enable the guest to run most efficiently. To get a list
1185 of all variants, do:
1186 osinfo-query os
1188 The above tool is provided by libosinfo package.
1190 3. You can run virt-install as root or non-root. Each works slightly
1192 differently because libvirt manages a different set of virtual
1193 machines for each user. In particular virt-manager normally shows
1194 the root-owned VMs, whereas Boxes shows the user-owned VMs, and
1195 other tools probably work differently as well.
1196 Importing into OpenStack
1198 Import the image into Glance (the OpenStack image store) by doing:
1200 glance image-create --name fedora-27-image --file fedora-27.img \
1202 --disk-format raw --container-format bare \
1203 --is-public True
1204 The --file parameter is the virt-builder-generated disk image. It
1206 should match virt-builder’s --output option. The --disk-format
1207 parameter should match virt-builder’s --format option (or "raw" if you
1208 didn't use that option). The --container-format should always be
1209 "bare" since virt-builder doesn't put images into containers.
1210 You can use the "glance image-show fedora-27-image" command to display
1212 the properties of the image.
1213 To boot up an instance of your image on a Nova compute node, do:
1215 nova boot fedora-27-server --image fedora-27-image \
1217 --flavor m1.medium
1218 Use "nova flavor-list" to list possible machine flavors. Use
1220 "nova list" to list running instances.
1221 Booting directly using qemu or KVM
1223 The qemu command line is not very stable or easy to use, hence libvirt
1225 should be used if possible. However a command line similar to the
1226 following could be used to boot the virtual machine:
1227 qemu-system-x86_64 \
1229 -machine accel=kvm:tcg \
1230 -cpu host \
1231 -m 2048 \
1232 -drive file=disk.img,format=raw,if=virtio
1233 As with libvirt, it is very important that the correct format is
1235 chosen. It will be "raw" unless the --format option was used.
1236 CONFIGURATION MANAGEMENT
1238 Puppet
1239 To enable the Puppet agent in a guest, install the package, point the
1241 configuration at your Puppetmaster, and ensure the agent runs at boot.
1242 A typical virt-builder command would be:
1244 virt-builder fedora-27 \
1246 --hostname client.example.com \
1247 --update \
1248 --install puppet \
1249 --append-line '/etc/puppet/puppet.conf:[agent]' \
1250 --append-line '/etc/puppet/puppet.conf:server = puppetmaster.example.com/' \
1251 --run-command 'systemctl enable puppet' \
1252 --selinux-relabel
1253 The precise instructions vary according to the Linux distro. For
1255 further information see:
1256 https://docs.puppet.com/puppet/latest/install_pre.html
1257 DEBUGGING BUILDS
1259 If virt-builder itself fails, then enable debugging (-v) and report a
1260 bug (see "BUGS" below).
1261 If virt-builder fails because some script or package it is installing
1263 fails, try using --no-delete-on-failure to preserve the output file,
1264 and continue reading this section.
1265 If virt-builder is successful but the image doesn't work, here are some
1267 things to try:
1268 Use virt-rescue
1270 Run virt-rescue(1) on the disk image:
1271 virt-rescue -a disk.img
1273 This gives you a rescue shell. You can mount the filesystems from
1275 the disk image on /sysroot and examine them using ordinary Linux
1276 commands. You can also chroot into the guest to reinstall the
1277 bootloader. The virt-rescue man page has a lot more information
1278 and examples.
1279 Use guestfish
1281 Run guestfish(1) on the disk image:
1282 guestfish -a disk.img -i
1284 Use guestfish commands like "ll /directory" and "cat /file" to
1286 examine directories and files.
