Libguestfs is tools and a library for accessing and modifying guest
disk images.  For more information see the home page:

  http://libguestfs.org/

For discussion, development, patches, etc. please use the mailing
list:

  http://www.redhat.com/mailman/listinfo/libguestfs


Requirements
----------------------------------------------------------------------

Running ./configure will check you have all the requirements installed
on your machine.

Fedora/RHEL users:

  A useful tip is to run:

    yum-builddep libguestfs
  or:
    dnf builddep libguestfs

  which will install all build dependencies automatically.  If that is
  successful, you don't need to bother with the rest of this section.

Debian/Ubuntu users:

  Use:

    apt-get build-dep libguestfs

  to install all build dependencies.  If that doesn't work, take a
  look at the Debian source package:
  http://packages.debian.org/source/libguestfs
  at the list of 'build-depends' and 'build-depends-indep', and
  install everything listed there.

  If either of those techniques is successful, you don't need to
  bother with the rest of this section.

The full requirements are described below.

                               R = Required
                               O = Optional
+==============+=============+===+=========================================+
| Package name | Min.version |   | Notes                                   |
+==============+=============+===+=========================================+
| Install as many packages listed in appliance/packagelist.in as possible. |
| This installs the disk management tools required by the appliance.  The  |
| list below is *additional* packages needed on the host.                  |
+--------------+-------------+---+-----------------------------------------+
| qemu         | 1.2.0       | R | 1.1 may work, but has broken virtio-scsi|
+--------------+-------------+---+-----------------------------------------+
| qemu-img     |             | R | >= 2.2.0 is required for virt-v2v but   |
|              |             |   | optional elsewhere                      |
+--------------+-------------+---+-----------------------------------------+
| kernel       | 2.6.34      | R | Make sure the following are enabled     |
|              |             |   | compiled in or as a module:             |
|              |             |   |  - virtio-pci                           |
|              |             |   |  - virtio-serial                        |
|              |             |   |  - virtio-block                         |
|              |             |   |  - virtio-net                           |
+--------------+-------------+---+-----------------------------------------+
| supermin     | 5.1.0       | R | This is required on all distros.        |
|              |             |   | 'supermin' is the new name for          |
|              |             |   | 'febootstrap'.                          |
|              |             |   | For alternatives, see:                  |
|              |             |   | libguestfs.org/download/binaries/appliance/
+--------------+-------------+---+-----------------------------------------+
| glibc        |             | R | We use various glibc-isms.              |
|              |             |   | Also glibc provides XDR, rpcgen.        |
+--------------+-------------+---+-----------------------------------------+
| GCC or LLVM  |             | R | We use __attribute__((cleanup)).        |
+--------------+-------------+---+-----------------------------------------+
| Perl         |             | R | Various build and test programs need    |
|              |             |   | Perl.  Not needed at runtime except if  |
|              |             |   | you need to run a handful of virt-*     |
|              |             |   | tools that are still written in Perl.   |
+--------------+-------------+---+-----------------------------------------+
| Pod::Man     |             | R | Part of Perl core.                      |
+--------------+-------------+---+-----------------------------------------+
| Pod::Simple  |             | R | Part of Perl core.                      |
+--------------+-------------+---+-----------------------------------------+
| OCaml        | 3.11        |R/O| Required if compiling from git.         |
|              |             |   | Optional if compiling from tarball.     |
|              |             |   | To build generated files and OCaml bindings.
+--------------+-------------+---+-----------------------------------------+
| findlib      |             |R/O| Required if compiling from git.         |
|              |             |   | Optional if compiling from tarball.     |
|              |             |   | To build generated files and OCaml bindings.
+--------------+-------------+---+-----------------------------------------+
| autotools    |             |R/O| Required if compiling from git.         |
|              |             |   | Optional if compiling from tarball.     |
|              |             |   | Autotools-based build system.           |
+--------------+-------------+---+-----------------------------------------+
| cpio         |             | R |                                         |
+--------------+-------------+---+-----------------------------------------+
| gperf        |             | R |                                         |
+--------------+-------------+---+-----------------------------------------+
| flex         |             | R | flex & bison are required for virt-     |