1287 Use guestmount
1289 Mount the disk image safely on the host using FUSE and
1290 guestmount(1):
1291 mkdir /tmp/mp
1293 guestmount -a disk.img -i /tmp/mp
1294 cd /tmp/mp
1295 To unmount the disk image do:
1297 fusermount -u /tmp/mp
1299 Add a serial console
1301 If the guest hangs during boot, it can be helpful to add a serial
1302 console to the guest, and direct kernel messages to the serial
1303 console. Adding the serial console will involve looking at the
1304 documentation for your hypervisor. To direct kernel messages to
1305 the serial console, add the following on the kernel command line:
1306 console=tty0 console=ttyS0,115200
1308 SOURCES OF TEMPLATES
1310 virt-builder reads the available sources from configuration files, with
1311 the .conf extension and located in the following paths:
1312 • $XDG_CONFIG_HOME/virt-builder/repos.d/ ($XDG_CONFIG_HOME is
1314 $HOME/.config if not set).
1315 • $VIRT_BUILDER_DIRS/virt-builder/repos.d/ (where $VIRT_BUILDER_DIRS
1317 means any of the directories in that environment variable, or just
1318 /etc if not set).
1319 Each .conf file in those paths has a simple text format like the
1321 following:
1322 [libguestfs.org]
1324 uri=http://libguestfs.org/download/builder/index.asc
1325 gpgkey=file:///etc/xdg/virt-builder/repos.d/libguestfs.gpg
1326 The part in square brackets is the repository identifier, which is used
1328 as unique identifier.
1329 The following fields can appear:
1331 "uri=URI"
1333 The URI of the index file which this repository refers to.
1334 This field is required.
1336 "gpgkey=URI"
1338 This optional field represents the URI (although only file:// URIs
1339 are accepted) of the key used to sign the index file. If not
1340 present, the index file referred by uri=.. is not signed.
1341 "proxy=MODE"
1343 This optional field specifies the proxy mode, to be used when
1344 downloading the index file of this repository. The possible values
1345 are:
1346 no, off
1348 No proxy is being used at all, even overriding the system
1349 configuration.
1350 system
1352 The proxy used is the system one.
1353 anything else
1355 Specifies the actual proxy configuration to be used, overriding
1356 the system configuration.
1357 If not present, the assumed value is to respect the proxy settings
1359 of the system (i.e. as if system would be specified).
1360 "format=FORMAT"
1362 This optional field specifies the format of the repository. The
1363 possible values are:
1364 native
1366 The native format of the "virt-builder" repository. See also
1367 "Creating and signing the index file" below.
1368 simplestreams
1370 The URI represents the root of a Simple Streams v1.0 tree of
1371 metadata.
1372 For more information about Simple Streams, see also
1374 https://launchpad.net/simplestreams.
1375 If not present, the assumed value is "native".
1377 For serious virt-builder use, you may want to create your own
1379 repository of templates.
1380 Libguestfs.org repository
1382 Out of the box, virt-builder downloads the file
1384 http://libguestfs.org/download/builder/index.asc which is an index of
1385 available templates plus some information about each one, wrapped up in
1386 a digital signature. The command "virt-builder --list" lists out the
1387 information in this index file.
1388 The templates hosted on libguestfs.org were created using shell
1390 scripts, kickstart files and preseed files which can be found in the
1391 libguestfs source tree, in "builder/templates".
1392 Setting up the repository
1394 You can set up your own site containing an index file and some
1396 templates, and then point virt-builder at the site by creating a .conf
1397 file pointing to it.
1398 Note that if your index is signed, you will need to properly fill
1400 gpgkey=.. in your .conf file, making sure to deploy also the GPG key
1401 file.
1402 virt-builder --source https://example.com/builder/index.asc \
1404 --fingerprint 'AAAA BBBB ...' \
1405 --list
1406 You can host this on any web or FTP server, or a local or network
1408 filesystem.
1409 Setting up a GPG key
1411 If you don’t have a GnuPG key, you will need to set one up. (Strictly
1413 speaking this is optional, but if your index and template files are not
1414 signed then virt-builder users will have to use the
1415 --no-check-signature flag every time they use virt-builder.)
1416 To create a key, see the GPG manual
1418 http://www.gnupg.org/gph/en/manual.html.