+--------------+-------------+---| builder.  We could make these           |
| bison        |             | R | optional but automakes makes it hard.   |
+--------------+-------------+---+-----------------------------------------+
| PCRE         |             | R | Perl-compatible Regular Expression lib. |
+--------------+-------------+---+-----------------------------------------+
| genisoimage  |             | R | mkisofs may work.                       |
+--------------+-------------+---+-----------------------------------------+
| libxml2      |             | R | Popular XML library.                    |
+--------------+-------------+---+-----------------------------------------+
| augeas       | 1.0.0       | R |                                         |
+--------------+-------------+---+-----------------------------------------+
| xz           |             | R | Used to compress disk images.           |
|              |             |   | Used by virt-builder for compression.   |
+--------------+-------------+---+-----------------------------------------+
| po4a         |             |R/O| Required if compiling from git.         |
|              |             |   | Optional if compiling from tarball.     |
|              |             |   | For localizing man pages.               |
+--------------+-------------+---+-----------------------------------------+
| hivex        | 1.2.7       |R/O| Require if compiling from git.          |
|              |             |   | Windows Registry hive parser.           |
+--------------+-------------+---+-----------------------------------------+
| libmagic     |             | O | The library used by the 'file' command. |
+--------------+-------------+---+-----------------------------------------+
| libvirt      |             | O | >= 0.10.2 is needed if you want to use  |
|              |             |   | libvirt to manage transient VMs.        |
+--------------+-------------+---+-----------------------------------------+
| xmllint      |             | O | Part of libxml2.  Used for tests only.  |
+--------------+-------------+---+-----------------------------------------+
| libconfig    |             | O | Used to parse libguestfs's own config   |
|              |             |   | files eg. /etc/libguestfs-tools.conf.   |
+--------------+-------------+---+-----------------------------------------+
| libselinux   |             | O | Used by the libvirt backend to securely |
|              |             |   | confine the appliance (sVirt).          |
+--------------+-------------+---+-----------------------------------------+
| db utils     |             | O | db_dump, db_load etc.  Usually found in |
|              |             |   | a package called db-utils, db4-utils,   |
|              |             |   | db4.X-utils, Berkeley DB utils, etc.    |
+--------------+-------------+---+-----------------------------------------+
| systemtap    |             | O | For userspace probes.                   |
+--------------+-------------+---+-----------------------------------------+
| readline     |             | O | For nicer command line in guestfish.    |
+--------------+-------------+---+-----------------------------------------+
| acl          |             | O | Library (libacl) and programs for       |
|              |             |   | handling POSIX ACLs.                    |
+--------------+-------------+---+-----------------------------------------+
| libcap       |             | O | Library (libcap) and programs for       |
|              |             |   | handling Linux capabilities.            |
+--------------+-------------+---+-----------------------------------------+
| libldm       |             | O | Library (libldm) and 'ldmtool' for      |
|              |             |   | handling Windows Dynamic Disks.         |
+--------------+-------------+---+-----------------------------------------+
| sd-journal   |             | O | systemd journal library                 |
+--------------+-------------+---+-----------------------------------------+
| yajl         | 2.0.4       | O | JSON parser for parsing output of       |
|              |             |   | ldmtool and qemu-img info commands.     |
+--------------+-------------+---+-----------------------------------------+
| gdisk        |             | O | GPT disk support.                       |
+--------------+-------------+---+-----------------------------------------+
| netpbm       |             | O | Render icons from guests.               |
+--------------+-------------+---+-----------------------------------------+
| icoutils     |             | O | Render icons from Windows guests.       |
+--------------+-------------+---+-----------------------------------------+
| Expect       |             | O | Perl module used to test virt-rescue.   |
+--------------+-------------+---+-----------------------------------------+
| FUSE         |             | O | fusermount, libfuse, and kernel module  |
|              |             |   | are all needed if you want guestmount   |
|              |             |   | and/or 'mount-local' support.           |
+--------------+-------------+---+-----------------------------------------+
| static glibc |             | O | Used for testing only.                  |
+--------------+-------------+---+-----------------------------------------+
| qemu-nbd     |             | O | Used for testing only.                  |
+--------------+-------------+---+-----------------------------------------+
| uml_mkcow    |             | O | For the UML backend.                    |
+--------------+-------------+---+-----------------------------------------+
| curl         |             | O | Used by virt-builder for downloads      |
+--------------+-------------+---+-----------------------------------------+
| gpg          |             | O | Used by virt-builder for digital        |
|              |             |   | signatures                              |
+--------------+-------------+---+-----------------------------------------+
| liblzma      |             | O | Can be used by virt-builder for fast    |
|              |             |   | uncompression of templates.             |
+--------------+-------------+---+-----------------------------------------+
| gtk2         | 2.24        | O | Used by virt-p2v user interface.        |
+--------------+-------------+---+-----------------------------------------+
| zip, unzip   |             | O | Used by virt-v2v for OVA files.         |
+--------------+-------------+---+-----------------------------------------+
| python-evtx  |             | O | Used by virt-log to parse Windows       |
|              |             |   | Event Log files.                        |
+--------------+-------------+---+-----------------------------------------+
| ocaml-gettext|             | O | For localizing OCaml virt-* tools.      |
+--------------+-------------+---+-----------------------------------------+
| Python       | 2.2         | O | For the Python bindings.                |
+--------------+-------------+---+-----------------------------------------+
| Ruby         |             | O | >= 1.9 is better than 1.8.              |
+--------------+-------------+---+-----------------------------------------+
| rake         |             | O | For the Ruby bindings.                  |
+--------------+-------------+---+-----------------------------------------+
| rubygem-minitest           | O | For the Ruby bindings.                  |
+--------------+-------------+---+-----------------------------------------+
| Java         | 1.6         | O | Java + JNI + jpackage-utils are needed  |
|              |             |   | for the Java bindings.                  |
+--------------+-------------+---+-----------------------------------------+
| GHC          |             | O | For the Haskell bindings.               |
+--------------+-------------+---+-----------------------------------------+
| PHP          |             | O | For the PHP bindings.                   |
+--------------+-------------+---+-----------------------------------------+
| phpize       |             | O | For the PHP bindings.                   |
+--------------+-------------+---+-----------------------------------------+
| glib2        |             | O | For the GObject bindings.               |
+--------------+-------------+---+-----------------------------------------+
| gobject-introspection      | O | For the GObject bindings.               |
+--------------+-------------+---+-----------------------------------------+
| gjs          |             | O | For testing the GObject bindings.       |
+--------------+-------------+---+-----------------------------------------+
| LUA          |             | O | For the LUA bindings.                   |
+--------------+-------------+---+-----------------------------------------+
| Erlang       |             | O | For the Erlang bindings.                |
+--------------+-------------+---+-----------------------------------------+
| erl_interface|             | O | For the Erlang bindings.                |
+--------------+-------------+---+-----------------------------------------+
| golang       | 1.1.1       | O | For the Go bindings.                    |
+--------------+-------------+---+-----------------------------------------+
| valgrind     |             | O | For testing for memory problems.        |
+--------------+-------------+---+-----------------------------------------+
| Sys::Virt    |             | O | Perl bindings for libvirt.              |
+--------------+-------------+---+-----------------------------------------+
| libvirt-python             | O | For testing Python libvirt/libguestfs   |
|              |             |   | interactions.                           |
+--------------+-------------+---+-----------------------------------------+
| Win::Hivex   |             | O | Perl bindings for hivex.                |
+--------------+-------------+---+-----------------------------------------+
| Pod::Usage   |             | O | Perl module used by tests.              |
+--------------+-------------+---+-----------------------------------------+
| Test::More   |             | O | Perl module used by tests.              |
+--------------+-------------+---+-----------------------------------------+
| perl-libintl |             | O | Perl module for localization.           |
+--------------+-------------+---+-----------------------------------------+
| bash-completion            | O | For tab-completion of commands in bash. |
+--------------+-------------+---+-----------------------------------------+
| ocaml-ounit  | 2.0.0       | O | For the tests of the common OCaml       |
|              |             |   | modules.                                |
+--------------+-------------+---+-----------------------------------------+
| ocaml-libvirt| 0.6.1.5     | O | For building the virt-v2v test harness. |
+==============+=============+===+=========================================+
                               R = Required
                               O = Optional