1419 Export your GPG public key:
1421 gpg --export -a "you@example.com" > pubkey
1423 Create the templates
1425 There are many ways to create the templates. For example you could
1427 clone existing guests (see virt-sysprep(1)), or you could install a
1428 guest by hand (virt-install(1)). To see how the templates were created
1429 for virt-builder, look at the scripts in "builder/templates"
1430 Virt-builder supports any image format (e.g. raw, qcow2, etc) as
1432 template, both as-is, and compressed as XZ. This way, existing images
1433 (e.g. cleaned using virt-sysprep(1)) can be used as templates.
1434 For best results when compressing the templates, use the following xz
1436 options (see nbdkit-xz-plugin(1) for further explanation):
1437 xz --best --block-size=16777216 disk
1439 Creating and signing the index file
1441 The index file has a simple text format (shown here without the digital
1443 signature):
1444 [fedora-18]
1446 name=Fedora® 18
1447 osinfo=fedora18
1448 arch=x86_64
1449 file=fedora-18.xz
1450 checksum[sha512]=...
1451 format=raw
1452 size=6442450944
1453 compressed_size=148947524
1454 expand=/dev/sda3
1455 [fedora-19]
1457 name=Fedora® 19
1458 osinfo=fedora19
1459 arch=x86_64
1460 file=fedora-19.xz
1461 checksum[sha512]=...
1462 revision=3
1463 format=raw
1464 size=4294967296
1465 compressed_size=172190964
1466 expand=/dev/sda3
1467 The part in square brackets is the "os-version", which is the same
1469 string that is used on the virt-builder command line to build that OS.
1470 The index file creation and signature can be eased with the
1472 virt-builder-repository(1) tool.
1473 After preparing the "index" file in the correct format, clearsign it
1475 using the following command:
1476 gpg --clearsign --armor index
1478 This will create the final file called index.asc which can be uploaded
1480 to the server (and is the uri=.. URL). As noted above, signing the
1481 index file is optional, but recommended.
1482 The following fields can appear:
1484 "name=NAME"
1486 The user-friendly name of this template. This is displayed in the
1487 --list output but is otherwise not significant.
1488 "osinfo=ID"
1490 This optional field maps the operating system to the associated
1491 libosinfo ID. Virt-builder does not use it (yet).
1492 "arch=ARCH"
1494 The architecture of the operating system installed within the
1495 template. This field is required.
1496 "file=PATH"
1498 The path (relative to the index) of the xz-compressed template.
1499 Note that absolute paths or URIs are not permitted here. This is
1501 because virt-builder has a "same origin" policy for templates so
1502 they cannot come from other servers.
1503 "sig=PATH"
1505 This option is deprecated. Use the checksum field instead.
1506 The path (relative to the index) of the GPG detached signature of
1508 the xz file.
1509 Note that absolute paths or URIs are not permitted here. This is
1511 because virt-builder has a "same origin" policy for templates so
1512 they cannot come from other servers.
1513 The file can be created as follows:
1515 gpg --detach-sign --armor -o disk.xz.sig disk.xz
1517 "checksum[sha512]=7b882fe9b82eb0fef..."
1519 The SHA-512 checksum of the file specified in file=.. is checked
1520 after it is downloaded. To work out the signature, do:
1521 sha512sum disk.xz
1523 Note if you use this, you don’t need to sign the file, ie. don’t
1525 use "sig". This option overrides "sig".
1526 "checksum=7b882fe9b82eb0fef..."
1528 "checksum" is an alias for "checksum[sha512]".
1529 If you need to interoperate with virt-builder = 1.24.0 then you
1531 have to use "checksum" because that version would give a parse
1532 error with square brackets and numbers in the key of a field. This
1533 is fixed in virt-builder ≥ 1.24.1.
1534 "revision=N"
1536 The revision is an integer which is used to control the template
1537 cache. Increasing the revision number causes clients to download
1538 the template again even if they have a copy in the cache.
1539 The revision number is optional. If omitted it defaults to 1.
1541 "format=raw"
1543 "format=qcow2"
1544 Specify the format of the disk image; in case it is compressed,
1545 that is the format before the compression. If not given, the
1546 format is autodetected, but generally it is better to be explicit
1547 about the intended format.
1548 Note this is the source format, which is different from the
1550 --format option (requested output format). Virt-builder does on-
1551 the-fly conversion from the source format to the requested output
1552 format.
1553 "size=NNN"
1555 The virtual size of the image in bytes. This is the size of the
1556 image when uncompressed. If using a non-raw format such as qcow2
1557 then it means the virtual disk size, not the size of the qcow2
1558 file.
1559 This field is required.
1561 Virt-builder also uses this as the minimum size that users can
1563 request via the --size option, or as the default size if there is
1564 no --size option.
1565 "compressed_size=NNN"
1567 The actual size of the disk image in bytes, i.e. what was specified
1568 in file=... This is just used for information (when using "long",
1569 and "json" formats of --list).
1570 "expand=/dev/sdaX"
1572 When expanding the image to its final size, instruct virt-resize(1)
1573 to expand the named partition in the guest image to fill up all
1574 available space. This works like the virt-resize --expand option.
1575 You should usually put the device name of the guest’s root
1577 filesystem here.
1578 It’s a good idea to use this, but not required. If the field is
1580 omitted then virt-resize will create an extra partition at the end
1581 of the disk to cover the free space, which is much less user-
1582 friendly.
1583 "lvexpand=/dev/VolGroup/LogVol"
1585 When expanding the image to its final size, instruct virt-resize(1)
1586 to expand the named logical volume in the guest image to fill up
1587 all available space. This works like the virt-resize --lv-expand
1588 option.
1589 If the guest uses LVM2 you should usually put the LV of the guest’s
1591 root filesystem here. If the guest does not use LVM2 or its root
1592 filesystem is not on an LV, don't use this option.
1593 "notes=NOTES"
1595 Any notes that go with this image, especially notes describing what
1596 packages are in the image, how the image was prepared, and
1597 licensing information.
1598 This information is shown in the --notes and --list --long modes.
1600 You can use multi-line notes here by indenting each new line with
1602 at least one character of whitespace (even on blank lines):
1603 notes=This image was prepared using
1605 the following kickstart script:
1606 <-- one space at beginning of line
1607 part /boot --fstype ext3
1608 ...
1609 "hidden=true"
1611 Using the hidden flag prevents the template from being listed by
1612 the --list option (but it is still installable). This is used for
1613 test images.
1614 "aliases=ALIAS1 ALIAS2 ..."
1616 This optional field specifies a list of aliases, separated by
1617 spaces, for the image. For example, an alias could be used to
1618 always point to the latest version of a certain image, leaving the
1619 old versions available in the index instead of updating the same
1620 image (see the "revision" field).
1621 Running virt-builder against multiple sources
1623 It is possible to use multiple sources with virt-builder. The
1625 recommended way is to deploy .conf files pointing to the index files.
1626 Another way is to specify the sources using multiple --source and/or
1627 --fingerprint options:
1628 virt-builder \
1630 --source http://example.com/s1/index.asc \
1631 --source http://example.com/s2/index.asc
1632 You can provide N or 1 fingerprints. In the case where you provide N
1634 fingerprints, N = number of sources and there is a 1-1 correspondence
1635 between each source and each fingerprint:
1636 virt-builder \
1638 --source http://example.com/s1/index.asc --fingerprint '0123 ...' \
1639 --source http://example.com/s2/index.asc --fingerprint '9876 ...'
1640 In the case where you provide 1 fingerprint, the same fingerprint is
1642 used for all sources.
1643 You "must" provide at least 1 fingerprint.
1645 Licensing of templates
1647 You should be aware of the licensing of images that you distribute.
1649 For open source guests, provide a link to the source code in the
1650 "notes" field and comply with other requirements (eg. around
1651 trademarks).
1652 Formal specification of the index file
1654 The index file format has a formal specification defined by the flex
1656 scanner and bison parser used to parse the file. This can be found in
1657 the following files in the libguestfs source tree:
1658 builder/index-scan.l
1660 builder/index-parse.y
1661 A tool called virt-index-validate(1) is available to validate the index
1663 file to ensure it is correct.