Building
----------------------------------------------------------------------

Build the daemon, library and root filesystem:

  building from tarball     building from git
  ---------------------     -----------------
    ./configure               ./autogen.sh
    make                      make

Run the tests:

  make check

Also:

 make check-valgrind

runs a subset of the test suite under valgrind (requires valgrind to
be installed obviously).

 make check-all

runs check-valgrind + even more tests, but these require that you have
some libvirt guests installed, that these guests' disks are accessible
by the current user, and these tests may fail for other reasons which
are not necessarily because of real problems.

 make help

lists all 'make' targets.

You may install the library by running the following command as root.
However *most users should probably not do this*.  Instead, './run'
the programs from the build directory as described below.

  make install

Distro packagers should use this instead:

 make INSTALLDIRS=vendor [DESTDIR=...] install

You can run guestfish, guestmount and the virt tools without needing
to install, using the "./run" script in the top directory.  This
script sets up some environment variables.  For example:

  ./run guestfish [usual guestfish args ...]

  ./run virt-inspector [usual virt-inspector args ...]

If you are already in the fish/ subdirectory, then the following
command will also work:

  ../run guestfish [...]

The ./run script adds every libguestfs binary to the $PATH, so the
above example runs guestfish from the build directory (not the
globally installed guestfish if there is one).

You can also run the C programs under valgrind like this:

  ./run valgrind [valgrind opts...] virt-cat [virt-cat opts...]

or under gdb:

  ./run gdb --args virt-cat [virt-cat opts...]

This also works with sudo (eg. if you need root access for libvirt or
to access a block device):

  sudo ./run virt-cat -d LinuxGuest /etc/passwd


qemu
----------------------------------------------------------------------

By far the most common problem is with broken or incompatible
qemu releases.

Different versions of qemu have problems booting the appliance for
different reasons.  This varies between versions of qemu, and Linux
distributions which add their own patches.

If you find a problem, you could try using your own qemu built from
source (qemu is very easy to build from source), with a 'qemu
wrapper'.  Qemu wrappers are described in the guestfs(3) manpage.


Note on using KVM
----------------------------------------------------------------------

By default the configure script will look for qemu-kvm (KVM support).
You will need a reasonably recent processor for this to work.  KVM is
much faster than using plain Qemu.

You may also need to enable KVM support for non-root users, by following
these instructions:

  http://www.linux-kvm.org/page/FAQ#How_can_I_use_kvm_with_a_non-privileged_user.3F

On some systems, this will work too:

  chmod 0666 /dev/kvm

On some systems, the chmod will not survive a reboot, and you will
need to make edits to the udev configuration.


Mirroring tip
----------------------------------------------------------------------

On my machines I can usually rebuild the appliance in around 3
minutes.  If it takes much longer for you, use a local distro mirror
or squid.

To use squid to cache yum downloads, read this first:
https://lists.dulug.duke.edu/pipermail/yum/2006-August/009041.html
(In brief, because yum chooses random mirrors each time, squid doesn't
work very well with default yum configuration.  To get around this,
choose a Fedora mirror which is close to you, set this with
'./configure --with-mirror=[...]', and then proxy the whole lot
through squid by setting http_proxy environment variable).

You will also need to substantially increase the squid configuration
limits:
http://fedoraproject.org/wiki/Using_Mock_to_test_package_builds#Using_Squid_to_Speed_Up_Mock_package_downloads


Porting to other Linux distros / non-Linux
----------------------------------------------------------------------

libguestfs itself should be fairly portable to other Linux
distributions.  Non-Linux ports are trickier, but we will accept
patches if they aren't too invasive.

The main porting issues are with the dependencies needed to build the
appliance.  You will need to port supermin first
(http://people.redhat.com/~rjones/supermin/).


Note on using clang (from LLVM) instead of GCC
----------------------------------------------------------------------

  export CC=clang
  ./configure --disable-probes
  make

SystemTap/DTrace-style userspace probe points don't work under the
clang compiler, which is why you may need to disable them.

Don't enable GCC warnings (ie. *don't* use
'./configure --enable-gcc-warnings').


Copyright and license information
----------------------------------------------------------------------

Copyright (C) 2009-2015 Red Hat Inc.

The library is distributed under the LGPLv2+.  The programs are
distributed under the GPLv2+.  Please see the files COPYING and
COPYING.LIB for full license information.

The examples are under a very liberal license.