1664 Note that the parser and tool can work on either the signed or unsigned
1666 index file (ie. index or index.asc).
1667 The index is always encoded in UTF-8.
1669 CACHING
1671 Caching templates
1672 Since the templates are usually very large, downloaded templates are
1674 cached in the user’s home directory.
1675 The location of the cache is $XDG_CACHE_HOME/virt-builder/ or
1677 $HOME/.cache/virt-builder.
1678 You can print out information about the cache directory, including
1680 which guests are currently cached, by doing:
1681 virt-builder --print-cache
1683 The cache can be deleted if you want to save space by doing:
1685 virt-builder --delete-cache
1687 You can download all (current) templates to the local cache by doing:
1689 virt-builder --cache-all-templates
1691 To disable the template cache, use --no-cache.
1693 Only templates are cached. The index and detached digital signatures
1695 are not cached.
1696 Caching packages
1698 Virt-builder uses curl(1) to download files and it also uses the
1700 current "http_proxy" (etc) settings when installing packages
1701 (--install, --update).
1702 You may therefore want to set those environment variables in order to
1704 maximize the amount of local caching that happens. See "ENVIRONMENT
1705 VARIABLES" and curl(1).
1706 Local mirrors
1708 To increase both speed and reliability of installing packages, you can
1710 set up a local mirror of the target distribution, and point the guest
1711 package manager at that.
1712 Using a local mirror with Fedora
1714 To install a Fedora guest using a local mirror:
1716 virt-builder fedora-27 \
1718 --edit '/etc/yum.repos.d/fedora.repo:
1719 s{.*baseurl=.*}{baseurl=http://example.com/mirror/};
1720 s{.*metalink=.*}{};
1721 ' \
1722 --edit '/etc/yum.repos.d/fedora-updates.repo:
1723 s{.*baseurl=.*}{baseurl=http://example.com/mirror-updates/};
1724 s{.*metalink=.*}{};
1725 ' \
1726 --run-command 'dnf -y update' \
1727 --install 'pkg1,pkg2,...'
1728 Using a local mirror with Debian
1730 Assuming that you are using "apt-proxy" to mirror the repository, you
1732 should create a new sources.list file to point to your proxy (see
1733 https://help.ubuntu.com/community/AptProxy) and then do:
1734 virt-builder debian-8 \
1736 --upload sources.list:/etc/apt/sources.list \
1737 --run-command 'apt-get -y update' \
1738 --install 'pkg1,pkg2,...'
1739 DIGITAL SIGNATURES
1741 Virt-builder uses GNU Privacy Guard (GnuPG or gpg) to verify that the
1742 index and templates have not been tampered with.
1743 The source points to an index file, which is optionally signed.
1745 Virt-builder downloads the index and checks that the signature is valid
1747 and the signer’s fingerprint matches the specified fingerprint (ie. the
1748 one specified in gpgkey=.. in the .conf, or with --fingerprint, in that
1749 order).
1750 For checking against the built-in public key/fingerprint, this requires
1752 importing the public key into the user’s local gpg keyring (that’s just
1753 the way that gpg works).
1754 When a template is downloaded, its signature is checked in the same
1756 way.
1757 Although the signatures are optional, if you don’t have them then virt-
1759 builder users will have to use --no-check-signature on the command
1760 line. This prevents an attacker from replacing the signed index file
1761 with an unsigned index file and having virt-builder silently work
1762 without checking the signature. In any case it is highly recommended
1763 that you always create signed index and templates.
1764 ARCHITECTURE
1766 Virt-builder can build a guest for any architecture no matter what the
1767 host architecture is. For example an x86-64 guest on an ARM host.
1768 However certain options may not work, specifically options that require
1770 running commands in the guest during the build process: --install,
1771 --update, --run, --run-command. You may need to replace these with
1772 their firstboot-equivalents.
1773 An x86-64 host building 32 bit i686 guests should work without any
1775 special steps.
1776 SECURITY
1778 Virt-builder does not need to run as root (in fact, should not be run
1779 as root), and doesn't use setuid, "sudo" or any similar mechanism.
1780 --install, --update, --run and --run-command are implemented using an
1782 appliance (a small virtual machine) so these commands do not run on the
1783 host. If you are using the libguestfs libvirt backend and have SELinux
1784 enabled then the virtual machine is additionally encapsulated in an
1785 SELinux container (sVirt).
1786 However these options will have access to the host’s network and since
1788 the template may contain untrusted code, the code might try to access
1789 host network resources which it should not. You can use --no-network
1790 to prevent this.
1791 Firstboot commands run in the context of the guest when it is booted,
1793 and so the security of your hypervisor / cloud should be considered.
1794 Virt-builder injects a random seed into every guest which it builds.
1796 This helps to ensure that TCP sequence numbers, UUIDs, ssh host keys
1797 etc are truly random when the guest boots.
1798 You should check digital signatures and not ignore any signing errors.
1800 CLONES
1802 If you wish to create many new guests of the same type, it is tempting
1803 to run virt-builder once and then copy the output file. You should not
1804 do this. You should run virt-builder once for each new guest you need.
1805 The reason is that each clone needs to have (at least) a separate
1807 random seed, and possibly other unique features (such as filesystem
1808 UUIDs) in future versions of virt-builder.
1809 Another thing you should not do is to boot the guest, then clone the
1811 booted disk image. The reason is that some guests create unique
1812 machine IDs, SSH host keys and so on at first boot, and you would not
1813 want clones to have duplicate identities.
1814 See also: virt-sysprep(1).
1816 PERFORMANCE
1818 The most important aspect of getting good performance is caching.
1819 Templates gets downloaded into the cache the first time they are used,
1820 or if you use the --cache-all-templates option. See "CACHING" above
1821 for further information.
1822 Packages required for the --install and --update options are downloaded
1824 using the host network connection. Setting the "http_proxy",
1825 "https_proxy" and "ftp_proxy" environment variables to point to a local
1826 web cache may ensure they only need to be downloaded once. You can
1827 also try using a local package repository, although this can be complex
1828 to set up and varies according to which Linux distro you are trying to
1829 install.
1830 Using --no-sync
1832 Use --no-sync. However read the caveats in the "OPTIONS" section
1834 above, since this can cause disk corruption if not used correctly.
1835 Skipping virt-resize
1837 Virt-builder can skip the virt-resize step under certain conditions.
1839 This makes virt-builder much faster. The conditions are:
1840 • the output must be a regular file (not a block device), and
1842 • the user did not use the --size option, and
1844 • the output format is the same as the template format (usually raw).
1846 pxzcat
1848 Virt-builder uses an internal implementation of pxzcat (parallel xzcat)
1850 if liblzma was found at build time. If liblzma was not found at build
1851 time, regular "xzcat" is used which is single-threaded.
1852 SELINUX
1854 Guests which use SELinux (such as Fedora and Red Hat Enterprise Linux)
1855 require that each file has a correct SELinux label.
1856 Virt-builder does not know how to give new files a label, so there are
1858 two possible strategies it can use to ensure correct labelling:
1859 Using --selinux-relabel
1861 This runs setfiles(8) just before finalizing the guest, which sets
1862 SELinux labels correctly in the disk image.
1863 This is the recommended method.
1865 --touch /.autorelabel
1867 Guest templates may already contain a file called /.autorelabel or
1868 you may touch it.
1869 For guests that use SELinux, this causes restorecon(8) to run at
1871 first boot. Guests will reboot themselves once the first time you
1872 use them, which is normal and harmless.
1873 Please note that if your guest uses SELinux, and you are doing
1875 operations on it which might create new files or change existing ones,
1876 you are recommended to use --selinux-relabel. This will help in making
1877 sure that files have the right SELinux labels.
1878
1880 The --machine-readable option can be used to make the output more
1881 machine friendly, which is useful when calling virt-builder from other
1882 programs, GUIs etc.
1883 Use the option on its own to query the capabilities of the virt-builder
1885 binary. Typical output looks like this:
1886 $ virt-builder --machine-readable
1888 virt-builder
1889 arch
1890 config-file
1891 customize
1892 json-list
1893 pxzcat
1894 A list of features is printed, one per line, and the program exits with
1896 status 0.
1897 It is possible to specify a format string for controlling the output;
1899 see "ADVANCED MACHINE READABLE OUTPUT" in guestfs(3).
1900
1902 For other environment variables which affect all libguestfs programs,
1903 see "ENVIRONMENT VARIABLES" in guestfs(3).
1904 "http_proxy"
1906 "https_proxy"
1907 "no_proxy"
1908 Set the proxy for downloads. These environment variables (and
1909 more) are actually interpreted by curl(1), not virt-builder.
1910 "HOME"
1912 Used to determine the location of the template cache, and the
1913 location of the user' sources. See "CACHING" and "SOURCES OF
1914 TEMPLATES".
1915 "VIRT_TOOLS_DATA_DIR"
1917 This can point to the directory containing data files used for
1918 Windows firstboot installation.
1919 Normally you do not need to set this. If not set, a compiled-in
1921 default will be used (something like /usr/share/virt-tools).
1922 This directory may contain the following files:
1924 rhsrvany.exe
1926 This is the RHSrvAny Windows binary, used to install a
1927 "firstboot" script in Windows guests. It is required if you
1928 intend to use the --firstboot or --firstboot-command options
1929 with Windows guests.
1930 See also: "https://github.com/rwmjones/rhsrvany"
1932 pvvxsvc.exe
1934 This is a Windows binary shipped with SUSE VMDP, used to
1935 install a "firstboot" script in Windows guests. It is required
1936 if you intend to use the --firstboot or --firstboot-command
1937 options with Windows guests.
1938 "XDG_CACHE_HOME"
1940 Used to determine the location of the template cache. See
1941 "CACHING".
1942 "XDG_CONFIG_HOME"
1944 Used to determine the location of the user' sources. See "SOURCES
1945 OF TEMPLATES".
1946 "VIRT_BUILDER_DIRS"
1948 Used to determine the location of the system sources. See "SOURCES
1949 OF TEMPLATES".
1950
1952 This program returns 0 if successful, or non-zero if there was an
1953 error.
1954
1956 guestfs(3), guestfish(1), guestmount(1), virt-builder-repository(1),
1957 virt-copy-out(1), virt-customize(1), virt-get-kernel(1),
1958 virt-install(1), virt-rescue(1), virt-resize(1), virt-sysprep(1),
1959 oz-install(1), gpg(1), gpg2(1), curl(1), virt-make-fs(1),
1960 genisoimage(1), http://libguestfs.org/.
1961
1963 Richard W.M. Jones http://people.redhat.com/~rjones/
1964
1966 Copyright (C) 2013 Red Hat Inc.
1967
1969 This program is free software; you can redistribute it and/or modify it
1970 under the terms of the GNU General Public License as published by the
1971 Free Software Foundation; either version 2 of the License, or (at your
1972 option) any later version.
1973 This program is distributed in the hope that it will be useful, but
1975 WITHOUT ANY WARRANTY; without even the implied warranty of
1976 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
1977 General Public License for more details.
1978 You should have received a copy of the GNU General Public License along
1980 with this program; if not, write to the Free Software Foundation, Inc.,
1981 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
1982
1984 To get a list of bugs against libguestfs, use this link:
1985 https://bugzilla.redhat.com/buglist.cgi?component=libguestfs&product=Virtualization+Tools
1986 To report a new bug against libguestfs, use this link:
1988 https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools
1989 When reporting a bug, please supply:
1991 • The version of libguestfs.
1993 • Where you got libguestfs (eg. which Linux distro, compiled from
1995 source, etc)
1996 • Describe the bug accurately and give a way to reproduce it.
1998 • Run libguestfs-test-tool(1) and paste the complete, unedited output
2000 into the bug report.
2001guestfs-tools-1.48.2 2022-05-26 virt-builder(1)